US20210008625A1 - Molybdenum material and method for manufacturing the same - Google Patents

Molybdenum material and method for manufacturing the same Download PDF

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US20210008625A1
US20210008625A1 US16/981,440 US201916981440A US2021008625A1 US 20210008625 A1 US20210008625 A1 US 20210008625A1 US 201916981440 A US201916981440 A US 201916981440A US 2021008625 A1 US2021008625 A1 US 2021008625A1
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length
capsule
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sample
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US16/981,440
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Akihiro Yoshida
Takanori Kadokura
Tomohiro Takida
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ALMT Corp
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ALMT Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/1208—Containers or coating used therefor
    • B22F3/1258—Container manufacturing
    • B22F3/1291—Solid insert eliminated after consolidation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/14—Both compacting and sintering simultaneously
    • B22F3/15—Hot isostatic pressing
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C22C1/04—Making non-ferrous alloys by powder metallurgy
    • C22C1/045—Alloys based on refractory metals
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C27/00—Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
    • C22C27/04—Alloys based on tungsten or molybdenum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2301/00—Metallic composition of the powder or its coating
    • B22F2301/20—Refractory metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F5/10—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of articles with cavities or holes, not otherwise provided for in the preceding subgroups
    • B22F5/106—Tube or ring forms

Definitions

  • the present invention relates to a molybdenum material.
  • the present application claims priority based on Japanese Patent Application No. 2018-063888 filed on Mar. 29, 2018. The entire contents described in the Japanese patent application are incorporated herein by reference.
  • a molybdenum material according to one aspect of the present invention is a molybdenum material having a diameter of 75 mm or more and a length of 250 mm or more, and having a relative density of 99.5% or more.
  • FIG. 1 is a cross section of molybdenum powder introduced in a container.
  • FIG. 2 is a cross section of a container and molybdenum powder compressed by HIP.
  • FIG. 3 is a cross section of a sintered molybdenum body removed from the container.
  • FIG. 4 is a perspective view of a disc cut out of a molybdenum material.
  • FIG. 5 is a perspective view for illustrating a portion of the disc from which a test piece is extracted.
  • a molybdenum material according to one embodiment of the present invention is a molybdenum material having a diameter of 75 mm or more and a length of 250 mm or more, and having a relative density of 99.5% or more.
  • the molybdenum material has a relative density of 99.9% or more.
  • the molybdenum material contains 99.9% by mass or more of molybdenum.
  • the molybdenum material contains 0.3% by mass or more and 1.5% by mass or less of titanium, 0.03% by mass or more and 0.1% by mass or less of zirconium, and 0.01% by mass or more and 0.3% by mass or less of carbon, with a balance composed of molybdenum and unavoidable impurity.
  • a method for manufacturing a molybdenum material preferably comprises: (1) preparing a first core alloy having an outer diameter of 40 mm or less by hot isostatic pressing; (2) disposing the first core alloy in a tube having a diameter larger than that of the first core alloy; (3) disposing molybdenum powder in the tube around the first core alloy and subsequently compressing the tube by hot isostatic pressing; (4) removing the compressed tube to form a second core alloy having a diameter larger than that of the first core alloy; and repeating the steps (2) to (4).
  • W powder having a particle size of 4.1 ⁇ m was pressed with a pressure of 200 MPa by CIP (Cold Isostatic Pressing) and sintered in a hydrogen atmosphere having a temperature of 2250° C. to obtain a sintered rod having a relative density of 92%.
  • the sintered rod was pressed by HIP (Hot Isostatic Pressing) at a temperature of 1750° C. and a pressure of 195 MPa for 3 hours to obtain a sintered rod having a relative density of 97.9%.
  • a radial forging machine is used to form the rod with a forming degree of 67% to obtain a tungsten rod having an overall average relative density of 99.66% and having a relative core density of 99.63%.
  • the rod is annealed at a temperature of 1800° C. for 4 hours, it provides a crystal grain size, that is, about 800 crystal grains on average per square millimeter at a center portion of the rod and about 850 crystal grains on average per square millimeter at peripheral portion of the rod.
  • Mo powder having an average particle size of 45 ⁇ m or less is introduced into a soft steel can, and subsequently, the soft steel can is heated at 400° C. and vacuum-degassed, and thus sealed.
  • the soft steel can was pressed by HIP at a temperature of 1250° C. and a pressure of 148 MPa for 5 hours to provide a Mo sintered body having a relative density of 99.8%.
  • the Mo sintered body is cut to provide a plate having a length of 380 mm, a width of 110 mm, and a thickness of 8.1 mm, and the plate is heated to 700° C. and subsequently subjected to plastic working by rolling in a temperature range of 200° C. or higher to obtain a thickness of 4.6 mm.
  • the resulting, sintered alloy tends to have an inner portion having a lower density and a peripheral portion having a higher density. This unevenness in density between the inner portion and the peripheral portion increases as the product's size increases.
  • a large stress must be applied to the Mo material by hot working.
  • a Mo sintered body can be produced in a stepwise manner from a center side toward a peripheral side to have an overall high density to obtain a rod-shaped Mo material having a diameter of 75 mm or more which has not conventionally been achieved.
  • the Mo material By using the Mo material, a large number of components having uniform density can be obtained.
  • the Mo material When the Mo material is used for a target, the Mo material, having a uniform density, allows a large number of wafers which are uniformly consumed and thus have good consumability to be obtained.
  • the Mo material is used for a heater, the Mo material allows a large number of heating elements with small variation in electrical resistance and less likely to break to be obtained.
  • the Mo material When the Mo material is used for a furnace material, the Mo material allows a large number of members having uniform material strength to be obtained. When the Mo material is used for an electrode for resistance welding, the Mo material, having a uniform density, allows a large number of electrodes with small variation in bonding conditions to be obtained.
  • the Mo material has a diameter of 75 mm or more.
  • the Mo material preferably has a diameter of 300 mm or less.
  • the Mo material can be used for a large-volume component, for example, the aforementioned target, heater, furnace material, or electrode for resistance welding.
  • the Mo material has a diameter of 140 mm or more. More preferably, the Mo material has a diameter of 200 mm or more.
  • the Mo material may have any diameter equal to or larger than 75 mm, it is preferably 300 mm or less from the viewpoint of actual use.
  • the diameter of the Mo material is measured in a method as follows: the Mo material have a plurality of any portions thereof measured in diameter with a caliper, and an average value of maximum and minimum diameters measured is defined as the diameter of the Mo material.
  • Variation in diameter of the Mo material is preferably 20% or less.
  • the Mo material has a variation in diameter exceeding 20%, and a black skin formed on a periphery of the Mo material is removed by machining, it could be difficult to remove the black skin.
  • the word “could” is intended to mean that there is a slight possibility that something will happen, and is not intended to mean that there is a high probability that it will happen.
  • the Mo material is not limited in shape to a cylindrical shape, and may have a polygonal shape.
  • the diameter of an imaginary circle having a maximum area inside the polygonal shape is defined as the diameter of the Mo material.
  • the Mo material is measured in density at a portion inside the imaginary circle having the maximum area.
  • the Mo material has a length of 250 mm or more.
  • the Mo material preferably has a length of 1500 mm or less.
  • the Mo material has a length of 250 mm or more, and, for example, the aforementioned components are formed of the Mo material, a large number of such components can be obtained from the Mo material at a time.
  • the Mo material has a length of less than 250 mm, it could provide a small yield of such components and hence poor production efficiency.
  • a conventional process can also enhance the density of a center portion of the Mo material.
  • the Mo material may have any length equal to or larger than 250 mm, it is preferably 1500 mm or less from the viewpoint of actual use.
  • the Mo material internally has a relative density of 99.5% or more.
  • the Mo material internally has a relative density of 99.5% or more, and a large number of the aforementioned components are obtained from each portion of the Mo material, the components can have a small difference in density.
  • Mo material internally has a relative density of 99.9% or more. More preferably, the Mo material internally has a relative density of 100%.
  • the Mo material internally has a relative density of less than 99.5%, it could provide components with a large unevenness in density therebetween, and hence variation in characteristics as components.
  • the Mo material's internal relative density is measured in the following method. Note that in the following description, the Mo material's relative density may simply be referred to as relative density.
  • a disc having a thickness of 30 mm is cut out of the obtained rod-shaped Mo material at its opposite ends and center portion in its longitudinal direction for a total of three locations. As locations for evaluation, a total of three portions of each disc cut out, i.e., a portion in a vicinity of a surface, a center, and an intermediate portion between the vicinity of the surface and the center in the radial direction of the disc, are selected, and a test piece of 10 ⁇ 10 ⁇ 10 mm is cut out therefrom and subjected to measurement in relative density of the Mo material in Archimedes' method.
  • the Mo material's relative density is calculated from the composition of the Mo material, a theoretical density calculated from the composition of the Mo material, the volume of the test piece, and the mass of the test piece.
  • the volume of the test piece is a volume corresponding to an increase of water in level in a beaker when the test piece is put in the beaker for the sake of illustration.
  • the mass of the test piece is measured with an electronic balance.
  • the Mo material's relative density is determined by the following equation:
  • Mo material's relative density (mass of test piece/volume of test piece)/theoretical density
  • the theoretical density is determined by the composition of the Mo material.
  • the Mo material may contain 99.9% by mass or more of Mo.
  • this Mo material is compared with a Mo material having a Mo content of less than 99.9% by mass, the former has better machinability and plastic workability than the latter.
  • the Mo material may contain 0.3% by mass or more and 1.5% by mass or less of Ti, 0.03% by mass or more and 0.1% by mass or less of Zr, and 0.01% by mass or more and 0.3% by mass or less of C, with a balance composed of Mo, unavoidable impurity and unavoidable gaseous impurity.
  • the former can have higher mechanical strength than the latter.
  • the unavoidable impurity for example includes at least one of Al, Ca, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sn, Si, Na, K and W.
  • the unavoidable gaseous impurity for example includes at least one of N and O.
  • the Mo material preferably contains 0.1% by mass or less of unavoidable impurity in a total amount.
  • the Mo material preferably contains 0.01% by mass or less of unavoidable gaseous impurity in a total amount.
  • the Mo material When the Mo material has a Ti content in mass exceeding 1.5% by mass, the Mo material could fail to have a sufficient density. When the Mo material has a Ti content in mass of less than 0.3% by mass, the Mo material could fail to have a strength exceeding that of pure Mo. Note that pure Mo is a material of molybdenum having a Mo content in mass of 99.9% by mass or more.
  • the Mo material When the Mo material has a Zr content in mass exceeding 0.1% by mass, the Mo material could fail to have a sufficient density. When the Mo material has a Zr content in mass of less than 0.03% by mass, the Mo material could fail to have a strength exceeding that of pure Mo.
  • the Mo material When the Mo material has a C content in mass exceeding 0.3% by mass, the Mo material could fail to have a sufficient density. When the Mo material has a C content in mass of less than 0.01% by mass, the Mo material could fail to have a strength exceeding that of pure Mo.
  • the Mo material contains unavoidable impurity in a total amount exceeding 0.1% by mass, the Mo material could fail to have a sufficient density and stable characteristics.
  • the Mo material contains unavoidable gaseous impurity exceeding 0.01% by mass in a total amount, the Mo material could fail to have a sufficient density and stable characteristics.
  • the composition of metal elements is measured through ICP (Inductively Coupled Plasma Emission Spectroscopy) according to JIS H1404 (2001).
  • ICPS-8100 manufactured by Shimadzu Corporation is used to measure metal elements through ICP.
  • C is measured with EMIA-920-V2 manufactured by HORIBA, Ltd.
  • O and N are measured with ON-836 manufactured by LECO JAPAN CORPORATION.
  • the Mo material preferably has a tensile strength of 400 MPa or more at room temperature and a tensile strength of 50 MPa or more at 1000° C. When the Mo material does not satisfy these tensile strengths, and for example it is used for a furnace material, the Mo material could be deformed in use.
  • the Mo material preferably includes, per square centimeter, no pore having a diameter of 30 ⁇ m or more and 200 or less pores having a diameter of less than 30 ⁇ m.
  • the number of pores included in the Mo material is counted in the following method.
  • a disc-shaped sample having a thickness of 15 mm and a diameter of 10 mm is cut out of the obtained rod-shaped Mo material at the center and in a vicinity of a surface in the radial direction.
  • Each sample has a cut surface polished to have a polished surface with a surface roughness (Rz) of 0.2 ⁇ m or less.
  • the sample is polished for example as follows: the cut surface is polished with a waterproof paper of #180 to 2000 and subsequently buff-polished using a suspension of diamond having a particle size of 1 to 3 ⁇ m.
  • the sample's polished surface is observed with a stereomicroscope SZ40 manufactured by Olympus Corporation, and where a pore having a maximum diameter is located is confirmed.
  • a range extracted from the polished surface of the sample including the location of the pore having the maximum diameter is observed at a magnification of 1000 times with a microscope VHX-6000 manufactured by Keyence Corporation to measure the maximum diameter of the pore.
  • the maximum diameter of the pore is defined as the diameter of the inscribed circle of the observed pore.
  • the extracted range is within a circle having a radius of 4 mm from the center of the polished surface of the sample having a diameter of 10 mm.
  • the extracted range is enlarged by 100 times, and what has a different matrix and a different contrast is all determined as void and extracted, and subjected to contamination analysis to count the number of pores. In doing so, the number of pores is counted with an extraction parameter adjusted so that the pore's maximum diameter matches a measured value thereof as observed at the magnification of 1000 times.
  • the Mo material includes, per square centimeter, pores having a diameter of 30 ⁇ m or more and more than 200 pores having a diameter of less than 30 ⁇ m, and the Mo material is used for example for a target, a film formed by sputtering could have large variation in thickness.
  • Mo powder having an Fsss value of 4.0 ⁇ m as measured in the Fisher method was used as a raw material.
  • the Fsss value is preferably 3 ⁇ m or more and 10 ⁇ m or less.
  • An Fsss value exceeding 10 ⁇ m could result in a Mo sintered body failing to have an overall increased density.
  • An Fsss value of less than 3 ⁇ m could result in a Mo sintered body failing to have a center portion with an increased density.
  • Pure Mo powder was used as raw material powder.
  • Example 1 Mo materials of Sample Nos. 1 to 3 and 101 shown in Table 1 were produced.
  • Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 1, 60 mm for sample No. 2, 77 mm for sample No. 3, and 135 mm for sample No. 101. Capsule 21 is a soft steel can. Note, however, that capsule 21 is not limited in material to soft steel.
  • a lid 22 having a hot-degassing pipe 23 welded thereto was welded to capsule 21 using TIG (Tungsten Inert Gas).
  • TIG Tungsten Inert Gas
  • a hose connected to an oil rotary pump and an oil diffusion pump was attached to a tip 25 of pipe 23 .
  • a container with capsule 21 having lid 22 welded thereto was placed in an atmospheric furnace held at a temperature of 500° C. and vacuumed using the oil rotary pump and the oil diffusion pump so that the container had an internal pressure reduced from normal atmospheric pressure to 1 ⁇ 10 ⁇ 3 Pa.
  • the container thus hot-degassed was extracted and had pipe 23 collapsed at a position to be provided with a seal portion 24 , and cut off at the collapsed portion, and the cut pipe had an end TIG-welded and thus sealed to have seal portion 24 .
  • the soft steel can preferably has a thickness of 3 mm or more and 20 mm or less.
  • the soft steel can has a thickness exceeding 20 mm, and pressure-sintered, the resulting Mo alloy could fail to have an increased density.
  • capsule 21 could be broken.
  • Capsule 21 may have a circumference and a bottom formed integrally, and when capsule 21 has a large size, the capsule may have a circumference and a bottom that are separate members TIG-welded and thus bonded together.
  • Lid 22 can for example be a plate material having the same thickness as capsule 21 .
  • the furnace In hot-degassing the container, the furnace preferably has an internal temperature of 400° C. or higher and 500° C. or lower. When the furnace's temperature exceeds 500° C., and the container internally has a low degree of vacuum, the Mo powder could be oxidized. When the furnace's temperature is lower than 400° C., a gas component or the like adsorbed on the Mo powder could be insufficiently degassed, and the Mo alloy may have pores therein.
  • the container is hot-degassed preferably for 1 hour or more and 5 hours or less after capsule 21 attains the same temperature as that of the interior of the furnace. Once a period of time for which the container is hot-degassed exceeds 5 hours, the Mo alloy no longer has its characteristics improved, and hot-degassing the container for a period of time exceeding 5 hours thus results in impaired economy.
  • a gas component or the like adsorbed on the Mo powder could be insufficiently degassed, and the Mo alloy may have pores therein.
  • the container When the container is hot-degassed, its internal ultimate pressure is preferably less than 1 ⁇ 10 ⁇ 2 Pa. When the container's internal ultimate pressure is 1 ⁇ 10 ⁇ 2 Pa or more, the container could be insufficiently degassed, and when it is HIPed, the Mo alloy's density could be less likely to increase.
  • the Mo powder in the container preferably has a bulk density of 2.5 g/cm 3 or more and 5.0 g/cm 3 or less.
  • a gas component or the like adsorbed on the Mo powder could be insufficiently degassed, and the Mo alloy's density could be less likely to increase.
  • the Mo powder has a bulk density of less than 2.5 g/cm 3 , and is HIPed, the Mo alloy's shrinkability is excessively large, and a resulting Mo sintered body could fail to have a targeted shape.
  • the Mo powder in the container has a bulk density of 3.5 g/cm 3 or more and 4.5 g/cm 3 or less.
  • the sealed container was placed in a furnace of a hot isostatic pressing apparatus and subjected to pressure-sintering by HIP at a temperature of 1280° C. and a pressure of 147 MPa for 5 hours.
  • pressure-sintering by HIP may simply be referred to as HIP.
  • the container had an internal volume reduced by HIP.
  • Sintered core body 11 is sized as shown in Table 1.
  • Sintered core body 11 had its relative density measured in Archimedes' method, and it had a relative density of 99.5% or more and 99.9% or less at a center portion in the radial direction and a relative density of 100% at a portion other than the center portion.
  • the HIP is performed with a heating temperature preferably of 1000° C. or higher and 1350° C. or lower. When the heating temperature exceeds 1350° C., it is a temperature close to the melting point of the soft steel constituting capsule 21 , and capsule 21 could be broken during the HIP. When the heating temperature is lower than 1000° C., the Mo alloy's density could fail to increase during the HIP.
  • the container's internal ultimate pressure is preferably 98 MPa or more and 250 MPa or less. Once the container's internal ultimate pressure exceeds 250 MPa, the Mo alloy's density no longer increases, and HIPing the container beyond 250 MPa results in impaired economy. When the container's internal ultimate pressure is less than 98 MPa, the Mo alloy's density could fail to increase.
  • the HIP is applied preferably for 1 hour or more and 10 hours or less. Applying the HIP beyond 10 hours does not further increase the Mo alloy's density, and HIPing the container beyond 10 hours results in impaired economy. When the HIP is applied for less than 1 hour, the Mo alloy's density could fail to increase.
  • the Mo alloy's machining margin is preferably 3 mm or more and 10 mm or less.
  • the Mo alloy's machining margin exceeds 10 mm it results in an increased processing time and a reduced yield of material, and hence impaired economy.
  • the Mo alloy's machining margin is less than 3 mm, the soft steel can could be incompletely removed from the Mo alloy.
  • capsules 21 of three soft steel cans each shown in FIG. 1 were prepared.
  • Capsule 21 had a thickness of 10 mm and a length of 1600 mm.
  • Capsules 21 had inner diameters of 80 mm for sample No. 1, 90 mm for sample No. 2, and 100 mm for sample No. 3.
  • Sintered core body 11 was disposed at the center of capsule 21 , and the raw material described in the “(1-1) raw material” section was introduced between capsule 21 and sintered core body 11 . Through the process described in the “(1-2) core alloy” section, the container was hot-degassed at a temperature of 400° C. and sealed.
  • capsules 21 of three soft steel cans each shown in FIG. 1 were prepared.
  • Capsule 21 had a thickness of 10 mm and a length of 1600 mm.
  • Capsules 21 had inner diameters of 102 mm for sample No. 1, 95 mm for sample No. 2, and 88 mm for sample No. 3.
  • Each Mo sintered body was disposed at the center of capsule 21 , and the raw material described in the “(1-1) raw material” section was introduced between capsule 21 and sintered core body 11 . Through the process described in the “(1-2) core alloy” section, the container was hot-degassed at a temperature of 400° C. and sealed.
  • test pieces were cut out of each disc at locations for evaluation, that is, as seen in the radial direction of the disc, a location 4 at the circumference, a location 6 at the center, and a location 5 between the circumference and the center, and subjected to measurement of relative density. A result thereof is shown in Table 1.
  • Example 2 sintered core body 11 was produced in the same manner as in Example 1 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed twice to have an increased diameter to thus produce Mo materials for Sample Nos. 4 to 6.
  • a Mo material for Sample No. 102 was produced in the same manner as Sample No. 101 except that the length was 1000 mm.
  • test pieces were cutout and subjected to measurement of relative density. A result thereof is shown in Table 2.
  • Example 3 sintered core body 11 was produced in the same manner as in Example 1 except that the length was 500 mm, and sintered core body 11 was additionally HIPed twice to have an increased diameter to thus produce Mo materials for Sample Nos. 7 to 9.
  • a Mo material for Sample No. 103 was produced in the same manner as Sample No. 101 except that the length was 500 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 3.
  • Example 4 As shown in Table 3, it has been confirmed that the Mo materials of Sample Nos. 7 to 9 of Example 3 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 7 and 8 of Example 3 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 103 as the Comparative Example had a relative density including a portion less than 99.5%.
  • Example 4 sintered core body 11 was produced in the same manner as in Example 1 except that the length was 250 mm, and sintered core body 11 was additionally HIPed twice to have an increased diameter to thus produce Mo materials for Sample Nos. 10 to 12.
  • a Mo material for Sample No. 104 was produced in the same manner as Sample No. 101 except that the length was 250 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 4.
  • Example 5 in order to obtain sintered core bodies 11 for Sample Nos. 13 to 15, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 13, 60 mm for sample No. 14, and 77 mm for sample No. 15. Sintered core body 11 was produced in the same manner as in Example 1, and additionally HIPed twice or three times to have an increased diameter of 100 mm to thus produce Mo materials for Sample Nos. 13 to 15. For a comparative example, a Mo material for Sample No. 105 was produced in the same manner as Sample No. 101 except that the diameter was 100 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 5.
  • Example 6 sintered core body 11 was produced in the same manner as in Example 5 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed twice or three times to have an increased diameter to thus produce Mo materials for Sample Nos. 16 to 18.
  • a Mo material for Sample No. 106 was produced in the same manner as Sample No. 105 except that the length was 1000 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 6.
  • capsule's inner diameter, sintered body's and diameter & length after additional HIP (mm) final diameter 100 mm sintered core 1st time 2nd time 3rd time sample body size (mm) capsule's capsule's capsule's no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length ex. 6 16 20 1000 80 50 1000 110 80 1000 123 100 1000 17 30 1000 90 60 1000 120 90 1000 117 100 1000 18 40 1000 100 70 1000 130 100 1000 comp. ex. 106 100 1000 sintered body's relative density (%) final diameter: 100 mm front end 1 center 2 rear end 3 sample loc. loc. loc. loc. loc. loc. loc. loc. no. 4 5 6 4 5 6 4 5 6 ex. 6 16 100 100 100 100 100 100 100 100 100 100 100 100 17 100 100 99.9 100 100 99.9 100 100 100 18 100 99.9 99.5 100 100 99.7 100 100 99.7 comp. ex. 106 100 100 99.1 100 100 99.1 100 100 99.2
  • Example 7 sintered core body 11 was produced in the same manner as in Example 5 except that the length was 500 mm, and sintered core body 11 was additionally HIPed twice or three times to have an increased diameter to thus produce Mo materials for Sample Nos. 19 to 21.
  • a Mo material for Sample No. 107 was produced in the same manner as Sample No. 105 except that the length was 500 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 7.
  • Example 8 sintered core body 11 was produced in the same manner as in Example 5 except that the length was 250 mm, and sintered core body 11 was additionally HIPed twice or three times to have an increased diameter to thus produce Mo materials for Sample Nos. 22 to 24.
  • a Mo material for Sample No. 108 was produced in the same manner as Sample No. 105 except that the length was 250 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 8.
  • capsule's inner diameter, sintered body's and diameter & length after additional HIP (mm) final diameter 100 mm sintered core 1st time 2nd time 3rd time sample body size (mm) capsule's capsule's capsule's no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length ex. 8 22 20 250 80 50 250 110 80 250 123 100 250 23 30 250 90 60 250 120 90 250 117 100 250 24 40 250 100 70 250 130 100 250 comp. ex. 108 100 250 sintered body's relative density (%) final diameter: 100 mm front end 1 center 2 rear end 3 sample loc. loc. loc. loc. loc. loc. loc. no. 4 5 6 4 5 6 4 5 6 ex.
  • Example 9 in order to obtain sintered core bodies 11 for Sample Nos. 25 to 27, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 25, 60 mm for sample No. 26, and 77 mm for sample No. 27.
  • Sintered core body 11 was produced in the same manner as in Example 1, and additionally HIPed four or five times to have an increased diameter of 150 mm to thus produce Mo materials for Sample Nos. 25 to 27.
  • a Mo material for Sample No. 109 was produced in the same manner as Sample No. 101 except that the diameter was 150 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 9 and 10.
  • capsule's inner diameter, sintered body's and diameter & length after additional HIP (mm) final diameter 150 mm sintered core 1st time 2nd time 3rd time sample body size (mm) capsule's capsule's capsule's no. diam. length inner diam. diam. length inner diam. diam. length ex. 9 25 20 1500 80 50 1500 110 80 1500 140 110 1500 26 30 1500 90 60 1500 120 90 1500 150 120 1500 27 40 1500 100 70 1500 130 100 1500 160 130 1500 comp. ex. 109
  • Example 10 sintered core body 11 was produced in the same manner as in Example 9 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed four or five times to have an increased diameter to thus produce Mo materials for Sample Nos. 28 to 30.
  • a Mo material for Sample No. 110 was produced in the same manner as Sample No. 109 except that the length was 1000 mm.
  • test pieces were cutout and subjected to measurement of relative density. A result thereof is shown in Tables 11 and 12.
  • Example 11 sintered core body 11 was produced in the same manner as in Example 9 except that the length was 500 mm, and sintered core body 11 was additionally HIPed four or five times to have an increased diameter to thus produce Mo materials for Sample Nos. 31 to 33.
  • a Mo material for Sample No. 111 was produced in the same manner as Sample No. 109 except that the length was 500 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 13 and 14.
  • Example 12 sintered core body 11 was produced in the same manner as in Example 9 except that the length was 250 mm, and sintered core body 11 and additionally HIPed four or five times to have an increased diameter to thus produce Mo materials for Sample Nos. 34 to 36.
  • a Mo material for Sample No. 112 was produced in the same manner as Sample No. 109 except that the length was 250 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 15 and 16.
  • Example 13 in order to obtain sintered core bodies 11 for Sample Nos. 37 to 39, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 37, 60 mm for sample No. 38, and 77 mm for sample No. 39.
  • Sintered core body 11 was produced in the same manner as in Example 1, and additionally HIPed six or seven times to have an increased diameter of 220 mm to thus produce Mo materials for Sample Nos. 37 to 39.
  • a Mo material for Sample No. 113 was produced in the same manner as Sample No. 101 except that the diameter was 220 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 17 and 18.
  • Example 14 sintered core body 11 was produced in the same manner as in Example 13 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed six or seven times to have an increased diameter to thus produce Mo materials for Sample Nos. 40 to 42.
  • a Mo material for Sample No. 110 was produced in the same manner as Sample No. 113 except that the length was 1000 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 19 and 20.
  • Example 15 sintered core body 11 was produced in the same manner as in Example 13 except that the length was 500 mm, and sintered core body 11 was additionally HIPed six or seven times to have an increased diameter to thus produce Mo materials for Sample Nos. 43 to 45.
  • a Mo material for Sample No. 115 was produced in the same manner as Sample No. 113 except that the length was 500 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 21 and 22.
  • Example 16 sintered core body 11 was produced in the same manner as in Example 13 except that the length was 250 mm, and sintered core body 11 was additionally HIPed six or seven times to have an increased diameter to thus produce Mo materials for Sample Nos. 46 to 48.
  • a Mo material for Sample No. 116 was produced in the same manner as Sample No. 113 except that the length was 250 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 23 and 24.
  • Example 17 in order to obtain sintered core bodies 11 for Sample Nos. 49 to 51, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 49, 60 mm for sample No. 50, and 77 mm for sample No. 51.
  • Sintered core body 11 was produced in the same manner as in Example 1, and additionally HIPed nine or ten times to have an increased diameter of 300 mm to thus produce Mo materials for Sample Nos. 49 to 51.
  • a Mo material for Sample No. 117 was produced in the same manner as Sample No. 101 except that the diameter was 300 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 25 and 26.
  • Example 18 sintered core body 11 was produced in the same manner as in Example 17 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed nine or ten times to have an increased diameter to thus produce Mo materials for Sample Nos. 52 to 54.
  • a Mo material for Sample No. 118 was produced in the same manner as Sample No. 117 except that the length was 1000 mm.
  • test pieces were cutout and subjected to measurement of relative density. A result thereof is shown in Tables 27 and 28.
  • Example 19 sintered core body 11 was produced in the same manner as in Example 17 except that the length was 500 mm, and sintered core body 11 was additionally HIPed nine or ten times to have an increased diameter to thus produce Mo materials for Sample Nos. 55 to 57.
  • a Mo material for Sample No. 119 was produced in the same manner as Sample No. 117 except that the length was 500 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 29 and 30.
  • Example 20 sintered core body 11 was produced in the same manner as in Example 17 except that the length was 250 mm, and sintered core body 11 was additionally HIPed nine or ten times to have an increased diameter to thus produce Mo materials for Sample Nos. 58 to 60.
  • a Mo material for Sample No. 120 was produced in the same manner as Sample No. 117 except that the length was 250 mm.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 31 and 32.
  • the Mo material can have a relative density of 99.5% or more, and furthermore, the Mo material can also have a relative density of 99.9% or more.
  • Mo materials for Sample Nos. 301 to 303 and 601 were produced in the same manner as in Example 17 except that the Mo materials had a composition changed by adding a Ti component, a Zr component and a C component to a Mo component of a raw material. Specifically, Mo powder, TiC powder, and ZrC powder were mixed together to prepare raw material powder.
  • the Mo powder had an Fsss value of 4.0 ⁇ m.
  • the TiC powder had an Fsss value of 2.0 ⁇ m.
  • the ZrC powder had an Fsss value of 3.0 ⁇ m.
  • the Mo powder preferably has an Fsss value of 3 ⁇ m or more and 10 ⁇ m or less. When the Mo powder has an Fsss value exceeding 10 ⁇ m, it could result in a Mo sintered body failing to have an overall increased density. When the Mo powder has an Fsss value of less than 3 ⁇ m, it could result in a Mo sintered body failing to have a center portion with an increased density.
  • the TiC powder preferably has an Fsss value of 1 ⁇ m or more and 20 ⁇ m or less. When the TiC powder has an Fsss value exceeding 20 ⁇ m, it could result in a Mo sintered body failing to have an overall increased density.
  • the TiC powder When the TiC powder has an Fsss value of less than 1 ⁇ m, it could result in a Mo sintered body failing to have a center portion with an increased density.
  • the ZrC powder preferably has an Fsss value of 1 ⁇ m or more and 20 ⁇ m or less. When the ZrC powder has an Fsss value exceeding 20 ⁇ m, it could result in a Mo sintered body failing to have an overall increased density. When the ZrC powder has an Fsss value of less than 1 ⁇ m, it could result in a Mo sintered body failing to have a center portion with an increased density.
  • pure TiC powder pure Ti powder or TiH powder may be mixed.
  • pure ZrC powder pure Zr powder or ZrH powder may be mixed.
  • C powder is mixed with raw material powder.
  • C powder may also be mixed with raw material powder when TiC powder and ZrC powder are used.
  • the C powder preferably has an Fsss value of 0.1 ⁇ m or more and 10 ⁇ m or less. When the C powder has an Fsss value exceeding 10 ⁇ m, it could result in a Mo sintered body failing to have an overall increased density. When the C powder has an Fsss value of less than 0.1 ⁇ m, it could result in a Mo sintered body failing to have a center portion with an increased density.
  • pure Ti is a titanium material having a Ti content in mass of 99.9% by mass or more.
  • pure Zr is a zirconium material having a Zr content in mass of 99.9% by mass or more.
  • Table 33 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 21.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 34 and 35.
  • Example 22 Mo materials for Sample Nos. 401 to 403 and 602 were produced in the same manner as in Example 21 except for the compositions of the Mo materials.
  • Table 36 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 22.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 37 and 38.
  • Example 23 Mo materials for Sample Nos. 501 to 503 and 603 were produced in the same manner as in Example 21 except for the compositions of the Mo materials.
  • Table 39 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 23.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 40 and 41.
  • a Mo material that contains 0.3% by mass or more and 1.5% by mass or less of titanium, 0.03% by mass or more and 0.1% by mass or less of zirconium, and 0.01% by mass or more and 0.3% by mass or less of carbon, with a balance composed of molybdenum and unavoidable impurity can also have a relative density of 99.5% or more, and furthermore, can also have a relative density of 99.9% or more.
  • Example 24 Mo materials for Sample Nos. 701 to 705 and 601 were produced in the same manner as in Example 21 except that HIP was not additionally performed.
  • Table 42 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 24.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 43.
  • Example 25 Mo materials for Sample Nos. 801 to 805 and 602 were produced in the same manner as in Example 22 except that HIP was not additionally performed.
  • Table 44 shows a content in mass of each component according to weighed value of raw material powder and content in mass of each component according to a measured value of a composition of each Mo material in Example 25.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 45.
  • Example 26 Mo materials for Sample Nos. 901 to 905 and 603 were produced in the same manner as in Example 23 except that HIP was not additionally performed.
  • Table 46 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 26.
  • test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 47.
  • a Mo material that contains 0.3% by mass or more and 1.5% by mass or less of titanium, 0.03% by mass or more and 0.1% by mass or less of zirconium, and 0.01% by mass or more and 0.3% by mass or less of carbon, with a balance composed of molybdenum and unavoidable impurity can also have a relative density of 99.5% or more, and furthermore, can also have a relative density of 99.9% or more.

Abstract

A molybdenum material having a diameter of 75 mm or more and a length of 250 mm or more, and having a relative density of 99.5% or more.

Description

    TECHNICAL FIELD
  • The present invention relates to a molybdenum material. The present application claims priority based on Japanese Patent Application No. 2018-063888 filed on Mar. 29, 2018. The entire contents described in the Japanese patent application are incorporated herein by reference.
    • BACKGROUND ART
  • Conventional molybdenum materials are disclosed, for example, in Japanese Patent Laying-Open Nos. 2007-169789 and 2007-113033.
    • CITATION LIST Patent Literature
    • [PTL 1] Japanese Patent Laying-Open No. 2007-169789
    • [PTL 2] Japanese Patent Laying-Open No. 2007-113033
    SUMMARY OF INVENTION
  • A molybdenum material according to one aspect of the present invention is a molybdenum material having a diameter of 75 mm or more and a length of 250 mm or more, and having a relative density of 99.5% or more.
    • BRIEF DESCRIPTION OF DRAWINGS
  • FIG. 1 is a cross section of molybdenum powder introduced in a container.
  • FIG. 2 is a cross section of a container and molybdenum powder compressed by HIP.
  • FIG. 3 is a cross section of a sintered molybdenum body removed from the container.
  • FIG. 4 is a perspective view of a disc cut out of a molybdenum material.
  • FIG. 5 is a perspective view for illustrating a portion of the disc from which a test piece is extracted.
    •  DESCRIPTION OF EMBODIMENTS Problem to be Solved by the Present Disclosure
  • Conventional molybdenum materials have not been able to obtain large volumes. The present invention has been made to solve the above problem.
    • Description of Embodiments of the Present Invention (1) Summary of Embodiments
  • A molybdenum material according to one embodiment of the present invention is a molybdenum material having a diameter of 75 mm or more and a length of 250 mm or more, and having a relative density of 99.5% or more.
  • Preferably, the molybdenum material has a relative density of 99.9% or more.
  • In one embodiment of the present invention, the molybdenum material contains 99.9% by mass or more of molybdenum.
  • In one embodiment of the present invention, the molybdenum material contains 0.3% by mass or more and 1.5% by mass or less of titanium, 0.03% by mass or more and 0.1% by mass or less of zirconium, and 0.01% by mass or more and 0.3% by mass or less of carbon, with a balance composed of molybdenum and unavoidable impurity.
  • A method for manufacturing a molybdenum material preferably comprises: (1) preparing a first core alloy having an outer diameter of 40 mm or less by hot isostatic pressing; (2) disposing the first core alloy in a tube having a diameter larger than that of the first core alloy; (3) disposing molybdenum powder in the tube around the first core alloy and subsequently compressing the tube by hot isostatic pressing; (4) removing the compressed tube to form a second core alloy having a diameter larger than that of the first core alloy; and repeating the steps (2) to (4).
    • (2) Comparison with Prior Art
  • According to PTL 1, in an example, W powder having a particle size of 4.1 μm was pressed with a pressure of 200 MPa by CIP (Cold Isostatic Pressing) and sintered in a hydrogen atmosphere having a temperature of 2250° C. to obtain a sintered rod having a relative density of 92%. In a subsequent step, the sintered rod was pressed by HIP (Hot Isostatic Pressing) at a temperature of 1750° C. and a pressure of 195 MPa for 3 hours to obtain a sintered rod having a relative density of 97.9%. A radial forging machine is used to form the rod with a forming degree of 67% to obtain a tungsten rod having an overall average relative density of 99.66% and having a relative core density of 99.63%. After the rod is annealed at a temperature of 1800° C. for 4 hours, it provides a crystal grain size, that is, about 800 crystal grains on average per square millimeter at a center portion of the rod and about 850 crystal grains on average per square millimeter at peripheral portion of the rod.
  • According to PTL 2, in an example, Mo powder having an average particle size of 45 μm or less is introduced into a soft steel can, and subsequently, the soft steel can is heated at 400° C. and vacuum-degassed, and thus sealed. The soft steel can was pressed by HIP at a temperature of 1250° C. and a pressure of 148 MPa for 5 hours to provide a Mo sintered body having a relative density of 99.8%. The Mo sintered body is cut to provide a plate having a length of 380 mm, a width of 110 mm, and a thickness of 8.1 mm, and the plate is heated to 700° C. and subsequently subjected to plastic working by rolling in a temperature range of 200° C. or higher to obtain a thickness of 4.6 mm.
  • The methods described in PTLs 1 and 2 do not meet customers' demand for efficient production of Mo material. In addition, the methods cannot produce a large-volume Mo material with little unevenness in density, that is required to meet demands for components such as furnace materials to have large size and high strength.
  • When a Mo material is manufactured through powder metallurgy, e.g., by pressing followed by sintering, or pressing by HIP, or the like, the resulting, sintered alloy tends to have an inner portion having a lower density and a peripheral portion having a higher density. This unevenness in density between the inner portion and the peripheral portion increases as the product's size increases. When the unevenness in density is corrected by plastic working involving a large amount of deformation, a large stress must be applied to the Mo material by hot working.
  • For the above reasons, increasing the diameter of a Mo material requires employing a large-sized preheating furnace and a large-sized hot plastic working apparatus. In addition, if the Mo material is not quickly transported from the non-oxidizing atmosphere in the preheating furnace to the air atmosphere in which the plastic working apparatus is disposed, the Mo material's temperature is reduced, and the Mo material cracks during plastic working. However, as the facilities are increased in size, and the Mo material is also increased in size and hence weight, it is difficult to quickly transport the Mo material.
  • In the present disclosure, as indicated in an embodiment by way of example, a Mo sintered body can be produced in a stepwise manner from a center side toward a peripheral side to have an overall high density to obtain a rod-shaped Mo material having a diameter of 75 mm or more which has not conventionally been achieved. By using the Mo material, a large number of components having uniform density can be obtained. When the Mo material is used for a target, the Mo material, having a uniform density, allows a large number of wafers which are uniformly consumed and thus have good consumability to be obtained. When the Mo material is used for a heater, the Mo material allows a large number of heating elements with small variation in electrical resistance and less likely to break to be obtained. When the Mo material is used for a furnace material, the Mo material allows a large number of members having uniform material strength to be obtained. When the Mo material is used for an electrode for resistance welding, the Mo material, having a uniform density, allows a large number of electrodes with small variation in bonding conditions to be obtained.
    • (3) Dimension of Mo Material
  • The Mo material has a diameter of 75 mm or more. The Mo material preferably has a diameter of 300 mm or less. When the Mo material has a diameter of 75 mm or more, the Mo material can be used for a large-volume component, for example, the aforementioned target, heater, furnace material, or electrode for resistance welding. Preferably, the Mo material has a diameter of 140 mm or more. More preferably, the Mo material has a diameter of 200 mm or more.
  • While the Mo material may have any diameter equal to or larger than 75 mm, it is preferably 300 mm or less from the viewpoint of actual use. The diameter of the Mo material is measured in a method as follows: the Mo material have a plurality of any portions thereof measured in diameter with a caliper, and an average value of maximum and minimum diameters measured is defined as the diameter of the Mo material.
  • Variation in diameter of the Mo material is preferably 20% or less. When the Mo material has a variation in diameter exceeding 20%, and a black skin formed on a periphery of the Mo material is removed by machining, it could be difficult to remove the black skin. It should be noted that the word “could” is intended to mean that there is a slight possibility that something will happen, and is not intended to mean that there is a high probability that it will happen.
  • The Mo material is not limited in shape to a cylindrical shape, and may have a polygonal shape. When the Mo material has a polygonal shape, the diameter of an imaginary circle having a maximum area inside the polygonal shape is defined as the diameter of the Mo material.
  • Further, the Mo material is measured in density at a portion inside the imaginary circle having the maximum area. The Mo material has a length of 250 mm or more. The Mo material preferably has a length of 1500 mm or less. When the Mo material has a length of 250 mm or more, and, for example, the aforementioned components are formed of the Mo material, a large number of such components can be obtained from the Mo material at a time. When the Mo material has a length of less than 250 mm, it could provide a small yield of such components and hence poor production efficiency. Further, without using a process in the present embodiment, a conventional process can also enhance the density of a center portion of the Mo material. While the Mo material may have any length equal to or larger than 250 mm, it is preferably 1500 mm or less from the viewpoint of actual use.
  • The Mo material internally has a relative density of 99.5% or more. When the Mo material internally has a relative density of 99.5% or more, and a large number of the aforementioned components are obtained from each portion of the Mo material, the components can have a small difference in density. Preferably, Mo material internally has a relative density of 99.9% or more. More preferably, the Mo material internally has a relative density of 100%.
  • When the Mo material internally has a relative density of less than 99.5%, it could provide components with a large unevenness in density therebetween, and hence variation in characteristics as components.
  • The Mo material's internal relative density is measured in the following method. Note that in the following description, the Mo material's relative density may simply be referred to as relative density. A disc having a thickness of 30 mm is cut out of the obtained rod-shaped Mo material at its opposite ends and center portion in its longitudinal direction for a total of three locations. As locations for evaluation, a total of three portions of each disc cut out, i.e., a portion in a vicinity of a surface, a center, and an intermediate portion between the vicinity of the surface and the center in the radial direction of the disc, are selected, and a test piece of 10×10×10 mm is cut out therefrom and subjected to measurement in relative density of the Mo material in Archimedes' method. Specifically, the Mo material's relative density is calculated from the composition of the Mo material, a theoretical density calculated from the composition of the Mo material, the volume of the test piece, and the mass of the test piece. The volume of the test piece is a volume corresponding to an increase of water in level in a beaker when the test piece is put in the beaker for the sake of illustration. The mass of the test piece is measured with an electronic balance.
  • The Mo material's relative density is determined by the following equation:

  • Mo material's relative density=(mass of test piece/volume of test piece)/theoretical density
  • The theoretical density is determined by the composition of the Mo material.
  • The Mo material may contain 99.9% by mass or more of Mo. When this Mo material is compared with a Mo material having a Mo content of less than 99.9% by mass, the former has better machinability and plastic workability than the latter.
  • The Mo material may contain 0.3% by mass or more and 1.5% by mass or less of Ti, 0.03% by mass or more and 0.1% by mass or less of Zr, and 0.01% by mass or more and 0.3% by mass or less of C, with a balance composed of Mo, unavoidable impurity and unavoidable gaseous impurity. When this Mo material is compared with the Mo material having a Mo content of 99.9% by mass or more, the former can have higher mechanical strength than the latter.
  • The unavoidable impurity for example includes at least one of Al, Ca, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sn, Si, Na, K and W. The unavoidable gaseous impurity for example includes at least one of N and O. The Mo material preferably contains 0.1% by mass or less of unavoidable impurity in a total amount. The Mo material preferably contains 0.01% by mass or less of unavoidable gaseous impurity in a total amount.
  • When the Mo material has a Ti content in mass exceeding 1.5% by mass, the Mo material could fail to have a sufficient density. When the Mo material has a Ti content in mass of less than 0.3% by mass, the Mo material could fail to have a strength exceeding that of pure Mo. Note that pure Mo is a material of molybdenum having a Mo content in mass of 99.9% by mass or more.
  • When the Mo material has a Zr content in mass exceeding 0.1% by mass, the Mo material could fail to have a sufficient density. When the Mo material has a Zr content in mass of less than 0.03% by mass, the Mo material could fail to have a strength exceeding that of pure Mo.
  • When the Mo material has a C content in mass exceeding 0.3% by mass, the Mo material could fail to have a sufficient density. When the Mo material has a C content in mass of less than 0.01% by mass, the Mo material could fail to have a strength exceeding that of pure Mo.
  • When the Mo material contains unavoidable impurity in a total amount exceeding 0.1% by mass, the Mo material could fail to have a sufficient density and stable characteristics. When the Mo material contains unavoidable gaseous impurity exceeding 0.01% by mass in a total amount, the Mo material could fail to have a sufficient density and stable characteristics.
  • The composition of metal elements is measured through ICP (Inductively Coupled Plasma Emission Spectroscopy) according to JIS H1404 (2001). ICPS-8100 manufactured by Shimadzu Corporation is used to measure metal elements through ICP. C is measured with EMIA-920-V2 manufactured by HORIBA, Ltd. O and N are measured with ON-836 manufactured by LECO JAPAN CORPORATION.
  • The Mo material preferably has a tensile strength of 400 MPa or more at room temperature and a tensile strength of 50 MPa or more at 1000° C. When the Mo material does not satisfy these tensile strengths, and for example it is used for a furnace material, the Mo material could be deformed in use.
  • The Mo material preferably includes, per square centimeter, no pore having a diameter of 30 μm or more and 200 or less pores having a diameter of less than 30 μm.
  • The number of pores included in the Mo material is counted in the following method. A disc-shaped sample having a thickness of 15 mm and a diameter of 10 mm is cut out of the obtained rod-shaped Mo material at the center and in a vicinity of a surface in the radial direction. Each sample has a cut surface polished to have a polished surface with a surface roughness (Rz) of 0.2 μm or less. The sample is polished for example as follows: the cut surface is polished with a waterproof paper of #180 to 2000 and subsequently buff-polished using a suspension of diamond having a particle size of 1 to 3 μm.
  • The sample's polished surface is observed with a stereomicroscope SZ40 manufactured by Olympus Corporation, and where a pore having a maximum diameter is located is confirmed. A range extracted from the polished surface of the sample including the location of the pore having the maximum diameter is observed at a magnification of 1000 times with a microscope VHX-6000 manufactured by Keyence Corporation to measure the maximum diameter of the pore. The maximum diameter of the pore is defined as the diameter of the inscribed circle of the observed pore. For the sake of illustration, the extracted range is within a circle having a radius of 4 mm from the center of the polished surface of the sample having a diameter of 10 mm. Further, the extracted range is enlarged by 100 times, and what has a different matrix and a different contrast is all determined as void and extracted, and subjected to contamination analysis to count the number of pores. In doing so, the number of pores is counted with an extraction parameter adjusted so that the pore's maximum diameter matches a measured value thereof as observed at the magnification of 1000 times.
  • When the Mo material includes, per square centimeter, pores having a diameter of 30 μm or more and more than 200 pores having a diameter of less than 30 μm, and the Mo material is used for example for a target, a film formed by sputtering could have large variation in thickness.
    • Detailed Description of Embodiments of the Present Invention
  • Hereinafter, the present invention will be described based on examples.
    • Example 1
  • (1) Process for Manufacturing Mo Sintered Body which is Mo Material
  • (1-1) Raw Material
  • As a raw material, Mo powder having an Fsss value of 4.0 μm as measured in the Fisher method was used. The Fsss value is preferably 3 μm or more and 10 μm or less. An Fsss value exceeding 10 μm could result in a Mo sintered body failing to have an overall increased density. An Fsss value of less than 3 μm could result in a Mo sintered body failing to have a center portion with an increased density. Pure Mo powder was used as raw material powder.
  • (1-2) Core Alloy
  • In Example 1, Mo materials of Sample Nos. 1 to 3 and 101 shown in Table 1 were produced.
  • TABLE 1
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm) relative density (%)
    final diameter: 75 mm sintered core 1st time 2nd time front end 1
    sample body size (mm) capsule's capsule's loc. loc. loc.
    no. diam. length inner diam. diam. length inner diam. diam. length 4 5 6
    ex. 1 1 20 1500 80 50 1500 102 75 1500 100 100 100
    2 30 1500 90 60 1500 95 75 1500 100 100 99.9
    3 40 1500 100 70 1500 88 75 1500 100 100 99.5
    comp. ex. 101 75 1500 100 100 99.1
    sintered body's relative density (%)
    final diameter: 75 mm center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6
    ex. 1 1 100 100 100 100 100 100
    2 100 100 100 100 100 99.9
    3 100 100 99.5 100 100 99.6
    comp. ex. 101 100 100 99 100 100 99.1
  • In order to obtain the sintered core bodies of Sample Nos. 1 to 3 and 101 shown in Table 1, four capsules 21 each being a tube shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 1, 60 mm for sample No. 2, 77 mm for sample No. 3, and 135 mm for sample No. 101. Capsule 21 is a soft steel can. Note, however, that capsule 21 is not limited in material to soft steel.
  • After raw material powder of Mo 10 is introduced into capsule 21 to have a bulk density of 4.2 g/cm3, a lid 22 having a hot-degassing pipe 23 welded thereto was welded to capsule 21 using TIG (Tungsten Inert Gas). A hose connected to an oil rotary pump and an oil diffusion pump was attached to a tip 25 of pipe 23.
  • A container with capsule 21 having lid 22 welded thereto was placed in an atmospheric furnace held at a temperature of 500° C. and vacuumed using the oil rotary pump and the oil diffusion pump so that the container had an internal pressure reduced from normal atmospheric pressure to 1×10−3 Pa. The container thus hot-degassed was extracted and had pipe 23 collapsed at a position to be provided with a seal portion 24, and cut off at the collapsed portion, and the cut pipe had an end TIG-welded and thus sealed to have seal portion 24.
  • The soft steel can preferably has a thickness of 3 mm or more and 20 mm or less. When the soft steel can has a thickness exceeding 20 mm, and pressure-sintered, the resulting Mo alloy could fail to have an increased density. When the soft steel can has a thickness of less than 3 mm, and pressure-sintered, capsule 21 could be broken. Capsule 21 may have a circumference and a bottom formed integrally, and when capsule 21 has a large size, the capsule may have a circumference and a bottom that are separate members TIG-welded and thus bonded together. Lid 22 can for example be a plate material having the same thickness as capsule 21.
  • In hot-degassing the container, the furnace preferably has an internal temperature of 400° C. or higher and 500° C. or lower. When the furnace's temperature exceeds 500° C., and the container internally has a low degree of vacuum, the Mo powder could be oxidized. When the furnace's temperature is lower than 400° C., a gas component or the like adsorbed on the Mo powder could be insufficiently degassed, and the Mo alloy may have pores therein.
  • The container is hot-degassed preferably for 1 hour or more and 5 hours or less after capsule 21 attains the same temperature as that of the interior of the furnace. Once a period of time for which the container is hot-degassed exceeds 5 hours, the Mo alloy no longer has its characteristics improved, and hot-degassing the container for a period of time exceeding 5 hours thus results in impaired economy. When the container is hot-degassed for less than 1 hour, a gas component or the like adsorbed on the Mo powder could be insufficiently degassed, and the Mo alloy may have pores therein.
  • When the container is hot-degassed, its internal ultimate pressure is preferably less than 1×10−2 Pa. When the container's internal ultimate pressure is 1×10−2 Pa or more, the container could be insufficiently degassed, and when it is HIPed, the Mo alloy's density could be less likely to increase.
  • The Mo powder in the container preferably has a bulk density of 2.5 g/cm3 or more and 5.0 g/cm3 or less. When the Mo powder has a bulk density exceeding 5.0 g/cm3, a gas component or the like adsorbed on the Mo powder could be insufficiently degassed, and the Mo alloy's density could be less likely to increase. When the Mo powder has a bulk density of less than 2.5 g/cm3, and is HIPed, the Mo alloy's shrinkability is excessively large, and a resulting Mo sintered body could fail to have a targeted shape. More preferably, the Mo powder in the container has a bulk density of 3.5 g/cm3 or more and 4.5 g/cm3 or less.
  • (1-3) Sintering
  • The sealed container was placed in a furnace of a hot isostatic pressing apparatus and subjected to pressure-sintering by HIP at a temperature of 1280° C. and a pressure of 147 MPa for 5 hours. Hereinafter, pressure-sintering by HIP may simply be referred to as HIP. As shown in FIG. 2, the container had an internal volume reduced by HIP.
  • After the container was pressure-sintered, the container was removed by machining to obtain a sintered core body 11, as shown in FIG. 3, as a first core alloy for Sample Nos. 1 to 3 and 101. Sintered core body 11 is sized as shown in Table 1.
  • Sintered core body 11 had its relative density measured in Archimedes' method, and it had a relative density of 99.5% or more and 99.9% or less at a center portion in the radial direction and a relative density of 100% at a portion other than the center portion. The HIP is performed with a heating temperature preferably of 1000° C. or higher and 1350° C. or lower. When the heating temperature exceeds 1350° C., it is a temperature close to the melting point of the soft steel constituting capsule 21, and capsule 21 could be broken during the HIP. When the heating temperature is lower than 1000° C., the Mo alloy's density could fail to increase during the HIP.
  • In the HIP, the container's internal ultimate pressure is preferably 98 MPa or more and 250 MPa or less. Once the container's internal ultimate pressure exceeds 250 MPa, the Mo alloy's density no longer increases, and HIPing the container beyond 250 MPa results in impaired economy. When the container's internal ultimate pressure is less than 98 MPa, the Mo alloy's density could fail to increase. The HIP is applied preferably for 1 hour or more and 10 hours or less. Applying the HIP beyond 10 hours does not further increase the Mo alloy's density, and HIPing the container beyond 10 hours results in impaired economy. When the HIP is applied for less than 1 hour, the Mo alloy's density could fail to increase.
  • When removing the soft steel can of the container, the Mo alloy's machining margin is preferably 3 mm or more and 10 mm or less. When the Mo alloy's machining margin exceeds 10 mm it results in an increased processing time and a reduced yield of material, and hence impaired economy. When the Mo alloy's machining margin is less than 3 mm, the soft steel can could be incompletely removed from the Mo alloy.
  • (1-4) Increasing Diameter
  • In order to increase the diameters of sintered core bodies 11 of Sample Nos. 1 to 3 in Table 1, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 1600 mm. Capsules 21 had inner diameters of 80 mm for sample No. 1, 90 mm for sample No. 2, and 100 mm for sample No. 3. Sintered core body 11 was disposed at the center of capsule 21, and the raw material described in the “(1-1) raw material” section was introduced between capsule 21 and sintered core body 11. Through the process described in the “(1-2) core alloy” section, the container was hot-degassed at a temperature of 400° C. and sealed.
  • Subsequently, pressure-sintering by HIP was performed as described in the “(1-3) Sintering” section, and thereafter the container was removed by machining. Thus, Mo sintered bodies as second core alloys of Sample Nos. 1 to 3 having diameters and lengths as indicated in Table 1 at the “1st time” column were obtained.
  • In order to further increase the diameters of the obtained Mo sintered bodies, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 1600 mm. Capsules 21 had inner diameters of 102 mm for sample No. 1, 95 mm for sample No. 2, and 88 mm for sample No. 3. Each Mo sintered body was disposed at the center of capsule 21, and the raw material described in the “(1-1) raw material” section was introduced between capsule 21 and sintered core body 11. Through the process described in the “(1-2) core alloy” section, the container was hot-degassed at a temperature of 400° C. and sealed.
  • Subsequently, pressure-sintering by HIP was performed as described in the “(1-3) Sintering” section, and thereafter the container was removed by machining. Thus, Mo sintered bodies as Mo materials of Sample Nos. 1 to 3 having diameters and lengths as indicated in Table 1 at the “2nd time” column were obtained.
  • (2) Evaluation of Mo Material
  • The rod-shaped Mo materials of Sample Nos. 1 to 3 and 101 having a diameter of 75 mm and a length of 1500 mm, as obtained through the above process, were each cut at a front end 1, a center 2 at a rear end 3, as shown in FIG. 4, to provide a disc having a thickness L1 of 30 mm. As shown in FIG. 5, test pieces were cut out of each disc at locations for evaluation, that is, as seen in the radial direction of the disc, a location 4 at the circumference, a location 6 at the center, and a location 5 between the circumference and the center, and subjected to measurement of relative density. A result thereof is shown in Table 1.
  • As shown in Table 1, it has been confirmed that the Mo materials of Sample Nos. 1 to 3 of Example 1 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 1 and 2 of Example 1 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 101 as a Comparative Example had a relative density including a portion less than 99.5%.
    • Example 2
  • In Example 2, sintered core body 11 was produced in the same manner as in Example 1 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed twice to have an increased diameter to thus produce Mo materials for Sample Nos. 4 to 6. For a comparative example, a Mo material for Sample No. 102 was produced in the same manner as Sample No. 101 except that the length was 1000 mm. In the same manner as in Example 1, test pieces were cutout and subjected to measurement of relative density. A result thereof is shown in Table 2.
  • TABLE 2
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm) relative density (%)
    final diameter: 75 mm sintered core 1st time 2nd time front end 1
    sample body size (mm) capsule's capsule's loc. loc. loc.
    no. diam. length inner diam. diam. length inner diam. diam. length 4 5 6
    ex. 2 4 20 1000 80 50 1000 102 75 1000 100 100 100
    5 30 1000 90 60 1000 95 75 1000 100 100 99.9
    6 40 1000 100 70 1000 88 75 1000 100 100 99.6
    comp. ex. 102 75 1000 100 100 99.2
    sintered body's relative density (%)
    final diameter: 75 mm center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6
    ex. 2 4 100 100 100 100 100 100
    5 100 100 100 100 100 100
    6 100 100 99.5 100 100 99.6
    comp. ex. 102 100 100 99 100 100 99.1
  • As shown in Table 2, it has been confirmed that the Mo materials of Sample Nos. 4 to 6 of Example 2 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 4 and 5 of Example 2 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 102 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 3
  • In Example 3, sintered core body 11 was produced in the same manner as in Example 1 except that the length was 500 mm, and sintered core body 11 was additionally HIPed twice to have an increased diameter to thus produce Mo materials for Sample Nos. 7 to 9. For a comparative example, a Mo material for Sample No. 103 was produced in the same manner as Sample No. 101 except that the length was 500 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 3.
  • TABLE 3
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm) relative density (%)
    final diameter: 75 mm sintered core 1st time 2nd time front end 1
    sample body size (mm) capsule's capsule's loc. loc. loc.
    no. diam. length inner diam. diam. length inner diam. diam. length 4 5 6
    ex. 3 7 20 500 80 50 500 102 75 500 100 100 100
    8 30 500 90 60 500 95 75 500 100 100 100
    9 40 500 100 70 500 88 75 500 100 100 99.5
    comp. ex. 103 75 500 100 100 99
    sintered body's relative density (%)
    final diameter: 75 mm center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6
    ex. 3 7 100 100 100 100 100 100
    8 100 100 100 100 100 99.9
    9 100 100 99.7 100 100 99.6
    comp. ex. 103 100 100 99 100 100 99.1
  • As shown in Table 3, it has been confirmed that the Mo materials of Sample Nos. 7 to 9 of Example 3 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 7 and 8 of Example 3 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 103 as the Comparative Example had a relative density including a portion less than 99.5%. [0069] (Example 4) In Example 4, sintered core body 11 was produced in the same manner as in Example 1 except that the length was 250 mm, and sintered core body 11 was additionally HIPed twice to have an increased diameter to thus produce Mo materials for Sample Nos. 10 to 12. For a comparative example, a Mo material for Sample No. 104 was produced in the same manner as Sample No. 101 except that the length was 250 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 4.
  • TABLE 4
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm) relative density (%)
    final diameter: 75 mm sintered core 1st time 2nd time front end 1
    sample body size (mm) capsule's capsule's loc. loc. loc.
    no. diam. length inner diam. diam. length inner diam. diam. length 4 5 6
    ex. 4 10 20 250 80 50 250 102 75 250 100 100 100
    11 30 250 90 60 250 95 75 250 100 100 100
    12 40 250 100 70 250 88 75 250 100 100 99.5
    comp. ex. 104 75 250 100 100 99
    sintered body's relative density (%)
    final diameter: 75 mm center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6
    ex. 4 10 100 100 100 100 100 100
    11 100 100 99.9 100 100 99.9
    12 100 100 99.5 100 100 99.6
    comp. ex. 104 100 100 99.2 100 100 99.1
  • As shown in Table 4, it has been confirmed that the Mo materials of Sample Nos. 10 to 12 of Example 4 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 10 and 11 of Example 4 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 104 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 5
  • In Example 5, in order to obtain sintered core bodies 11 for Sample Nos. 13 to 15, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 13, 60 mm for sample No. 14, and 77 mm for sample No. 15. Sintered core body 11 was produced in the same manner as in Example 1, and additionally HIPed twice or three times to have an increased diameter of 100 mm to thus produce Mo materials for Sample Nos. 13 to 15. For a comparative example, a Mo material for Sample No. 105 was produced in the same manner as Sample No. 101 except that the diameter was 100 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 5.
  • TABLE 5
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm)
    final diameter: 100 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's loc. loc. loc.
    no. diam. length inner diam. diam. length inner diam. diam. length 4 5 6
    ex. 5 13 20 1500 80 50 1500 110 80 1500 123 100 1500
    14 30 1500 90 60 1500 120 90 1500 117 100 1500
    15 40 1500 100 70 1500 130 100 1500
    comp. ex. 105 100 1500
    sintered body's relative density (%)
    final diameter: 100 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 5 13 100 100 100 100 100 100 100 100 100
    14 100 99.9 100 100 100 100 100 100 99.9
    15 100 99.9 99.6 100 100 99.5 100 100 99.7
    comp. ex. 105 100 100 99.1 100 100 99.1 100 100 99.1
  • As shown in Table 5, it has been confirmed that the Mo materials of Sample Nos. 13 to 15 of Example 5 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 13 and 14 of Example 5 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 105 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 6
  • In Example 6, sintered core body 11 was produced in the same manner as in Example 5 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed twice or three times to have an increased diameter to thus produce Mo materials for Sample Nos. 16 to 18. For a comparative example, a Mo material for Sample No. 106 was produced in the same manner as Sample No. 105 except that the length was 1000 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 6.
  • TABLE 6
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm)
    final diameter: 100 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 6 16 20 1000 80 50 1000 110 80 1000 123 100 1000
    17 30 1000 90 60 1000 120 90 1000 117 100 1000
    18 40 1000 100 70 1000 130 100 1000
    comp. ex. 106 100 1000
    sintered body's relative density (%)
    final diameter: 100 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 6 16 100 100 100 100 100 100 100 100 100
    17 100 100 99.9 100 100 99.9 100 100 100
    18 100 99.9 99.5 100 100 99.7 100 100 99.7
    comp. ex. 106 100 100 99.1 100 100 99.1 100 100 99.2
  • As shown in Table 6, it has been confirmed that the Mo materials of Sample Nos. 16 to 18 of Example 6 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 16 and 17 of Example 6 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 106 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 7
  • In Example 7, sintered core body 11 was produced in the same manner as in Example 5 except that the length was 500 mm, and sintered core body 11 was additionally HIPed twice or three times to have an increased diameter to thus produce Mo materials for Sample Nos. 19 to 21. For a comparative example, a Mo material for Sample No. 107 was produced in the same manner as Sample No. 105 except that the length was 500 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 7.
  • TABLE 7
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm)
    final diameter: 100 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 7 19 20 500 80 50 500 110 80 500 123 100 500
    20 30 500 90 60 500 120 90 500 117 100 500
    21 40 500 100 70 500 130 100 500
    comp. ex. 107 100 500
    sintered body's relative density (%)
    final diameter: 100 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 7 19 100 100 100 100 100 100 100 100 100
    20 100 100 100 100 100 99.9 100 100 100
    21 100 100 99.5 100 100 99.6 100 100 99.7
    comp. ex. 107 100 100 99.2 100 100 99.1 100 100 99.2
  • As shown in Table 7, it has been confirmed that the Mo materials of Sample Nos. 19 to 21 of Example 7 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 19 and 20 of Example 7 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 107 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 8
  • In Example 8, sintered core body 11 was produced in the same manner as in Example 5 except that the length was 250 mm, and sintered core body 11 was additionally HIPed twice or three times to have an increased diameter to thus produce Mo materials for Sample Nos. 22 to 24. For a comparative example, a Mo material for Sample No. 108 was produced in the same manner as Sample No. 105 except that the length was 250 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 8.
  • TABLE 8
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm)
    final diameter: 100 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 8 22 20 250 80 50 250 110 80 250 123 100 250
    23 30 250 90 60 250 120 90 250 117 100 250
    24 40 250 100 70 250 130 100 250
    comp. ex. 108 100 250
    sintered body's relative density (%)
    final diameter: 100 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 8 22 100 100 100 100 100 100 100 100 100
    23 100 100 100 100 100 99.9 100 100 99.9
    24 100 100 99.5 100 99.9 99.6 100 99.9 99.7
    comp. ex. 108 100 100 99.2 100 100 99.1 100 100 99.1
  • As shown in Table 8, it has been confirmed that the Mo materials of Sample Nos. 22 to 24 of Example 8 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 22 and 23 of Example 8 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 108 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 9
  • In Example 9, in order to obtain sintered core bodies 11 for Sample Nos. 25 to 27, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 25, 60 mm for sample No. 26, and 77 mm for sample No. 27. Sintered core body 11 was produced in the same manner as in Example 1, and additionally HIPed four or five times to have an increased diameter of 150 mm to thus produce Mo materials for Sample Nos. 25 to 27. For a comparative example, a Mo material for Sample No. 109 was produced in the same manner as Sample No. 101 except that the diameter was 150 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 9 and 10.
  • TABLE 9
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm)
    final diameter: 150 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 9 25 20 1500 80 50 1500 110 80 1500 140 110 1500
    26 30 1500 90 60 1500 120 90 1500 150 120 1500
    27 40 1500 100 70 1500 130 100 1500 160 130 1500
    comp. ex. 109 150 1500
    capsule's inner diameter,
    sintered body's and diameter & length after additional HIP (mm)
    final diameter: 150 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 9 25 170 140 1500 167 150 1500
    26 180 150 1500
    27 173 150 1500
    comp. ex. 109
  • TABLE 10
    sintered body's relative density (%)
    final diameter: 150 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 9 25 100 100 100 100 100 100 100 100 100
    26 100 100 100 100 99.9 99.9 100 100 99.9
    27 100 100 99.5 100 99.9 99.6 100 100 99.6
    comp. ex. 109 100 100 99 100 100 99.1 100 100 99.2
  • As shown in Table 10, it has been confirmed that the Mo materials of Sample Nos. 25 to 27 of Example 9 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 25 and 26 of Example 9 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 109 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 10
  • In Example 10, sintered core body 11 was produced in the same manner as in Example 9 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed four or five times to have an increased diameter to thus produce Mo materials for Sample Nos. 28 to 30. For a comparative example, a Mo material for Sample No. 110 was produced in the same manner as Sample No. 109 except that the length was 1000 mm. In the same manner as in Example 1, test pieces were cutout and subjected to measurement of relative density. A result thereof is shown in Tables 11 and 12.
  • TABLE 11
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 150 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 10 28 20 1000 80 50 1000 110 80 1000 140 110 1000
    29 30 1000 90 60 1000 120 90 1000 150 120 1000
    30 40 1000 100 70 1000 130 100 1000 160 130 1000
    comp. ex. 110 150 1000
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 150 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 10 28 170 140 1000 167 150 1000
    29 180 150 1000
    30 173 150 1000
    comp. ex. 110
  • TABLE 12
    sintered body's relative density (%)
    final diameter: 150 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 10 28 100 100 100 100 100 100 100 100 100
    29 100 100 100 100 100 99.9 100 100 99.9
    30 100 100 99.5 100 100 99.6 100 100 99.5
    comp. ex. 110 100 100 99.2 100 100 99.1 100 100 99.2
  • As shown in Table 12, it has been confirmed that the Mo materials of Sample Nos. 28 to 30 of Example 10 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 28 and 29 of Example 10 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 110 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 11
  • In Example 11, sintered core body 11 was produced in the same manner as in Example 9 except that the length was 500 mm, and sintered core body 11 was additionally HIPed four or five times to have an increased diameter to thus produce Mo materials for Sample Nos. 31 to 33. For a comparative example, a Mo material for Sample No. 111 was produced in the same manner as Sample No. 109 except that the length was 500 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 13 and 14.
  • TABLE 13
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 150 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 11 31 20 500 80 50 500 110 80 500 140 110 500
    32 30 500 90 60 500 120 90 500 150 120 500
    33 40 500 100 70 500 130 100 500 160 130 500
    comp. ex. 111 150 500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 150 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 11 31 170 140 500 167 150 500
    32 180 150 500
    33 173 150 500
    comp. ex. 111
  • TABLE 14
    sintered body's relative density (%)
    final diameter: 150 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 11 31 100 100 100 100 100 100 100 100 100
    32 100 100 100 100 100 99.9 100 100 100
    33 100 100 99.5 100 99.9 99.5 100 100 99.5
    comp. ex. 111 100 100 99.1 100 100 99.1 100 100 99.2
  • As shown in Table 14, it has been confirmed that the Mo materials of Sample Nos. 31 to 33 of Example 11 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 31 and 32 of Example 11 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 111 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 12
  • In Example 12, sintered core body 11 was produced in the same manner as in Example 9 except that the length was 250 mm, and sintered core body 11 and additionally HIPed four or five times to have an increased diameter to thus produce Mo materials for Sample Nos. 34 to 36. For a comparative example, a Mo material for Sample No. 112 was produced in the same manner as Sample No. 109 except that the length was 250 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 15 and 16.
  • TABLE 15
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 150 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 12 34 20 250 80 50 250 110 80 250 140 110 250
    35 30 250 90 60 250 120 90 250 150 120 250
    36 40 250 100 70 250 130 100 250 160 130 250
    comp. ex. 112 150 250
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 150 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 12 34 170 140 250 167 150 250
    35 180 150 250
    36 173 150 250
    comp. ex. 112
  • TABLE 16
    sintered body's relative density (%)
    final diameter: 150 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 12 34 100 100 100 100 100 100 100 100 100
    35 100 100 100 100 100 99.9 100 100 99.9
    36 100 99.9 99.5 100 99.9 99.5 100 100 99.5
    comp. ex. 112 100 99.9 99.2 100 100 99.1 100 99.9 99.2
  • As shown in Table 16, it has been confirmed that the Mo materials of Sample Nos. 34 to 36 of Example 12 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 34 and 35 of Example 12 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 112 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 13
  • In Example 13, in order to obtain sintered core bodies 11 for Sample Nos. 37 to 39, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 37, 60 mm for sample No. 38, and 77 mm for sample No. 39. Sintered core body 11 was produced in the same manner as in Example 1, and additionally HIPed six or seven times to have an increased diameter of 220 mm to thus produce Mo materials for Sample Nos. 37 to 39. For a comparative example, a Mo material for Sample No. 113 was produced in the same manner as Sample No. 101 except that the diameter was 220 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 17 and 18.
  • TABLE 17
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 220 mm sintered core 1st time 2nd time 3rd time 4th time
    sample body size (mm) capsule's capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length inner diam.
    ex. 13 37 20 1500 80 50 1500 110 80 1500 140 110 1500 170
    38 30 1500 90 60 1500 120 90 1500 150 120 1500 180
    39 40 1500 100 70 1500 130 100 1500 160 130 1500 190
    comp. ex. 113 220 1500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 220 mm 5th time 6th time 7th time
    sample 4th time capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 13 37 140 1500 200 170 1500 230 200 1500 243 220 1500
    38 150 1500 210 180 1500 240 210 1500 237 220 1500
    39 160 1500 220 190 1500 250 220 1500
    comp. ex. 113
  • TABLE 18
    sintered body's relative density (%)
    final diameter: 220 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 13 37 100 100 100 100 100 100 100 100 100
    38 100 100 100 100 100 100 100 100 99.9
    39 100 99.9 99.6 100 99.9 99.7 100 100 99.5
    comp. ex. 113 100 99.9 99 100 99.8 99.1 100 100 99.2
  • As shown in Table 18, it has been confirmed that the Mo materials of Sample Nos. 37 to 39 of Example 13 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 37 and 38 of Example 13 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 113 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 14
  • In Example 14, sintered core body 11 was produced in the same manner as in Example 13 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed six or seven times to have an increased diameter to thus produce Mo materials for Sample Nos. 40 to 42. For a comparative example, a Mo material for Sample No. 110 was produced in the same manner as Sample No. 113 except that the length was 1000 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 19 and 20.
  • TABLE 19
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 220 mm sintered core 1st time 2nd time 3rd time 4th time
    sample body size (mm) capsule's capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length inner diam.
    ex. 14 40 20 1000 80 50 1000 110 80 1000 140 110 1000 170
    41 30 1000 90 60 1000 120 90 1000 150 120 1000 180
    42 40 1000 100 70 1000 130 100 1000 160 130 1000 190
    comp. ex. 114 220 1000
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 220 mm 5th time 6th time 7th time
    sample 4th time capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 14 40 140 1000 200 170 1000 230 200 1000 243 220 1000
    41 150 1000 210 180 1000 240 210 1000 237 220 1000
    42 160 1000 220 190 1000 250 220 1000
    comp. ex. 114
  • TABLE 20
    sintered body's relative density (%)
    final diameter: 220 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 14 40 100 100 100 100 100 100 100 100 100
    41 100 100 99.9 100 100 99.9 100 100 99.9
    42 100 100 99.5 100 100 99.7 100 99.9 99.5
    comp. ex. 114 100 99.9 98.9 100 99.8 99 100 100 99.1
  • As shown in Table 20, it has been confirmed that the Mo materials of Sample Nos. 40 to 42 of Example 14 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 40 and 41 of Example 14 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 114 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 15
  • In Example 15, sintered core body 11 was produced in the same manner as in Example 13 except that the length was 500 mm, and sintered core body 11 was additionally HIPed six or seven times to have an increased diameter to thus produce Mo materials for Sample Nos. 43 to 45. For a comparative example, a Mo material for Sample No. 115 was produced in the same manner as Sample No. 113 except that the length was 500 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 21 and 22.
  • TABLE 21
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 220 mm sintered core 1st time 2nd time 3rd time 4th time
    sample body size (mm) capsule's capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length inner diam.
    ex. 15 43 20 500 80 50 500 110 80 500 140 110 500 170
    44 30 500 90 60 500 120 90 500 150 120 500 180
    45 40 500 100 70 500 130 100 500 160 130 500 190
    comp. ex. 115 220 500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 220 mm 5th time 6th time 7th time
    sample 4th time capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 15 43 140 500 200 170 500 230 200 500 243 220 500
    44 150 500 210 180 500 240 210 500 237 220 500
    45 160 500 220 190 500 250 220 500
    comp. ex. 115
  • TABLE 22
    sintered body's relative density (%)
    final diameter: 220 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 15 43 100 100 100 100 100 100 100 100 100
    44 100 100 99.9 100 100 100 100 100 99.9
    45 100 100 99.6 100 99.9 99.6 100 100 99.5
    comp. ex. 115 100 100 99 100 99.8 99.1 100 100 99.1
  • As shown in Table 22, it has been confirmed that the Mo materials of Sample Nos. 43 to 45 of Example 15 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 43 and 44 of Example 15 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 115 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 16
  • In Example 16, sintered core body 11 was produced in the same manner as in Example 13 except that the length was 250 mm, and sintered core body 11 was additionally HIPed six or seven times to have an increased diameter to thus produce Mo materials for Sample Nos. 46 to 48. For a comparative example, a Mo material for Sample No. 116 was produced in the same manner as Sample No. 113 except that the length was 250 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 23 and 24.
  • TABLE 23
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 220 mm sintered core 1st time 2nd time 3rd time 4th time
    sample body size (mm) capsule's capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length inner diam.
    ex. 16 46 20 250 80 50 250 110 80 250 140 110 250 170
    47 30 250 90 60 250 120 90 250 150 120 250 180
    48 40 250 100 70 250 130 100 250 160 130 250 190
    comp. ex. 116 220 250
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 220 mm 5th time 6th time 7th time
    sample 4th time capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 16 46 140 250 200 170 250 230 200 250 243 220 250
    47 150 250 210 180 250 240 210 250 237 220 250
    48 160 250 220 190 250 250 220 250
    comp. ex. 116
  • TABLE 24
    sintered body's relative density (%)
    final diameter: 220 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 16 46 100 100 100 100 100 100 100 100 100
    47 100 100 99.9 100 100 100 100 100 99.9
    48 100 100 99.6 100 99.9 99.7 100 99.9 99.5
    comp. ex. 116 100 100 99 100 99.9 99 100 100 99.2
  • As shown in Table 24, it has been confirmed that the Mo materials of Sample Nos. 46 to 48 of Example 16 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 47 and 48 of Example 16 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 116 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 17
  • In Example 17, in order to obtain sintered core bodies 11 for Sample Nos. 49 to 51, capsules 21 of three soft steel cans each shown in FIG. 1 were prepared. Capsule 21 had a thickness of 10 mm and a length of 2000 mm. Capsule 21 had inner diameters of 43 mm for sample No. 49, 60 mm for sample No. 50, and 77 mm for sample No. 51. Sintered core body 11 was produced in the same manner as in Example 1, and additionally HIPed nine or ten times to have an increased diameter of 300 mm to thus produce Mo materials for Sample Nos. 49 to 51. For a comparative example, a Mo material for Sample No. 117 was produced in the same manner as Sample No. 101 except that the diameter was 300 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 25 and 26.
  • TABLE 25
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 17 49 20 1500 80 50 1500 110 80 1500 140 110 1500
    50 30 1500 90 60 1500 120 90 1500 150 120 1500
    51 40 1500 100 70 1500 130 100 1500 160 130 1500
    comp. ex. 117 300 1500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 17 49 170 140 1500 200 170 1500
    50 180 150 1500 210 180 1500
    51 190 160 1500 220 190 1500
    comp. ex. 117
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 6th time 7th time 8th time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 17 49 20 1500 230 200 1500 260 230 1500 290 260 1500
    50 30 1500 240 210 1500 270 240 1500 300 270 1500
    51 40 1500 250 220 1500 280 250 1500 310 280 1500
    comp. ex. 117 300 1500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 9th time 10th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 17 49 320 290 1500 317 300 1500
    50 330 300 1500
    51 323 300 1500
    comp. ex. 117
  • TABLE 26
    sintered body's relative density (%)
    final diameter: 300 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 17 49 100 100 100 100 100 100 100 100 100
    50 100 100 99.9 100 100 100 100 100 100
    51 100 100 99.6 100 99.9 99.6 100 100 99.6
    comp. ex. 117 100 99.9 99.1 100 99.9 99.1 100 99.9 99.2
  • As shown in Table 26, it has been confirmed that the Mo materials of Sample Nos. 49 to 51 of Example 17 had a relative density of 99.6% or more. It has been confirmed that the Mo materials of Sample Nos. 49 and 50 of Example 17 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 117 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 18
  • In Example 18, sintered core body 11 was produced in the same manner as in Example 17 except that the length was 1000 mm, and sintered core body 11 was additionally HIPed nine or ten times to have an increased diameter to thus produce Mo materials for Sample Nos. 52 to 54. For a comparative example, a Mo material for Sample No. 118 was produced in the same manner as Sample No. 117 except that the length was 1000 mm. In the same manner as in Example 1, test pieces were cutout and subjected to measurement of relative density. A result thereof is shown in Tables 27 and 28.
  • TABLE 27
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 18 52 20 1000 80 50 1000 110 80 1000 140 110 1000
    53 30 1000 90 60 1000 120 90 1000 150 120 1000
    54 40 1000 100 70 1000 130 100 1000 160 130 1000
    comp. ex. 118 300 1000
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 18 52 170 140 1000 200 170 1000
    53 180 150 1000 210 180 1000
    54 190 160 1000 220 190 1000
    comp. ex. 118
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 6th time 7th time 8th time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 18 52 20 1000 230 200 1000 260 230 1000 290 260 1000
    53 30 1000 240 210 1000 270 240 1000 300 270 1000
    54 40 1000 250 220 1000 280 250 1000 310 280 1000
    comp. ex. 118 300 1000
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 9th time 10th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 18 52 320 290 1000 317 300 1000
    53 330 300 1000
    54 323 300 1000
    comp. ex. 118
  • TABLE 28
    sintered body's relative density (%)
    final diameter: 300 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 18 52 100 100 100 100 100 100 100 100 100
    53 100 100 100 100 99.9 100 100 100 99.9
    54 100 99.8 99.5 100 100 99.6 100 99.9 99.6
    comp. ex. 118 100 99.9 99.2 100 100 99 100 99.9 99.3
  • As shown in Table 27, it has been confirmed that the Mo materials of Sample Nos. 52 to 54 of Example 18 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 52 and 53 of Example 18 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 118 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 19
  • In Example 19, sintered core body 11 was produced in the same manner as in Example 17 except that the length was 500 mm, and sintered core body 11 was additionally HIPed nine or ten times to have an increased diameter to thus produce Mo materials for Sample Nos. 55 to 57. For a comparative example, a Mo material for Sample No. 119 was produced in the same manner as Sample No. 117 except that the length was 500 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 29 and 30.
  • TABLE 29
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 19 55 20 500 80 50 500 110 80 500 140 110 500
    56 30 500 90 60 500 120 90 500 150 120 500
    57 40 500 100 70 500 130 100 500 160 130 500
    comp. ex. 119 300 500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 19 55 170 140 500 200 170 500
    56 180 150 500 210 180 500
    57 190 160 500 220 190 500
    comp. ex. 119
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 6th time 7th time 8th time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 19 55 20 500 230 200 500 260 230 500 290 260 500
    56 30 500 240 210 500 270 240 500 300 270 500
    57 40 500 250 220 500 280 250 500 310 280 500
    comp. ex. 119 300 500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 9th time 10th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 19 55 320 290 500 317 300 500
    56 330 300 500
    57 323 300 500
    comp. ex. 119
  • TABLE 30
    sintered body's relative density (%)
    final diameter: 300 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 19 55 100 100 100 100 100 100 100 100 100
    56 100 100 99.9 100 100 99.9 100 100 100
    57 100 99.9 99.7 100 100 99.7 100 100 99.5
    comp. ex. 119 100 99.9 99 100 100 99.1 100 100 99.2
  • As shown in Table 30, it has been confirmed that the Mo materials of Sample Nos. 55 to 57 of Example 19 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 55 and 56 of Example 19 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 119 as the Comparative Example had a relative density including a portion less than 99.5%.
    • Example 20
  • In Example 20, sintered core body 11 was produced in the same manner as in Example 17 except that the length was 250 mm, and sintered core body 11 was additionally HIPed nine or ten times to have an increased diameter to thus produce Mo materials for Sample Nos. 58 to 60. For a comparative example, a Mo material for Sample No. 120 was produced in the same manner as Sample No. 117 except that the length was 250 mm. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 31 and 32.
  • TABLE 31
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 20 58 20 250 80 50 250 110 80 250 140 110 250
    59 30 250 90 60 250 120 90 250 150 120 250
    60 40 250 100 70 250 130 100 250 160 130 250
    comp. ex. 120 300 250
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 20 58 170 140 250 200 170 250
    59 180 150 250 210 180 250
    60 190 160 250 220 190 250
    comp. ex. 120
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 6th time 7th time 8th time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 20 58 20 250 230 200 250 260 230 250 290 260 250
    59 30 250 240 210 250 270 240 250 300 270 250
    60 40 250 250 220 250 280 250 250 310 280 250
    comp. ex. 120 300 250
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 9th time 10th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 20 58 320 290 250 317 300 250
    59 330 300 250
    60 323 300 250
    comp. ex. 120
  • TABLE 32
    sintered body's relative density (%)
    final diameter: 300 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 20 58 100 100 100 100 100 100 100 100 100
    59 100 100 100 100 99.9 99.9 100 100 99.9
    60 100 99.9 99.6 100 99.9 997 100 100 99.5
    comp. ex. 120 100 99.8 99 100 99.8 99 100 100 99.1
  • As shown in Table 32, it has been confirmed that the Mo materials of Sample Nos. 58 to 60 of Example 20 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 58 and 59 of Example 20 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 120 as the Comparative Example had a relative density including a portion less than 99.5%.
  • From the results of Examples 1 to 20, it has been confirmed that, even when the Mo material contains 99.9% by mass or more of Mo, the Mo material can have a relative density of 99.5% or more, and furthermore, the Mo material can also have a relative density of 99.9% or more.
    • Example 21
  • In Example 21, Mo materials for Sample Nos. 301 to 303 and 601 were produced in the same manner as in Example 17 except that the Mo materials had a composition changed by adding a Ti component, a Zr component and a C component to a Mo component of a raw material. Specifically, Mo powder, TiC powder, and ZrC powder were mixed together to prepare raw material powder. The Mo powder had an Fsss value of 4.0 μm. The TiC powder had an Fsss value of 2.0 μm. The ZrC powder had an Fsss value of 3.0 μm.
  • The Mo powder preferably has an Fsss value of 3 μm or more and 10 μm or less. When the Mo powder has an Fsss value exceeding 10 μm, it could result in a Mo sintered body failing to have an overall increased density. When the Mo powder has an Fsss value of less than 3 μm, it could result in a Mo sintered body failing to have a center portion with an increased density. The TiC powder preferably has an Fsss value of 1 μm or more and 20 μm or less. When the TiC powder has an Fsss value exceeding 20 μm, it could result in a Mo sintered body failing to have an overall increased density. When the TiC powder has an Fsss value of less than 1 μm, it could result in a Mo sintered body failing to have a center portion with an increased density. The ZrC powder preferably has an Fsss value of 1 μm or more and 20 μm or less. When the ZrC powder has an Fsss value exceeding 20 μm, it could result in a Mo sintered body failing to have an overall increased density. When the ZrC powder has an Fsss value of less than 1 μm, it could result in a Mo sintered body failing to have a center portion with an increased density.
  • Instead of TiC powder, pure Ti powder or TiH powder may be mixed. Instead of ZrC powder, pure Zr powder or ZrH powder may be mixed. In these cases, C powder is mixed with raw material powder. C powder may also be mixed with raw material powder when TiC powder and ZrC powder are used. The C powder preferably has an Fsss value of 0.1 μm or more and 10 μm or less. When the C powder has an Fsss value exceeding 10 μm, it could result in a Mo sintered body failing to have an overall increased density. When the C powder has an Fsss value of less than 0.1 μm, it could result in a Mo sintered body failing to have a center portion with an increased density. Note that pure Ti is a titanium material having a Ti content in mass of 99.9% by mass or more. Note that pure Zr is a zirconium material having a Zr content in mass of 99.9% by mass or more.
  • Table 33 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 21. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 34 and 35.
  • TABLE 33
    ex. 21 comp. ex.
    sample no. 301 302 303 601
    weighed Mo 99.66 99.66 99.66 99.66
    value Ti 0.3 0.3 0.3 0.3
    (mass %) Zr 0.03 0.03 0.03 0.03
    C 0.01 0.01 0.01 0.01
    measured Mo 99.594 99.603 99.604 99.604
    value of Ti 0.310 0.300 0.300 0.300
    composition Zr 0.031 0.030 0.031 0.031
    (mass %) C 0.010 0.010 0.010 0.010
    unavoidable 0.050 0.051 0.050 0.005
    impurity
    unavoidable 0.005 0.006 0.005 0.005
    gaseous
    impurity
  • TABLE 34
    sintered body's sintered core capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm body 1st time 2nd time 3rd time
    sample size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 21 301 20 1500 80 50 1500 110 80 1500 140 110 1500
    302 30 1500 90 60 1500 120 90 1500 150 120 1500
    303 40 1500 100 70 1500 130 100 1500 160 130 1500
    comp. ex. 601 300 1500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 21 301 170 140 1500 200 170 1500
    302 180 150 1500 210 180 1500
    303 190 160 1500 220 190 1500
    comp. ex. 601
    sintered body's sintered core capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm body 6th time 7th time 8th time
    sample size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 21 301 20 1500 230 200 1500 260 230 1500 290 260 1500
    302 30 1500 240 210 1500 270 240 1500 300 270 1500
    303 40 1500 250 220 1500 280 250 1500 310 280 1500
    comp. ex. 601 300 1500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 9th time 10th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 21 301 320 290 1500 317 300 1500
    302 330 300 1500
    303 323 300 1500
    comp. ex. 601
  • TABLE 35
    sintered body's relative density (%)
    final diameter: 300 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 21 301 100 100 100 100 100 100 100 100 100
    302 100 99.9 100 99.9 100 100 100 99.9 99.9
    303 100 99.6 99.8 100 99.6 100 100 99.6 99.7
    comp. ex. 601 100 99.4 99.7 99.8 99.4 99.9 99.9 99.4 100
  • As shown in Table 35, it has been confirmed that the Mo materials of Sample Nos. 301 to 303 of Example 21 had a relative density of 99.6% or more. It has been confirmed that the Mo materials of Sample Nos. 301 and 302 of Example 21 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 601 as a Comparative Example had a relative density including a portion less than 99.5%.
    • Example 22
  • In Example 22, Mo materials for Sample Nos. 401 to 403 and 602 were produced in the same manner as in Example 21 except for the compositions of the Mo materials. Table 36 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 22. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 37 and 38.
  • TABLE 36
    ex. 22 comp. ex.
    sample no. 401 402 403 602
    weighed Mo 99.38 99.38 99.38 99.38
    value Ti 0.5 0.5 0.5 0.5
    (mass %) Zr 0.08 0.08 0.08 0.08
    C 0.04 0.04 0.04 0.04
    measured Mo 99.317 99.322 99.335 99.324
    value of Ti 0.510 0.500 0.490 0.500
    composition Zr 0.080 0.081 0.080 0.080
    (mass %) C 0.040 0.042 0.040 0.041
    unavoidable 0.049 0.050 0.050 0.049
    impurity
    unavoidable 0.004 0.005 0.005 0.006
    gaseous
    impurity
  • TABLE 37
    sintered body's sintered core capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm body 1st time 2nd time 3rd time
    sample size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 22 401 20 1500 80 50 1500 110 80 1500 140 110 1500
    402 30 1500 90 60 1500 120 90 1500 150 120 1500
    403 40 1500 100 70 1500 130 100 1500 160 130 1500
    comp. ex. 602 300 1500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 22 401 170 140 1500 200 170 1500
    402 180 150 1500 210 180 1500
    403 190 160 1500 220 190 1500
    comp. ex. 602
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 6th time 7th time 8th time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 22 401 20 1500 230 200 1500 260 230 1500 290 260 1500
    402 30 1500 240 210 1500 270 240 1500 300 270 1500
    403 40 1500 250 220 1500 280 250 1500 310 280 1500
    comp. ex. 602 300 1500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 9th time 10th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 22 401 320 290 1500 317 300 1500
    402 330 300 1500
    403 323 300 1500
    comp. ex. 602
  • TABLE 38
    sintered body's relative density (%)
    final diameter: 300 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 22 401 100 100 100 100 100 100 100 100 100
    402 99.9 99.9 99.9 99.9 99.8 100 99.9 99.9 99.9
    403 99.9 99.6 99.8 99.9 99.6 99.8 100 99.7 99.7
    comp. ex. 602 99.8 99.4 99.2 99.8 99.3 99.2 99.8 99.3 99.2
  • As shown in Table 38, it has been confirmed that the Mo materials of Sample Nos. 401 to 403 of Example 22 had a relative density of 99.6% or more. It has been confirmed that the Mo materials of Sample Nos. 401 and 402 of Example 22 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 602 as a Comparative Example had a relative density including a portion less than 99.5%.
    • Example 23
  • In Example 23, Mo materials for Sample Nos. 501 to 503 and 603 were produced in the same manner as in Example 21 except for the compositions of the Mo materials. Table 39 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 23. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Tables 40 and 41.
  • TABLE 39
    ex. 23 comp. ex.
    sample no. 501 502 503 603
    weighed Mo 98.10 98.10 98.10 98.10
    value Ti 1.5 1.5 1.5 1.5
    (mass %) Zr 0.10 0.10 0.10 0.10
    C 0.30 0.30 0.30 0.30
    measured Mo 98.076 98.055 98.075 98.044
    value of Ti 1.480 1.500 1.490 1.500
    composition Zr 0.100 0.090 0.100 0.100
    (mass %) C 0.290 0.300 0.280 0.300
    unavoidable 0.050 0.050 0.051 0.051
    impurity
    unavoidable 0.004 0.005 0.004 0.005
    gaseous
    impurity
  • TABLE 40
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 1st time 2nd time 3rd time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 23 501 20 1500 80 50 1500 110 80 1500 140 110 1500
    502 30 1500 90 60 1500 120 90 1500 150 120 1500
    503 40 1500 100 70 1500 130 100 1500 160 130 1500
    comp. ex. 603 300 1500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 4th time 5th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 23 501 170 140 1500 200 170 1500
    502 180 150 1500 210 180 1500
    503 190 160 1500 220 190 1500
    comp. ex. 603
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm sintered core 6th time 7th time 8th time
    sample body size (mm) capsule's capsule's capsule's
    no. diam. length inner diam. diam. length inner diam. diam. length inner diam. diam. length
    ex. 23 501 20 1500 230 200 1500 260 230 1500 290 260 1500
    502 30 1500 240 210 1500 270 240 1500 300 270 1500
    503 40 1500 250 220 1500 280 250 1500 310 280 1500
    comp. ex. 603 300 1500
    sintered body's capsule's inner diameter, and diameter & length after additional HIP (mm)
    final diameter: 300 mm 9th time 10th time
    sample capsule's capsule's
    no. inner diam. diam. length inner diam. diam. length
    ex. 23 501 320 290 1500 317 300 1500
    502 330 300 1500
    503 323 300 1500
    comp. ex. 603
  • TABLE 41
    sintered body's relative density (%)
    final diameter: 300 mm front end 1 center 2 rear end 3
    sample loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. 4 5 6 4 5 6 4 5 6
    ex. 23 501 100 100 100 100 100 100 100 100 100
    502 100 99.9 100 100 99.9 99.9 100 100 99.9
    503 99.7 99.5 99.6 99.8 99.6 99.6 99.8 99.7 99.7
    comp. ex. 603 99.5 99.2 99.1 99.4 99.1 99.0 99.5 99.0 99.1
  • As shown in Table 41, it has been confirmed that the Mo materials of Sample Nos. 501 to 503 of Example 23 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 501 and 502 of Example 23 had a relative density of 99.9% or more. It has been confirmed that the Mo material of Sample No. 603 as a Comparative Example had a relative density including a portion less than 99.5%.
  • From the results of Examples 21 to 23, it has been confirmed that a Mo material that contains 0.3% by mass or more and 1.5% by mass or less of titanium, 0.03% by mass or more and 0.1% by mass or less of zirconium, and 0.01% by mass or more and 0.3% by mass or less of carbon, with a balance composed of molybdenum and unavoidable impurity, can also have a relative density of 99.5% or more, and furthermore, can also have a relative density of 99.9% or more.
    • Example 24
  • In Example 24, Mo materials for Sample Nos. 701 to 705 and 601 were produced in the same manner as in Example 21 except that HIP was not additionally performed. Table 42 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 24. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 43.
  • TABLE 42
    sample ex. 24 comp. ex.
    no. 701 702 703 704 705 601
    weighed Mo 99.66 99.66 99.66 99.66 99.66 99.66
    value Ti 0.3 0.3 0.3 0.3 0.3 0.3
    (mass %) Zr 0.03 0.03 0.03 0.03 0.03 0.03
    C 0.01 0.01 0.01 0.01 0.01 0.01
    measured Mo 99.596 99.603 99.593 99.605 99.602 99.604
    value of Ti 0.310 0.300 0.310 0.300 0.300 0.300
    composition Zr 0.030 0.032 0.031 0.030 0.031 0.031
    (mass %) C 0.010 0.010 0.011 0.010 0.011 0.010
    unavoidable 0.050 0.050 0.050 0.050 0.051 0.005
    impurity
    unavoidable 0.004 0.005 0.005 0.005 0.005 0.005
    gaseous
    impurity
  • TABLE 43
    relative density (%)
    capsule's sintered core front end 1 center 2 rear end 3
    sample inner body size (mm) loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. diam. diam. length 4 5 6 4 5 6 4 5 6
    ex. 24 701 43 20 1500 100 100 100 100 100 100 100 100 100
    702 60 30 1500 100 100 99.9 100 100 100 100 100 99.9
    703 77 40 1500 100 100 99.6 100 100 99.6 100 100 99.6
    comp. ex. 704 93 50 1500 100 100 99.2 100 100 99.1 100 100 99
    705 110 60 1500 100 99.8 98.7 100 99.8 98.7 100 99.8 98.8
    601 510 300 1500 100 98.7 98.0 99.8 98.9 98.1 99.9 99.4 98.2
  • As shown in Table 43, it has been confirmed that the Mo materials of Sample Nos. 701 to 703 of Example 24 had a relative density of 99.6% or more. It has been confirmed that the Mo materials of Sample Nos. 701 and 702 of Example 24 had a relative density of 99.9% or more. It has been confirmed that the Mo materials of Sample Nos. 704, 705 and 601 as Comparative Examples had a relative density including a portion less than 99.5%.
    • Example 25
  • In Example 25, Mo materials for Sample Nos. 801 to 805 and 602 were produced in the same manner as in Example 22 except that HIP was not additionally performed. Table 44 shows a content in mass of each component according to weighed value of raw material powder and content in mass of each component according to a measured value of a composition of each Mo material in Example 25. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 45.
  • TABLE 44
    sample ex. 25 comp. ex.
    no. 801 802 803 804 805 602
    weighed Mo 99.38 99.38 99.38 99.38 99.38 99.38
    value Ti 0.5 0.5 0.5 0.5 0.5 0.5
    (mass %) Zr 0.08 0.08 0.08 0.08 0.08 0.08
    C 0.04 0.04 0.04 0.04 0.04 0.04
    measured Mo 99.325 99.325 99.325 99.325 99.306 99.324
    value of Ti 0.500 0.500 0.500 0.500 0.520 0.500
    composition Zr 0.080 0.081 0.080 0.080 0.080 0.080
    (mass %) C 0.040 0.040 0.039 0.040 0.040 0.041
    unavoidable 0.050 0.049 0.050 0.050 0.050 0.049
    impurity
    unavoidable 0.005 0.005 0.006 0.005 0.004 0.006
    gaseous
    impurity
  • TABLE 45
    relative density (%)
    capsule's sintered core front end 1 center 2 rear end 3
    sample inner body size (mm) loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. diam. diam. length 4 5 6 4 5 6 4 5 6
    ex. 25 801 43 20 1500 100 100 100 100 100 100 100 100 100
    802 60 30 1500 100 100 100 100 100 99.9 100 100 99.9
    803 77 40 1500 100 100 99.6 100 100 99.5 100 100 99.6
    comp. ex. 804 93 50 1500 100 100 99 100 100 99.0 100 100 98.9
    805 110 60 1500 100 99.7 98.6 100 99.6 98.5 100 99.6 98.6
    602 510 300 1500 99.8 99.4 97.9 99.8 99.3 97.9 99.8 99.3 97.8
  • As shown in Table 45, it has been confirmed that the Mo materials of Sample Nos. 801 to 803 of Example 25 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 801 and 802 of Example 25 had a relative density of 99.9% or more. It has been confirmed that the Mo materials of Sample Nos. 804, 805 and 602 of as Comparative Examples had a relative density including a portion less than 99.5%.
    • Example 26
  • In Example 26, Mo materials for Sample Nos. 901 to 905 and 603 were produced in the same manner as in Example 23 except that HIP was not additionally performed. Table 46 shows a content in mass of each component according to a weighed value of raw material powder and a content in mass of each component according to a measured value of a composition of each Mo material in Example 26. In the same manner as in Example 1, test pieces were cut out and subjected to measurement of relative density. A result thereof is shown in Table 47.
  • TABLE 46
    sample ex. 26 comp. ex.
    no. 901 902 903 904 905 603
    weighed Mo 98.10 98.10 98.10 98.10 98.10 98.10
    value Ti 1.5 1.5 1.5 1.5 1.5 1.5
    (mass %) Zr 0.10 0.10 0.10 0.10 0.10 0.10
    C 0.30 0.30 0.30 0.30 0.30 0.30
    measured Mo 98.062 98.045 98.056 98.048 98.057 98.044
    value of Ti 1.490 1.500 1.490 1.500 1.490 1.500
    composition Zr 0.098 0.100 0.099 0.098 0.100 0.100
    (mass %) C 0.295 0.300 0.300 0.298 0.299 0.300
    unavoidable 0.050 0.051 0.050 0.050 0.049 0.051
    impurity
    unavoidable 0.005 0.004 0.005 0.006 0.005 0.005
    gaseous
    impurity
  • TABLE 47
    relative density (%)
    capsule's sintered core front end 1 center 2 rear end 3
    sample inner body size (mm) loc. loc. loc. loc. loc. loc. loc. loc. loc.
    no. diam. diam. length 4 5 6 4 5 6 4 5 6
    ex. 26 901 43 20 1500 100 100 100 100 100 100 100 100 100
    902 60 30 1500 100 100 99.9 100 100 99.9 100 100 99.9
    903 77 40 1500 100 99.9 99.5 100 99.8 99.5 100 99.7 99.6
    comp. ex. 904 93 50 1500 100 99.2 98.9 100 99.3 98.8 100 99.5 98.9
    905 110 60 1500 100 99.1 98.5 100 99 98.5 100 99.2 98.6
    603 510 300 1500 99.5 99.2 97.7 99.4 99.1 97.8 99.5 99 97.7
  • As shown in Table 47, it has been confirmed that the Mo materials of Sample Nos. 901 to 903 of Example 26 had a relative density of 99.5% or more. It has been confirmed that the Mo materials of Sample Nos. 901 and 902 of Example 26 had a relative density of 99.9% or more. It has been confirmed that the Mo materials of Sample Nos. 904, 905, 603 as Comparative Examples had a relative density including a portion less than 99.5%.
  • From the results of Examples 24 to 26, it has been confirmed that a Mo material that contains 0.3% by mass or more and 1.5% by mass or less of titanium, 0.03% by mass or more and 0.1% by mass or less of zirconium, and 0.01% by mass or more and 0.3% by mass or less of carbon, with a balance composed of molybdenum and unavoidable impurity, can also have a relative density of 99.5% or more, and furthermore, can also have a relative density of 99.9% or more.
  • It should be understood that the embodiments and examples disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the appended claims rather than by the embodiments described above, and is intended to include all modifications within the scope and meaning equivalent to the claims.
    • REFERENCE SIGNS LIST
  • 1 front end, 2 center, 3 rear end, 4-6 location, 10 raw material powder, 21 capsule, 22 lid, 23 pipe, 24 seal portion, 25 tip.

Claims (5)

1. A molybdenum material having a diameter of 75 mm or more and a length of 250 mm or more, and having a relative density of 99.5% or more.
2. The molybdenum material according to claim 1, wherein the relative density is 99.9% or more.
3. The molybdenum material according to claim 1, that contains 99.9% by mass or more of molybdenum.
4. The molybdenum material according to claim 1, that contains 0.3% by mass or more and 1.5% by mass or less of titanium, 0.03% by mass or more and 0.1% by mass or less of zirconium, and 0.01% by mass or more and 0.3% by mass or less of carbon, with a balance composed of molybdenum and unavoidable impurity.
5. A method for manufacturing a molybdenum material, comprising:
(1) preparing a first core alloy having an outer diameter of 40 mm or less by hot isostatic pressing;
(2) disposing the first core alloy in a tube having a diameter larger than that of the first core alloy;
(3) disposing molybdenum powder in the tube around the first core alloy and subsequently compressing the tube by hot isostatic pressing; (4) removing the compressed tube to form a second core alloy having a diameter larger than that of the first core alloy; and repeating the steps (2) to (4) to obtain a molybdenum material according to claim 1.
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JP2005307225A (en) * 2004-04-16 2005-11-04 Hitachi Metals Ltd Mo TARGET MATERIAL
KR20160085756A (en) * 2013-10-29 2016-07-18 플란제 에스이 Sputtering target and production method
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