JPWO2020213719A1 - Titanium alloy plate, titanium alloy plate manufacturing method, copper foil manufacturing drum and copper foil manufacturing drum manufacturing method - Google Patents

Abstract

This titanium alloy plate is composed of a group consisting of Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0% or less in mass%. 1 type or 2 types or more: 0.2% or more and 7.0% or less in total, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, O: 0.700 % Or less and Fe: 0.500% or less, the balance has a chemical composition containing Ti and impurities, the average crystal grain size is 40 μm or less, and the log of the crystal grain size (μm) The standard deviation of the particle size distribution based on this is 0.80 or less, the crystal structure includes an α phase having a hexagonal close-packed structure, and the angle formed by the α phase in the [0001] direction with respect to the plate thickness direction is 0 ° or more and 40. The area ratio of crystal grains below ° is 70% or more.

Description

The present invention relates to a titanium alloy plate, a method for manufacturing a titanium alloy plate, a copper foil manufacturing drum, and a method for manufacturing a copper foil manufacturing drum.
This application claims priority based on Japanese Patent Application No. 2019-078824 filed in Japan on April 17, 2019, and Japanese Patent Application No. 2019-078288 filed in Japan on April 17, 2019. And the contents are used here.

Copper foil is often used as a raw material for wiring of wiring boards such as multilayer wiring boards and flexible wiring boards, and for conductive parts of electronic components such as current collectors of lithium ion batteries.

The copper foil used for such applications is manufactured by a copper foil manufacturing apparatus including a copper foil manufacturing drum. FIG. 7 is a schematic view of a copper foil manufacturing apparatus. As shown in FIG. 7, for example, the copper foil manufacturing apparatus 1 includes an electrolytic cell 10 in which a copper sulfate solution is stored, and an electric electrode provided in the electrolytic cell 10 so that a part of the copper sulfate solution is immersed in the copper sulfate solution. It includes a landing drum 2 and an electrode plate 30 which is immersed in a copper sulfate solution in an electrolytic cell 10 and is provided so as to face the outer peripheral surface of the electrodeposition drum 2 at predetermined intervals. By applying a voltage between the electrodeposition drum 2 and the electrode plate 30, the copper foil A is electrodeposited on the outer peripheral surface of the electrodeposition drum 2 to be generated. The copper foil A having a predetermined thickness is peeled off from the electrodeposition drum 2 by the take-up portion 40, and is taken up by the take-up roll 60 while being guided by the guide roll 50.

As a material for a drum (electroplated drum), titanium is generally used for the surface (outer peripheral surface) of the drum (depositioned drum) from the viewpoints of excellent corrosion resistance and excellent peelability of copper foil. However, even when a titanium material having excellent corrosion resistance is used, if the copper foil is manufactured for a long period of time, the surface of the titanium material constituting the drum is gradually corroded in the copper sulfate solution. Then, the state of the corroded drum surface can be transferred to the copper foil during the production of the copper foil.

It is known that the corrosion state and degree of corrosion of a metal material differ depending on various internal factors caused by the metal structure such as crystal structure, crystal orientation, defects, segregation, processing strain, and residual strain of the metal material. Has been done. When a drum using a metal material having an inhomogeneous metal structure between parts is corroded due to the production of copper foil, the homogeneous surface state of the drum cannot be maintained, and an inhomogeneous surface is generated on the drum surface. The heterogeneous surface generated on the drum surface can be identified as a pattern. Among the patterns caused by such an inhomogeneous metal structure, a pattern caused by a macrostructure having a relatively large area and which can be discriminated with the naked eye is called a "macro pattern". The macro pattern generated on the drum surface can be transferred to the copper foil during the production of the copper foil.

Therefore, in order to produce a copper foil with high accuracy and uniform thickness, the macrostructure of the titanium material constituting the drum is homogenized, and the corrosion on the surface of the drum is homogenized, so that the macrostructure is inhomogeneous. It is important to reduce the macro pattern caused by.

Patent Document 1 contains Cu: 0.15% or more and less than 0.5%, oxygen: more than 0.05%, 0.20% or less, Fe: 0.04% or less in mass%, and the balance of titanium. A titanium plate for an electrolytic Cu foil manufacturing drum has been proposed, which comprises unavoidable impurities and has an α-phase homogeneous fine recrystallization structure having an average crystal grain size of less than 35 μm.

Patent Document 2 contains Cu: 0.3 to 1.1%, Fe: 0.04% or less, oxygen: 0.1% or less, hydrogen: 0.006% or less in mass%, and average crystal grains. At a portion having a diameter of 8.2 or more and a Vickers hardness of 115 or more and 145 or less and parallel to the plate surface, the texture is α-phase (0001) from the normal direction (ND axis) from the rolled surface. ) In the plane pole diagram, the tilt angle of the normal of the (0001) plane is within the range of an ellipse with ± 45 ° in the rolling width direction TD direction as the major axis and ± 25 ° in the final rolling direction RD direction as the minor axis. A titanium plate for an electrolytic Cu foil manufacturing drum is proposed, wherein the total area of the crystal grains existing in the above is A, the total area of the other crystal grains is B, and the area ratio A / B is 3.0 or more. Has been done.

Patent Document 3 contains Al: 0.4 to 1.8%, and has an average crystal grain size of 4 mm or more, 1.0 mm below the surface, and a portion parallel to the plate surface of 1/2 plate thickness. 2 or more, Vickers hardness 115 or more and 145 or less, the texture is the TD (0001) plane in the normal ND rolling width direction of the final rolling direction RD rolling surface at the portion parallel to the plate surface extending from 1 mm below the surface to 1/2 plate thickness. When the normal line of is the c-axis, the tilt angle of the c-axis in the TD direction in the (0001) plane pole diagram of the α phase from the normal direction from the rolled surface is 45 to 45 °, and the c-axis RD direction. The total area of the crystal grains having the c-axis in the elliptical region where the tilt angle to 25 to 25 ° is A, the total area of the other crystal grains is B, and the area ratio A / B is 3. Titanium alloy thick plates of 0 or more have been proposed.

Patent Document 4 describes that when titanium and a titanium alloy plate are manufactured by a method including a step of sequentially performing lump forging, coarse hot rolling and finishing hot rolling, the heating temperature in the lump forging and rough hot rolling is 950 ° C. or higher. It has a uniform and fine macro pattern, characterized in that the heating temperature in the finish hot rolling is 700 ° C. or less, and the cross hot rolling in which the rolling directions of the rough hot rolling and the finishing hot rolling are changed is carried out. A method for producing titanium and a titanium alloy plate has been proposed.

Patent Document 5 describes a titanium cathode electrode made of a titanium material used when obtaining an electrolytic copper foil using a copper electrolytic solution, wherein the titanium material has a crystal grain size number of 7.0 or more and contains initial hydrogen. A titanium cathode electrode for producing an electrolytic copper foil, characterized in that the amount is 35 ppm or less, has been proposed. In Patent Document 5, if this titanium cathode electrode is used, it can be used for an extremely long period of time in the production of electrolytic copper foil, the number of maintenances can be effectively reduced, and a high quality electrolytic copper foil can be produced for a long period of time. It is disclosed that it will be possible to manufacture across.

Patent Document 6 contains Cu: 0.5 to 2.1%, Ru: 0.05 to 1.00%, Fe: 0.04% or less, and oxygen: 0.10% or less in mass%. A titanium plate for an electrolytic Cu foil manufacturing drum, which is composed of a residual titanium and unavoidable impurities and has a homogeneous fine recrystallized structure, has been proposed.

However, with the recent miniaturization and high density of electronic components, copper foil is required to be further thinned and improved in surface quality. Under such circumstances, further reduction is required for the above-mentioned macro pattern. The macro pattern could not be sufficiently reduced by the conventional technique as described in Patent Documents 1 to 6.

Further, the drum used for manufacturing copper foil is manufactured by shrink-fitting an insoluble metal plate such as a titanium plate on the surface of the core material which is the core of the copper foil manufacturing drum. From the viewpoint of property, the plate to be shrink-fitted on the surface of the core material is preferably a plate having excellent shrink-fitting property.
However, in the techniques of Patent Documents 1 to 6, it takes time and effort to shrink-fit the core material and the titanium plate, and there is room for improvement in the productivity of the copper foil manufacturing drum.

In addition to being manufactured by ring forging, the copper foil manufacturing drum described above is manufactured by bending a titanium plate into a cylindrical shape and welding adjacent ends. The latter method is suitable for producing a high-quality copper foil production drum because it is easy to control the metal structure of the titanium plate. By homogenizing the macrostructure of the titanium material constituting the copper foil manufacturing drum and achieving homogeneous corrosion of the drum, it is possible to reduce the macro pattern caused by the inhomogeneous macrostructure. However, since the metal structure of the welded part of the drum manufactured by welding is inevitably different from that of other parts, even if the macrostructure of the titanium material used as the surface material of the copper foil manufacturing drum is made uniform. , There is a problem that a macro pattern caused by a welded portion is likely to occur.
Although the proportion of welded parts on the surface of the copper foil manufacturing drum is not large, in recent years there has been an increasing demand for reducing the macro pattern of the welded parts.

Regarding welding of titanium material, Patent Document 7 describes for forming a molten metal, which has a predetermined tensile strength in the longitudinal direction of the wire rod and has a Ti-based oxide film having a thickness of 1 μm or more and 5 μm or less formed on the surface of the wire rod main body. Ti-based wire rods have been proposed. Further, Patent Document 8 describes a welding wire made of Ti or a Ti alloy, which has an oxygen-enriched layer on its surface and further has a metal compound having at least one metal selected from the group of alkali metals and alkaline earth metals. Has been proposed.

However, the techniques described in Patent Documents 7 and 8 are not intended to improve welding and the structure of welded portions in the production of copper foil manufacturing titanium drums. Therefore, it is difficult to suppress the macro pattern using the same technique. That is, a titanium rod wire for welding, which is used in the production of a titanium drum produced by copper foil and can suppress the occurrence of macro patterns in the welded portion of the titanium drum produced by copper foil, has not been sufficiently studied.

Japanese Patent Application Laid-Open No. 2009-41064 Japanese Patent Application Laid-Open No. 2012-112017 Japanese Patent Application Laid-Open No. 2013-7063 Japanese Patent Application Laid-Open No. 60-9866 Japanese Patent Application Laid-Open No. 2002-194585 Japanese Patent Application Laid-Open No. 2005-298853 Japanese Patent Application Laid-Open No. 2005-21983 Japanese Patent Application Laid-Open No. 2006-291267

The present invention has been made in view of the above problems, and an object of the present invention is to use a titanium alloy plate and a titanium alloy plate capable of suppressing the generation of macro patterns when used in a drum for producing copper foil. To provide a copper foil manufacturing drum manufactured by.
Further, a preferred object of the present invention is to use a titanium alloy plate and a titanium alloy plate which can suppress the generation of macro patterns when used in a drum for producing copper foil and have excellent shrink fit. To provide copper foil manufacturing drums.

Another preferred object of the present invention is the production of copper foil using a titanium wire rod for welding, which is used in the production of a copper foil production titanium drum and can suppress the generation of macro patterns in the welded portion of the copper foil production titanium drum. It is an object of the present invention to provide a method for manufacturing a drum and a copper foil manufacturing drum.

The present inventors have diligently studied to solve the above-mentioned problems. As a result, simply reducing the crystal grain size of the texture in the titanium material or making the normal of the (0001) plane of the crystal close to perpendicular to the rolled plane (plate surface) is macro to the level required this time. It was found that the occurrence of patterns could not be suppressed.

As a result of further studies by the present inventors, the chemical composition is a chemical composition in which the precipitation of the β phase is suppressed, and the crystal grains are not only fine but also have a uniform size in the structure, and the structure has a hexagonal close-packed crystal structure. The area ratio of crystal grains containing the α phase, which is a close-packed structure, and the angle formed by the α phase in the [0001] direction (c axis) with respect to the plate thickness direction is 0 ° or more and 40 ° or less is set to 70% or more, preferably further. In the (0001) pole diagram from the normal direction of the plate surface, the peak of the degree of accumulation of crystal grains exists within 30 ° from the normal direction of the plate surface, and the maximum degree of integration is 4.0 or more. It was found that the occurrence of macro patterns can be suppressed by controlling the structure so that it becomes an aggregate structure. Then, they have found a method for producing a titanium alloy plate capable of simultaneously achieving such a chemical composition and texture, and have reached the present invention.

In addition, the present inventors have also studied the shrinkage fit of a titanium alloy plate into a core material in the production of a copper foil production drum. As a result, it was found that the Young's modulus of the titanium alloy plate affects the shrink fit.
Based on this finding, the present inventors focused on the hardness, grain size, crystal orientation, second phase, and element distribution of the titanium alloy plate. As a result, when Al is contained in a larger amount than the titanium alloy plate used for a drum for general copper foil production, grain growth is suppressed and a fine structure is easily formed, and the hardness of the titanium alloy plate is increased. At the same time, it was found that the Young's modulus of the titanium alloy plate is improved.

In addition, the present inventors have studied the suppression of the occurrence of macro patterns in welded parts. As a result, it was found that it is possible to suppress the occurrence of macro patterns in the welded portion by using the metal structure of the welded portion as the main component of the α phase, making the crystal grains finer and controlling the hardness. Further, in order to obtain the structure of such a welded portion, it is effective to include an appropriate amount of one or more selected from the group consisting of Sn, Zr and Al and O in the titanium wire for welding. I found that there is.

The gist of the present invention completed based on the above findings is as follows.
[1] The titanium alloy plate according to one aspect of the present invention has Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0 in mass%. 1 type or 2 types or more composed of a group consisting of% or less: 0.2% or more and 7.0% or less in total, N: 0.100% or less, C: 0.080% or less, H: 0. It has a chemical composition containing 015% or less, O: 0.700% or less, and Fe: 0.500% or less, the balance containing Ti and impurities, and has an average crystal grain size of 40 μm or less. The standard deviation of the particle size distribution based on the logarithm of the crystal particle size in the unit μm is 0.80 or less, the crystal structure includes an α phase having a hexagonal close-packed structure, and the α phase [0001] with respect to the plate thickness direction. ] The area ratio of the crystal grains having an angle of 0 ° or more and 40 ° or less in the direction is 70% or more.
[2] The titanium alloy plate according to the above [1] has a development index of the pole diagram using the spherical harmonic method of the electron backscatter diffraction method in the (0001) pole diagram from the normal direction of the plate surface. 16. The peak of the degree of integration calculated by the Function analysis when the Gaussian full width at half maximum is 5 ° exists within 30 ° from the normal direction of the plate surface, and the maximum degree of integration is 4.0 or more. It may have an aggregate structure that is.
[3] In the titanium alloy plate according to the above [1] or [2], when the average crystal grain size is D in the unit μm, the standard deviation of the particle size distribution is (0.35 × lnD−). It may be 0.42) or less.
[4] The titanium alloy plate according to any one of [1] to [3] above has a total grain boundary of the plate thickness cross section at a position of 1/4 of the plate thickness from the surface when the plate thickness direction cross section is observed. The ratio of the twin grain boundary length to the length may be 5.0% or less.
[5] The titanium alloy plate according to any one of [1] to [4] above has Sn: 0.2% or more and 2.0% or less and Zr: 0.2% or more and 5.0 in the chemical composition. 1 type or 2 types or more composed of a group consisting of% or less and Al: 0.2% or more and 3.0% or less may be contained in a total of 0.2% or more and 5.0% or less.
[6] The titanium alloy plate according to any one of [1] to [4] above contains Al: more than 1.8% and 7.0% or less in the chemical composition, and has a Vickers hardness of 350 Hv or less. There may be.
[7] The titanium alloy plate according to the above [6] has an Al content of [Al%], a Zr content of [Zr%], a Sn content of [Sn%], and an O content in mass%. When is [O%], the Al equivalent Aleq represented by the following formula (1) may be 7.0 or less.
Alex = [Al%] + [Zr%] / 6 + [Sn%] / 3 + 10 × [O%] Equation (1)
[8] The titanium alloy plate according to the above [6] or [7] is analyzed using an electron probe microanalyzer on a surface 20 mm × 20 mm or more perpendicular to the plate thickness direction at a position 1/4 of the plate thickness from the surface. When the region was analyzed for composition, the average content of Al was [Al%], and the concentration of Al was ([Al%] -0.2) mass% or more ([Al%] +0) with respect to the area of the analysis region. .2) The area ratio of the region of mass% or less may be 90% or more.
[9] The titanium alloy plate according to any one of the above [1] to [8] may contain the α phase in an amount of 98.0% by volume or more.
[10] The titanium alloy plate according to any one of [1] to [9] above may be a titanium alloy plate for a copper foil manufacturing drum.
[11] The copper foil manufacturing drum according to another aspect of the present invention includes a cylindrical inner drum and titanium according to any one of [1] to [10], which is adhered to the outer peripheral surface of the inner drum. It has an alloy plate and a welded portion provided at a butt portion of the titanium alloy plate, and the metal structure of the welded portion has an α phase of 98.0% or more in terms of volume ratio, and JIS G 0551 : A particle size number based on 2013, which is 6 or more and 11 or less.
[12] A method for manufacturing a copper foil manufacturing drum according to another aspect of the present invention includes a welding step of welding two adjacent ends of a titanium alloy plate processed into a cylindrical shape using a titanium wire for welding. The titanium wire for welding is one or more selected from the group consisting of Sn, Zr and Al in mass%: 0.2% or more and 6.0% or less in total, O: 0.01% or more and 0. Chemical composition containing .70% or less, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, and Fe: 0.500% or less, and the balance containing Ti and impurities. Has.
[13] The method for manufacturing a copper foil manufacturing drum according to the above [12] is one type in which at least a part of the O is selected from the group consisting of Ti, Sn, Zr and Al in the titanium wire rod for welding. It may exist as an oxide of the above elements.

According to the above aspect of the present invention, there is provided a titanium alloy plate capable of suppressing the generation of macro patterns when used in a drum for producing copper foil, and a copper foil production drum produced by using the titanium alloy plate. It becomes possible.
Further, according to a preferred embodiment of the present invention, it is possible to provide a titanium alloy plate capable of suppressing the generation of macro patterns when used in a drum for producing copper foil and having excellent shrink fit.
Further, according to a preferred embodiment of the present invention, it is possible to provide a method for manufacturing a copper foil manufacturing drum and a copper foil manufacturing drum that suppresses the generation of macro patterns in a welded portion of the copper foil manufacturing drum.

It is an example of the (0001) pole figure from the normal direction (ND) from the rolled surface of the titanium alloy plate which concerns on one Embodiment of this invention. It is a micrograph which shows an example of the macro pattern observed on the surface of a titanium alloy plate after corrosion. It is a reference figure which emphasized a macro pattern to show the position of a macro pattern. It is explanatory drawing for demonstrating the crystal orientation of α phase. This is an example of a crystal orientation map showing an example of crystal orientation analysis. It is explanatory drawing of (0001) pole point drawing from the normal direction (ND) of the rolled surface for demonstrating the crystal orientation of the titanium alloy plate which concerns on one Embodiment of this invention. It is a schematic diagram of a copper foil manufacturing apparatus. It is a schematic diagram of the copper foil manufacturing drum which concerns on this embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail.
<1. Titanium alloy plate ＞
First, the titanium alloy plate according to the present embodiment will be described. The titanium alloy plate according to the present embodiment is assumed to be used as a material for a drum for producing copper foil (copper foil manufacturing drum). Therefore, it can be said that the titanium alloy plate according to the present embodiment is a titanium alloy plate for a copper foil manufacturing drum. When used in a copper foil manufacturing drum, one side of the titanium alloy plate constitutes the cylindrical surface of the drum.

(1.1 Chemical composition)
First, the chemical composition of the titanium alloy plate according to the present embodiment will be described. The titanium alloy plate according to the present embodiment is composed of Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0% or less in mass%. 1 type or 2 or more types composed of groups, 0.2% or more and 7.0% or less in total, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, It contains O: 0.700% or less and Fe: 0.500% or less, and the balance contains Ti and impurities. In the following, unless otherwise specified, the notation of "%" regarding the chemical composition shall represent "mass%".

Industrial pure titanium has an extremely small amount of additive elements and has a substantially α-phase single-phase structure. If such a titanium alloy plate manufactured of pure titanium for industrial use is used for the drum, the drum is uniformly corroded when the drum is immersed in the copper sulfate solution. As a result, the generation of macro patterns due to the difference in the corrosion rate between the α phase and the β phase is suppressed.

The titanium alloy plate according to the present embodiment is substantially α-phase single-phase industrial pure titanium, in terms of mass%, Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, And Al: 1 type or 2 types or more composed of a group consisting of 0% or more and 7.0% or less, so as to be 0.2% or more and 7.0% or less in total. ..
The reason for limiting the content of each element will be described.

<Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0% or less. 0.2% or more and 7.0% or less>
When the total content of one or more selected from the group consisting of Sn, Zr and Al is 0.2% or more, the grain growth can be stably suppressed.
On the other hand, by setting the total content of one or more selected from the group consisting of Sn, Zr and Al to 7.0% or less, the above-mentioned deformation of the titanium alloy plate after hot rolling is caused. The high temperature strength is such that it does not occur. From the viewpoint of high temperature strength, the Al content is preferably 0.2% or more and 3.0% or less, and the total content of one or more selected from the group consisting of Sn, Zr and Al. Is 0.5% or more and 5.0% or less. The total content of one or more selected from the group consisting of Sn, Zr and Al is more preferably 0.5% or more and 4.0% or less.

Sn is a neutral element and is an element that suppresses crystal grain growth by being dissolved in titanium. When the Sn content is 0.2% or more, the crystal grain growth can be stably suppressed. Therefore, the Sn content is preferably 0.2% or more. The Sn content is more preferably 0.3% or more.
In addition, Sn is dissolved in the α phase and β phase in titanium to stabilize each phase. If the Sn content is too high, the high-temperature strength becomes high, and the reaction force during hot rolling distorts the plate shape after hot rolling and tends to form a wavy shape. Dislocations are introduced into the crystals of the titanium alloy plate by applying strain to the wavy titanium alloy plate by processing to correct the shape. Due to this dislocation, macro patterns are likely to occur. On the other hand, if the Sn content is too large, the toughness of the titanium alloy plate becomes small, the shrink-fitting property at the time of manufacturing the copper foil manufacturing drum is lowered, and the productivity is lowered. Therefore, the Sn content is preferably 2.0% or less, more preferably 1.5% or less. Since Sn is not essential in the titanium alloy plate, the Sn content may be 0% when Zr and / or Al is contained in an amount of 0.2% or more in total.

Zr is a neutral element like Sn, and is an element that suppresses crystal grain growth by being dissolved in titanium. When the Zr content is 0.2% or more, crystal grain growth can be stably suppressed. Therefore, the Zr content is preferably 0.2% or more. The Zr content is more preferably 0.3% or more.
On the other hand, Zr is an element that stabilizes each phase by being dissolved in the α phase and β phase in titanium. If the Zr content is too high, the temperature range in which the two phases of α phase and β phase are thermally stable becomes wide, and the β phase tends to precipitate during heating. Since the β phase corrodes preferentially over the α phase, when a drum having a titanium alloy plate containing the β phase on the surface is used for producing copper foil, the β phase is preferentially corroded and macroscopically appears on the drum surface. A pattern occurs. As a result, the macro pattern may be transferred to the copper foil. Further, due to solidification segregation, a difference in strength is generated between the portions of the titanium alloy plate, and a macro pattern is generated when the obtained titanium alloy plate is polished. Therefore, the Zr content is 5.0% or less. The Zr content is preferably 4.5% or less, more preferably 4.0%. The Zr content is more preferably 2.5% or less, still more preferably 2.0% or less. Since Zr is not essential in the titanium alloy plate, the Zr content may be 0% when Sn and / or Al is contained in an amount of 0.2% or more in total.

Al is an α-phase stabilizing element and suppresses grain growth in heat treatment in an α-phase single-phase temperature range, similarly to Sn and Zr. When the Al content is 0.2% or more, the crystal grain growth can be stably suppressed. Therefore, the Al content is preferably 0.2% or more. The Al content is more preferably 0.5% or more.
Al is also an element that increases Young's modulus of the titanium alloy plate. By increasing the Young's modulus, the shrink-fitting property when the core material and the titanium alloy plate are shrink-fitted in the production of the copper foil manufacturing drum is improved. This improves the productivity of the copper foil manufacturing drum. Further, by increasing the Young's modulus, the titanium alloy plate is uniformly shrink-fitted and the polishability of the titanium alloy plate is improved. As a result, it is possible to further suppress the occurrence of macro patterns.
From the viewpoint of increasing the Young's modulus and improving the shrink fit, the Al content is preferably more than 1.8%.
On the other hand, Al further increases the high temperature strength of the titanium alloy plate as compared with Sn or Zr. As will be described later, when the titanium alloy plate according to the present embodiment is manufactured, hot rolling is carried out to a relatively low temperature for the purpose of controlling the texture. Therefore, if the high-temperature strength becomes too high, the reaction force during hot rolling becomes large, the shape of the titanium alloy plate after hot rolling is greatly distorted, and the titanium alloy plate becomes wavy. Therefore, a lot of subsequent corrections are required for the titanium alloy plate, but if strain is applied at that time, many dislocations are introduced. As a result, when the titanium alloy plate is used for the drum, a macro pattern is likely to occur. If the Al content is more than 7.0%, the toughness and workability are lowered, and drum production becomes difficult. As a result, the productivity of the copper foil manufacturing drum is reduced. Therefore, the Al content is set to 7.0% or less. From the above viewpoint, the Al content is preferably 3.0% or less, and more preferably 2.5% or less. Since Al is not essential in the titanium alloy plate, the Al content may be 0% when Sn and / or Zr are contained in a total of 0.2% or more.

Further, if the Al content is high, there is a concern that segregation may occur in Al. When segregation occurs in Al, there is a difference in hardness and electrical resistance between the portions of the titanium alloy plate. In the titanium alloy plate having variations in hardness, large irregularities may be formed on the titanium alloy plate during polishing, and a macro pattern may occur. In addition, variations in electrical resistance may cause differences in the corrosion rate, resulting in macro patterns. Therefore, the concentration distribution of Al should be small.
In the titanium alloy plate according to the present embodiment, when the Al content is more than 1.8% and the Al content (average content) is [Al%], the Al concentration is ([Al%]. ] -0.2) Mass% or more ([Al%] +0.2) mass% or less The area ratio of the region is preferably 90% or more. As a result, the macro pattern can be stably suppressed.

The segregation of Al is evaluated by an electron probe microanalyzer (EPMA) with a beam diameter of 500 μm and a step size of 500 μm, which is the same as the beam diameter. It is performed by analyzing the composition of a region of 20 mm × 20 mm or more at the position of 4. In order to convert the composition analysis result into the alloy element concentration, the average chemical composition and Kα ray intensity of JIS Class 1 industrial pure titanium and the target titanium alloy plate are analyzed, and linear approximation is obtained from the results. A calibration curve is used.

Further, in the titanium alloy plate according to the present embodiment, the Al content is [Al%] (mass%), the Zr content is [Zr%] (mass%), and the Sn content is [Sn%] (mass%). When the O content is [O%] (mass%), the Al equivalent alloy represented by the following formula (1) is preferably 7.0 (mass%) or less.
Alex = [Al%] + [Zr%] / 6 + [Sn%] / 3 + 10 × [O%] Equation (1)
The Al equivalent is an index indicating the degree of stabilization of the α phase, and as the Al equivalent increases, the hardness increases while the toughness decreases. By setting the Al equivalent to 7.0% by mass or less, the toughness can be maintained and the shrink fit can be improved.

<O: 0.700% or less>
O is an element that contributes to the improvement of the strength of the titanium alloy plate and the increase of the surface hardness. However, if the strength of the titanium alloy plate becomes too high, relatively large processing is required at the time of forcing, and twinning is likely to occur. Further, if the surface hardness becomes too large, it becomes difficult to polish the titanium alloy plate as a drum. Therefore, when O is contained in the titanium alloy plate, the O content is set to 0.700% or less. The O content is preferably 0.400% or less. The O content is more preferably 0.150% or less, still more preferably 0.120% or less. Since O is not essential in the titanium alloy plate, the lower limit of its content is 0%. However, it is difficult to prevent contamination from titanium sponge, which is a dissolving raw material, and additive elements, and the practical lower limit is 0.020%.
When the strength improving effect is obtained by the O content, the O content is preferably 0.030% or more.

<Fe: 0.500% or less>
Fe is an element that reinforces the β phase. In the titanium alloy plate, if the amount of β-phase precipitation increases, it affects the formation of macro patterns. Therefore, when Fe is contained in the titanium alloy plate, the upper limit of the Fe content is set to 0.500%. The Fe content is preferably 0.100% or less, more preferably 0.080% or less. Since Fe is not essential in the titanium alloy plate, the lower limit of its content is 0%. However, it is difficult to prevent Fe from being mixed in the actual production, and the practical lower limit is 0.001%.

<N: 0.100% or less>
<C: 0.080% or less>
<H: 0.015% or less>
The titanium alloy plate according to the present embodiment may further contain N, C, or H as impurities.
N is an element that forms a nitride together with Ti. When the nitride is formed, the titanium alloy plate may be hardened or embrittled. Therefore, it is preferable to suppress the content of N as much as possible. The titanium alloy plate according to this embodiment has an N content of 0.100% or less. The N content is preferably 0.080% or less. Since N is not essential in the titanium alloy plate, the lower limit of its content is 0%. However, N is an impurity mixed in during the manufacturing process, and the lower limit of the substantial N content may be 0.0001%.

C is an element that forms carbides together with Ti and hardens or embrittles the titanium alloy plate in the same manner as nitrides. The C content is preferably as low as possible in order to suppress hardening and embrittlement of the titanium alloy plate. The titanium alloy plate according to this embodiment has a C content of 0.080% or less. The C content is preferably 0.050% or less. Since C is not essential in the titanium alloy plate, the lower limit of its content is 0%. However, C is an impurity mixed in during the manufacturing process, and the lower limit of the substantial C content may be 0.0005%.

H is an element that forms a hydride with Ti. When hydrides are formed, the titanium alloy plate may become embrittled. In addition, macro patterns may occur due to hydrides. Therefore, it is preferable to suppress the H content as much as possible. The titanium alloy plate according to this embodiment has an H content of 0.015% or less. The H content is preferably 0.010% or less. Since H is not essential in the titanium alloy plate, the lower limit of its content is 0%. However, H is an impurity mixed in during the manufacturing process, and the lower limit of the substantial H content may be 0.0005%.

The balance of the chemical composition of the titanium alloy plate according to the present embodiment contains Ti and impurities, and may consist of Ti and impurities. Impurities are Cl, Na, Mg, Si, Ca mixed in the refining process and Mo, Nb, Ta, V, Cr, Mn, Co, Ni mixed in from scrap, to give a specific example other than the above-mentioned elements. , Cu and the like. There is no problem if the total content of impurities is 0.50% or less.
However, the above impurities may include β-phase stabilizing elements. Since a large amount of β-phase precipitation affects the generation of macro patterns, it is preferable that the amount of β-phase stabilizing elements is small. Examples of the β-phase stabilizing element include V, Mo, Ta, Nb, Cr, Mn, Co, Ni, Cu and the like. In the titanium alloy plate according to the present embodiment, the total content of impurities is 0.50% or less, and the content of each β-phase stabilizing element contained in the titanium alloy plate is 0.10% or less. Is more preferable.

The chemical composition is determined by the following method.
Β-stabilizing elements such as Al, Zr, Sn, Fe, V, Mo, Ta, Nb, Cr, Mn, Co, Ni and Cu can be measured by IPC emission spectrum analysis. O and N can be measured by the inert gas melting, thermal conductivity / infrared absorption method using an oxygen / nitrogen simultaneous analyzer. C can be measured by an infrared absorption method using a carbon-sulfur simultaneous analyzer. H can be measured by the melting of an inert gas and the infrared absorption method.

(1.2 Metallographic structure)
Next, the metal structure of the titanium alloy plate according to the present embodiment will be described.
The titanium alloy plate according to the present embodiment has an average crystal grain size of 40 μm or less, a standard deviation of the grain size distribution based on the logarithm of the crystal grain size (μm) of 0.80 or less, and a hexagonal close-packed crystal structure. The area ratio of crystal grains including the α phase, which is a packed structure, and the angle formed by the α phase in the [0001] direction with respect to the plate thickness direction is 0 ° or more and 40 ° or less is 70% or more.
Hereinafter, the metallographic structure of the titanium alloy plate according to the present embodiment will be described in detail step by step.

(1.2.1 Phase composition of metallographic structure)
The metallographic structure of the titanium alloy plate according to the present embodiment includes an α phase having a hexagonal close-packed structure. The metallographic structure of the titanium alloy plate according to the present embodiment may contain a β phase in addition to the α phase. However, the β phase corrodes in preference to the α phase. Therefore, when a titanium drum having a titanium alloy plate containing a β phase on the surface is used for producing a copper foil, the β phase is preferentially corroded to generate a macro pattern on the drum surface, and the macro pattern appears on the copper foil. May be transcribed. Further, when the β phase is aggregated and formed, the texture of the titanium alloy plate may change. Therefore, it is better to have less β phase.
The volume fraction of the α phase in the titanium alloy plate according to the present embodiment is preferably 98.0% or more, more preferably 99.0% or more, and further preferably 100% (α phase single phase). ).

Further, it is preferable that the metal structure of the titanium alloy plate does not include an unrecrystallized portion. Such unrecrystallized portions are generally coarse and can cause macro patterns. Therefore, the metal structure of the titanium alloy plate is preferably a completely recrystallized structure. The recrystallized structure is a structure composed of crystal grains having an aspect ratio of less than 2.0. The presence or absence of unrecrystallized grains can be confirmed by the following method. That is, the crystal grains having an aspect ratio of 2.0 or more are regarded as unrecrystallized grains, and the presence or absence thereof is confirmed. Specifically, a cross section obtained by cutting a titanium alloy plate is chemically polished, and an electron backscatter diffraction method; EBSD (Electron Backscattering Diffraction Pattern) is used to cover a region of 1 to 2 mm × 1 to 2 mm in a region of 1 to 2 μm. In the step of, measure about 2 to 10 fields. After that, the orientation difference boundary of 5 ° or more measured by EBSD is defined as the crystal grain boundary, the range surrounded by the crystal grain boundary is defined as the crystal grain, the major axis and the minor axis of the crystal grain are obtained, and the major axis is the minor axis. The value divided by (major axis / minor axis) is calculated as the aspect ratio. The long axis is the line segment connecting any two points on the grain boundary of the α phase that has the maximum length, and the short axis is orthogonal to the long axis and on the grain boundary. The line segment connecting any two points with the maximum length.
The α-phase single-phase metallographic structure as described above can be achieved by the chemical composition of the titanium alloy plate as described above.

The volume ratio of each phase constituting the metal structure of the titanium alloy plate can be easily measured and calculated by the EPMA (Electron Probe Micronalizer) (SEM / EPMA) attached to the SEM (Scanning Electron Microscopy). Specifically, the arbitrary cross section of the plate is polished to a mirror surface, and at a magnification of 100 times, a 1 mm × 1 mm region at a position 1/4 of the plate thickness from the surface is formed in steps of 1 to 2 μm. The concentration distribution of Fe or other β-phase stabilizing elements is measured using SEM / EPMA in about 5 fields of view. A point (concentrated portion) in which the concentration of Fe or the total concentration of β-phase stabilizing elements is 1 mass% or more higher than the average concentration in the measurement range is defined as β-phase, and the area ratio is obtained. Assuming that the area fraction and the volume fraction are equal, the obtained area fraction is defined as the β-phase volume fraction, and the area fraction of the portion where the β-phase stabilizing element is not concentrated (other than the concentrated portion) is defined as the α-phase volume fraction. ..

(1.2.2 Average grain size and grain size distribution of crystal grains)
Next, the average particle size and the particle size distribution of the crystal grains contained in the metal structure of the titanium alloy plate according to the present embodiment will be described.
First, if the grain size (crystal grain size) of the crystal grains of the metal structure of the titanium alloy plate is coarse, the crystal grains themselves become a pattern and the pattern is transferred to the copper foil, so that the crystal grain size is finer. Is good. When the average crystal grain size of the crystal grains of the metal structure of the titanium alloy plate exceeds 40 μm, the crystal grains themselves become a pattern and the pattern is transferred to the copper foil. Therefore, the average crystal grain size of the crystal grains of the metal structure of the titanium alloy plate is set to 40 μm or less. As a result, the crystal grains become sufficiently fine and the generation of macro patterns is suppressed. The average crystal grain size of the crystal grains of the metal structure of the titanium alloy plate is preferably 38 μm or less, more preferably 35 μm or less.
On the other hand, the lower limit of the average crystal grain size of the crystal grains of the metal structure of the titanium alloy plate is not particularly limited. However, if the crystal grains are very small, unrecrystallized portions may be generated during the heat treatment. Therefore, the average crystal grain size of the crystal grains is preferably 3 μm or more, more preferably 5 μm or more, and further preferably 10 μm or more.

When the β phase is present in the metal structure, the average crystal grain size of the β phase is preferably 0.5 μm or less. When the particle size of the β phase is large, large irregularities may be formed on the titanium alloy plate due to corrosion or polishing. By setting the average crystal grain size of the β phase to 0.5 μm or less, it is possible to suppress the formation of irregularities due to corrosion and polishing.

Further, the present inventors have found that the macro pattern cannot be sufficiently suppressed only by the crystal grains of the metal structure of the titanium alloy plate being simply fine. That is, even if the crystal grains of the metal structure of the titanium alloy plate are fine, if the particle size distribution is wide, coarse crystal grains are present. If there is a portion where such coarse crystal grains and fine crystal grains coexist, a macro pattern may occur due to the difference in particle size. Therefore, it is important that the crystal grains of the metal structure of the titanium alloy plate are not only fine but also have a narrow grain size distribution, that is, a uniform grain size of the crystal grains is important for suppressing the occurrence of macro patterns. The present inventors have found.

Specifically, in the titanium alloy plate according to the present embodiment, the standard deviation of the particle size distribution based on the logarithm of each crystal particle size (μm) is 0.80 or less. When the crystal grains satisfy the standard deviation of such a particle size distribution together with the average particle size as described above, the crystal grains in the metal structure become sufficiently fine and uniform. As a result, when the titanium alloy plate is used for the drum, the generation of macro patterns is suppressed.

On the other hand, when the standard deviation of the particle size distribution based on the logarithm of the crystal grain size (μm) exceeds 0.80, coarse crystal grains are satisfied even when the above-mentioned average crystal grain size is satisfied. Is generated, and when a titanium alloy plate is used for a drum, a macro pattern is likely to occur.

The standard deviation of the particle size distribution based on the logarithm of the crystal particle size (μm) is preferably less than or equal to the threshold (0.35 × lnD −0.42) when the average crystal particle size is D (μm). ..

The average crystal grain size and standard deviation of the grain size distribution of the crystals of the metal structure of the titanium alloy plate can be measured and calculated as follows. Specifically, a cross section obtained by cutting a titanium alloy plate is chemically polished, and an electron backscatter diffraction method; EBSD (Electron Backscattering Diffraction Pattern) is used to cover a region of 1 to 2 mm × 1 to 2 mm in a region of 1 to 2 μm. Measure about 2 to 10 fields in step 1. Regarding the crystal grain size, the boundary of the orientation difference of 5 ° or more measured by EBSD is defined as the grain boundary, the range surrounded by this grain boundary is defined as the crystal grain, and the particle size equivalent to a circle from the area of the crystal grain (area A =). π × (particle size D / 2) ² ) is obtained, and the average value based on this number is taken as the average crystal grain size. In addition, the standard deviation σ in the lognormal distribution can be calculated from the crystal grain size distribution. At that time, the standard deviation σ of the distribution of the conversion value obtained by converting the circle-equivalent particle size D of each crystal grain into the natural logarithm lnD is obtained.
It is generally known that the crystal grain size distribution of a metal material follows a lognormal distribution. Therefore, in calculating the standard deviation of the particle size distribution as described above, the obtained particle size distribution may be standardized to a lognormal distribution, and the standard deviation may be calculated from the standardized lognormal distribution.

(12.3 collective organization)
<The area ratio of crystal grains whose angle formed by the α phase in the [0001] direction with respect to the plate thickness direction is 0 ° or more and 40 ° or less is 70% or more>
The crystal structure of the α phase of titanium has a hexagonal close-packed structure (hcp). Titanium having an hcp structure has a large anisotropy of physical properties depending on the crystal orientation. Specifically, titanium having an hcp structure has a high strength in a direction parallel to the [0001] direction (hereinafter, also referred to as a c-axis direction), and a low strength as it approaches a direction perpendicular to the c-axis direction. Therefore, even if the titanium alloy plate satisfies the particle size distribution of the crystal grains as described above, for example, when aggregates of crystals having different crystal orientations are generated, the workability between the two aggregates is different, so that the copper foil At the time of manufacturing a manufacturing drum, the workability at the time of polishing may be different. In this case, the obtained drum may be recognized as a macro pattern having a size close to that of crystal grains. Therefore, it is preferable to suppress the occurrence of macro patterns by accumulating the crystal orientations of the texture of the titanium alloy plate as much as possible.

Further, titanium having an hcp structure has high strength in a direction parallel to the c-axis direction. Therefore, when the surface perpendicular to the c-axis is polished, the pattern after polishing is unlikely to occur. From this point of view, the crystal orientation of the texture of the titanium alloy plate should be perpendicular to the polished surface, that is, the thickness direction perpendicular to the surface of the titanium alloy plate (normal direction of the plate surface: ND). It is preferable to arrange the c-axis of the crystal lattice of the titanium alloy plate so as to be parallel.

In the titanium alloy plate according to the present embodiment, the area ratios of the crystal grains having an angle θ formed by the normal direction (ND) of the plate surface and the c-axis of the α phase ([0001] direction) of 40 ° or less are all. It is 70% or more with respect to the area of the crystal grains of. The angle θ is the angle shown in FIG.
When the area ratio of crystal grains having an angle θ formed by the c-axis of the ND and the α phase of 40 ° or less is 70% or more, the crystal orientations are accumulated and the difference in crystal orientations between adjacent crystals is reduced. Can be done. As a result, the macro pattern can be suppressed. The area ratio of the crystal grains having an angle θ of 40 ° or less is preferably 72% or more with respect to the area ratio of all the crystal grains. The higher the area ratio, the better. Therefore, although the upper limit of the area ratio is not set, it is practically possible to manufacture up to about 95%.

The angle θ formed by the c-axis of the α phase with respect to the plate thickness direction can be calculated using the (0001) pole figure from the normal direction (ND) of the plate surface. (0001) The pole figure is obtained by chemically polishing the observation surface of the sample of the titanium alloy plate and analyzing the crystal orientation using EBSD. Specifically, for example, by scanning a region of 1 to 2 mm × 1 to 2 mm at intervals of 1 to 2 μm using EBSD, a crystal orientation map as shown in FIG. 5 can be obtained.
For example, the region G1 shown in white in FIG. 5 shows crystal grains having an angle θ formed by the c-axis of the ND and the α phase of 40 ° or less, and the region G2 shown in black is the c-axis of the α phase. Crystal grains with an angle θ formed with and less than 40 ° and less than 60 ° are shown, and the region G3 shown in gray shows crystal grains with an angle θ formed with the c-axis of the α phase of more than 60 ° and 90 ° or less. There is. Then, the (0001) pole figure can be drawn by the crystal orientation analysis. As shown in FIG. 6, in the (0001) pole diagram, the region R1 surrounded by the dotted line b1 is a region where the angle θ formed by the plate thickness direction (ND) and the c-axis of the crystal grain is 40 ° or less, and is a dotted line. The region R2 surrounded by b1 and the dotted line b2 is a region having an angle θ of more than 40 ° and less than 60 °, and the region outside the dotted line b2 is a region having an angle θ of 60 ° or more and 90 ° or less.

The area ratio of crystal grains having an angle θ formed by the thickness direction (ND) of the titanium alloy plate and the c-axis of the α phase of 40 ° or less can be calculated as follows. The cross section of the titanium alloy plate is chemically polished and crystal orientation analysis is performed using EBSD. For each of the lower surface of the titanium alloy plate and the central portion of the plate thickness, a region of 1 to 2 mm × 1 to 2 mm is measured in a step of 1 to 2 μm for about 2 to 10 visual fields. For the data, measurement point data in which the angle between the ND and the c-axis is 40 ° or less is extracted using OIM Analysis software manufactured by TSL Solutions. From the above, the area ratio of the crystal grains having an angle θ formed by the thickness direction (ND) of the titanium alloy plate and the c-axis of the α phase of 40 ° or less is calculated.

<Texture analysis of the pole map using the spherical harmonics method of the electron backscatter diffraction (EBSD) method in the (0001) pole map from the normal direction of the plate surface (expansion index = 16, Gaussian half width = 5 °) ) Has an aggregate structure in which the peak of the degree of integration calculated by) exists within 30 ° from the normal direction of the plate surface and the maximum degree of integration of the (0001) surface is 4.0 or more.

In the titanium alloy plate according to the present embodiment, in the (0001) pole diagram from the normal direction (ND) of the plate surface (rolled surface in the case of a rolled material), the peak of the degree of accumulation of crystal grains is the normal of the plate surface. It is preferable to have an texture that exists within 30 ° from the direction (TD) and has a maximum degree of integration of 4.0 or more. As a result, the c-axis of the crystal grains can be sufficiently integrated in the portion close to the thickness direction (ND) of the titanium alloy plate, and when the titanium alloy plate is used for the copper foil manufacturing drum, the difference in crystal orientation becomes large. The occurrence of the resulting pattern is further suppressed.
According to rolling and the like, the peak of the degree of accumulation of crystal grains tends to be inclined in the direction perpendicular to the final rolling direction (final rolling width direction (TD)). Therefore, when the final rolling direction is clear, the peak of the degree of accumulation of crystal grains is final from the normal direction (ND) of the plate surface in the (0001) pole diagram from the normal direction (ND) of the plate surface. It suffices to exist within 30 ° in the rolling width direction (TD).

(0001) The pole figure is obtained by chemically polishing the observation surface of the sample of the titanium alloy plate and analyzing the crystal orientation using EBSD. For example, as described above, a region of 1 to 2 mm × 1 to 2 mm can be scanned at intervals (steps) of 1 to 2 μm to draw a (0001) pole figure. At this time, the position with the highest contour line is the peak position of the degree of integration, and the value with the highest degree of integration among the peak positions is the maximum degree of integration.

FIG. 1 shows an example of a (0001) pole figure from the normal direction (ND) from the rolled surface of the titanium alloy plate according to the present embodiment. In FIG. 1, the detected pole points are accumulated according to the inclination in the final rolling direction (RD) and the final rolling width direction (TD), and contour lines of the degree of integration are drawn in the (0001) pole figure. Then, in FIG. 1, the portions where the contour lines are highest are the peaks P1 and P2 of the degree of accumulation of crystal grains. Therefore, in the present embodiment, the peaks P1 and P2 of the crystal grains are present within 30 ° from the ND (center), respectively. For example, in the case of peak P1, a in the figure is within 30 ° (as in P1 in FIG. 1, the peak position may deviate slightly from the TD direction, but deviation within 10 ° is allowed, and a is 30 ° or less. It should be within). Further, the maximum degree of integration is 4.0 or more. Usually, the maximum degree of accumulation is the degree of accumulation of peaks P1 or P2 of crystal grains.

On the other hand, in the (0001) pole diagram, when the peak of the degree of accumulation of crystal grains does not exist within 30 ° with respect to the final rolling width direction (TD), the crystal grains having different crystal orientations are likely to be adjacent to each other and are visible. Macro patterns are likely to occur. Specifically, for example, in a normal uniaxially rolled titanium hot-rolled plate, the degree of integration is usually at a portion where the c-axis of the hcp structure is tilted by about 35 to 40 ° in the final rolling width direction (TD) with respect to ND. A peak texture is formed. However, when the peak is at this position, the crystal orientation is distributed up to a position tilted by 15 to 20 °, so that crystal grains having different crystal orientations may be adjacent to each other, and a macro pattern is likely to occur.

The preferred maximum degree of integration is 4.0 or higher. As a result, the crystal orientations are sufficiently accumulated, and the difference in crystal orientations between adjacent crystals can be reduced. The maximum degree of integration is preferably 4.0 or more, but more preferably 5.0 or more, still more preferably 6.0 or more, for the purpose of further suppressing the occurrence of macro patterns.
The larger the maximum degree of integration is, the more preferable it is. Therefore, the upper limit is not limited, but for example, when the crystal orientation is controlled by hot rolling, the upper limit may be about 15 to 20.

(0001) The degree of accumulation of a specific orientation in the pole map indicates how many times the frequency of existence of crystal grains having that orientation is higher than that of a structure having a completely random orientation distribution (degree of integration 1). .. This degree of integration can be calculated by using the Texture analysis of the pole figure using the spherical harmonics method of the electron backscatter diffraction (EBSD) method (expansion index = 16, Gauss half width = 5 °). Specifically, a cross section obtained by cutting a titanium alloy plate is chemically polished, and a region of 1 to 2 mm × 1 to 2 mm is measured in a step of 1 to 2 μm in a field of about 2 to 10 by the EBSD method. The data is calculated by Texture analysis of the pole figure using the spherical harmonic method using OIM Analysis software manufactured by TSL Solutions.

(12.4 twins)
Titanium may undergo twinning deformation during plastic deformation. Twin deformation depends on the crystal grain size as well as the chemical composition, and the larger the grain size, the more likely it is to occur. Therefore, the appearance of crystal grain distribution may become uniform due to the formation of twins.
On the other hand, when twinning deformation occurs, the difference in crystal orientation becomes large, and crystal grains having significantly different crystal orientations are adjacent to each other, and the abrasiveness changes at the boundary, and the crystal is recognized as a pattern. Therefore, it is preferable to suppress twins as much as possible.

Specifically, the titanium alloy plate according to the present embodiment has twin grain boundaries with respect to the total grain boundary length of the plate thickness cross section at a position of 1/4 of the plate thickness from the surface when observing the cross section in the plate thickness direction. The length ratio is preferably 5.0% or less. As a result, the macro pattern caused by twinning can be reduced to an unrecognizable level. The ratio of the twin grain boundary length to the total grain boundary length is more preferably 3.0% or less, still more preferably 1.0% or less. The lower limit of the above ratio may be 0%, but it is difficult to completely eliminate twins because twins are inevitably deformed by processing such as straightening of a titanium alloy plate. In order to reduce twins, it is important to reduce the amount of correction. For example, it is effective to make the finished plate shape as flat as possible.

In calculating the above ratio, the total grain boundary length and the twin grain boundary length of the plate thickness cross section can be obtained as follows. First, the observation cross section (thickness direction cross section) of the sample of the titanium alloy plate is chemically polished, and the crystal orientation is analyzed using the electron backscatter diffraction method. A region of 1 to 2 mm x 1 to 2 mm at a position 1/4 of the thickness of the titanium alloy plate of the sample is scanned at intervals of 1 to 2 μm, and a reverse pole map is used using OIM Analysis software manufactured by TSL Solutions. (IPF: analyze color figure) is created. At that time, the rotation axis and crystal orientation (rotation angle) of (10-12) twins, (10-11) twins, (11-21) twins, and (11-22) twins generated in titanium. Within 2 ° from the theoretical value is regarded as the twin interface (for example, in the case of (10-12) twin, the theoretical values of the rotation axis and the crystal orientation difference (rotation angle) are <11-20> and 85 °, respectively). .. Then, the grain boundary having a crystal orientation difference (angle of rotation) of 2 ° or more is defined as the total grain boundary length, and the ratio of the twin grain boundary length to the total crystal grain boundary length is calculated. The twin grain boundaries are observed at a position of 1/4 of the plate thickness from the surface because the position can sufficiently represent the structure of the titanium alloy plate. Further, the surface of the titanium alloy plate may not be able to sufficiently represent the structure due to polishing or the like.

(1.3 Surface hardness)
The surface hardness (Vickers hardness) of the surface of the titanium alloy plate to be the drum surface is not particularly limited, but is preferably HV110 or higher. As a result, when a drum is manufactured using a titanium alloy plate and the surface is polished, uniform polishing becomes possible, and macro patterns can be further suppressed. The surface hardness (Vickers hardness) of the titanium alloy plate is more preferably HV112 or higher, and even more preferably HV115 or higher.
Further, the upper limit of the surface hardness (Vickers hardness) of the surface of the titanium alloy plate to be the drum surface is not particularly limited, but if the surface hardness exceeds HV350, the number of polishings increases and it takes time. , Drum productivity is reduced. Therefore, it is preferably 350 HV or less. It is more preferably 300 HV or less, still more preferably 250 HV or less. Further, when the amount of processing required for straightening the titanium alloy plate is sufficiently reduced, the HV is preferably 160 or less. It is more preferably HV155 or less, still more preferably HV150 or less.

The surface hardness of the titanium alloy plate is measured at 3 to 5 points with a load of 1 kg using a Vickers hardness tester in accordance with JIS Z 2244: 2009 after polishing the surface of the titanium alloy plate to a mirror surface, and the average thereof. Can be a value.

(1.4 thickness)
The thickness of the titanium alloy plate according to the present embodiment is not particularly limited, and can be appropriately set according to the application, specifications, and the like of the drum to be manufactured. When used as a material for a copper foil manufacturing drum, the plate thickness decreases with the use of the copper foil manufacturing drum. Therefore, the thickness of the titanium alloy plate is preferably 4.0 mm or more, even if it is 6.0 mm or more. Good. The upper limit of the thickness of the titanium alloy plate is not particularly limited, but is, for example, 15.0 mm.

In the present embodiment described above, the chemical composition of the titanium alloy plate is set so as to suppress grain growth and reduce deformation after hot rolling, and the crystals are not only fine but also predetermined. A crystal having a uniform size that fits within the standard deviation, a crystal structure containing an α phase having a hexagonal close-packed structure, and an angle formed by the α phase in the [0001] direction with respect to the plate thickness direction of 0 ° or more and 40 ° or less. The area ratio of the grains is 70% or more. Therefore, it is possible to sufficiently suppress the occurrence of macro patterns when used in a drum for producing copper foil.

Further, when the titanium alloy plate according to the present embodiment contains Al of more than 1.8% and 7.0% or less, the Young's modulus of the titanium alloy plate is improved. As a result, in the production of the copper foil production drum, the shrinkage fit of the titanium alloy plate onto the surface of the core material is improved, and the productivity of the copper foil production drum is improved.

FIG. 2 shows a photograph of a macro pattern on the surface of a titanium alloy plate as an example. As shown in FIG. 2, the “macro pattern” refers to a pattern in which parts having different colors are generated in a streak shape with a length of several mm in parallel with the rolling direction (for reference, the macro pattern in FIG. 3 and FIG. 2). The figure that emphasizes the macro pattern is shown so that the position of can be seen). If a large amount of such a pattern is generated, the pattern is transferred to the copper foil to be finally produced.
The macro pattern is generated in the copper foil manufacturing process, but regarding the susceptibility of the macro pattern to the titanium alloy plate (the rate of occurrence of the macro pattern under the same conditions), the surface of the titanium alloy plate is made of # 800 emery paper. It can be evaluated by observing the surface by corroding the surface with a solution of 10% nitric acid and 5% hydrofluoric acid.

<Copper foil manufacturing drum>
As described above, the titanium alloy plate according to the present embodiment can sufficiently suppress the occurrence of macro patterns when used in a drum for producing copper foil, and is suitable as a material for a drum for producing copper foil.
With reference to FIG. 8, the copper foil manufacturing drum 20 according to the present embodiment is a part of the electrodeposition drum, and is a cylindrical inner drum 21 and a titanium alloy plate adhered to the outer peripheral surface of the inner drum 21. 22 and a welded portion 23 provided at a butt portion of the titanium alloy plate 22, and the titanium alloy plate 22 is the titanium alloy plate according to the present embodiment described above.
That is, the copper foil manufacturing drum 20 according to the present embodiment is a copper foil manufacturing drum manufactured by using the titanium alloy plate according to the present embodiment. Since the copper foil manufacturing drum 20 according to the present embodiment uses the titanium alloy plate according to the present embodiment on the surface of the drum on which the copper foil is deposited, the occurrence of macro patterns is suppressed and high quality copper foil is produced. Can be manufactured.
The size of the copper foil manufacturing drum according to the present embodiment is not particularly limited, but the diameter of the drum is, for example, 1 to 5 m.
The inner drum 21 may be a known one, and the material thereof may not be a titanium alloy plate, for example, mild steel or stainless steel.
The titanium alloy plate 22 is wound around the outer peripheral surface of the cylindrical inner drum 21 and welded to the butt portion to be adhered to the inner drum. Therefore, the welded portion 23 exists in the butt portion.

In the welded portion of the copper foil manufacturing drum according to the present embodiment, the metal structure has an α phase of 98.0% or more in volume fraction, and the particle size number conforms to JIS G 0551: 2013, which is 6 or more and 11 or less. Is. The particle size number is preferably 7 or more and 10 or less.
When the grain size (crystal grain size) of the crystal grains of the metal structure of the welded portion is coarse, the crystal grains themselves become a pattern, and the pattern is transferred to the copper foil. The fineness of the crystal grains in the metal structure of the welded portion suppresses the generation of patterns caused by the crystal grains.

The grain size number of the crystal grain of the metal structure of the welded portion can be measured by a comparative method, a counting method and a cutting method according to JIS G 0551: 2013.

The welded portion 23 of the copper foil manufacturing drum 20 according to the present embodiment has, for example, the following metal structure.
The metallographic structure of the weld is mainly α phase, that is, mainly contains α phase. The β phase corrodes in preference to the α phase. Therefore, from the viewpoint of achieving uniform corrosion and suppressing the generation of macro patterns, it is preferable that the β phase is small. On the other hand, when a small amount of β phase is present, crystal grain growth during heat treatment can be suppressed, so that a uniform and fine crystal grain size can be obtained. From this point of view, it is desirable that the volume fraction of the β phase of the metal structure of the welded portion is 2.0% or less. In this case, the rest of the metal structure of the titanium alloy plate is the α phase. The volume fraction of the β phase is preferably 1.0% or less, and more preferably, the texture of the welded portion is α single phase. The volume fraction of the α phase in the metal structure of the welded portion according to the present embodiment is preferably 98.0% or more, more preferably 99.0% or more, and further preferably 100%.

The volume fraction of each phase constituting the metal structure of the welded portion can be obtained by the same method as that of the base metal portion.

Further, if the hardness difference between the welded portion and the drum base material is large, a step may occur during polishing. Therefore, the difference in hardness (Vickers hardness) between the welded portion and the drum base material is preferably ± 25 or less. More preferably, it is ± 15 or less. As a result, when a drum is manufactured using a titanium alloy plate and the surface is polished, uniform polishing becomes possible, and macro patterns can be further suppressed. The hardness of the welded portion is, for example, HV110 or higher, more preferably HV112 or higher, and even more preferably HV115 or higher.

The hardness of the welded part is measured at 3 to 5 points with a load of 1 kg using a Vickers hardness tester in accordance with JIS Z 2244: 2009 after polishing the surface of the welded part until it becomes a mirror surface, and the average value is used. be able to.

Further, the difference between the crystal grain size of the formed welded portion and the crystal grain size of the titanium alloy plate (difference in particle size number) is preferably −1.0 or more and 1.0 or less. By reducing the difference in crystal grain size between the welded portion and other portions, the generation of macro patterns is more reliably suppressed.

<2. Method for manufacturing titanium alloy plate according to this embodiment>
The titanium alloy plate according to the present embodiment described above may be produced by any method, and for example, it can be produced by the method for producing a titanium alloy plate according to the present embodiment described below.
A preferred method for manufacturing a titanium alloy plate according to this embodiment is
(I) A first step (heating step) of heating a titanium alloy having the above-mentioned chemical composition to a temperature of 750 ° C. or higher and 950 ° C. or lower.
(II) A second step (rolling step) of rolling to obtain a titanium alloy plate after the heating step, and
(III) The third step (annealing step) of annealing the titanium alloy after the rolling step and
Have. Hereinafter, each step will be described.

(2.1 Preparation of titanium alloy plate material)
First, the material of the titanium alloy plate is prepared prior to each of the above-mentioned steps. As the material, those having the above-mentioned chemical composition can be used, and those produced by a known method can be used. For example, an ingot is produced from titanium sponge by various melting methods such as a vacuum arc remelting method, an electron beam melting method, and a hearth melting method such as a plasma melting method. Next, a material can be obtained by hot forging or rolling the obtained ingot at a temperature in the α-phase high temperature region or the β-phase single-phase region. The material may be subjected to pretreatment such as cleaning treatment and cutting, if necessary. Further, when a rectangular slab shape that can be hot-rolled is manufactured by the hearth melting method, it can be directly subjected to the following first step and second step (heating, hot rolling) without hot forging or the like. Good.

(2.2 First step)
This step is a heating step performed prior to hot rolling of the titanium material. In this step, the material of the titanium alloy plate is heated to a temperature of 750 ° C. or higher and 950 ° C. or lower. When the heating temperature is 750 ° C. or higher, it is possible to prevent the titanium alloy plate from cracking in the hot rolling in the second step. Further, when the heating temperature is 950 ° C. or lower, it is possible to prevent the formation of a texture (T-texture) in which the c-axis of the hcp structure is oriented in the plate width direction in the hot rolling in the second step.
On the other hand, when the heating temperature is less than 750 ° C., for example, when coarse particles are generated in hot forging, casting, etc., the titanium alloy plate is cracked from the coarse particles in the hot rolling in the second step. May occur.

Further, when the heating temperature exceeds 950 ° C., a coarse texture (T-texture) in which the c-axis of the hcp structure is oriented in the plate width direction is generated in the hot rolling in the second step. In this case, a structure in which the angle formed by the α phase in the [0001] direction with respect to the plate thickness direction as described above is 0 ° or more and 40 ° or less and the area ratio of the crystal grains is 70% or more cannot be obtained. When the heating temperature is 950 ° C. or lower, the formation of T-texture can be prevented. Therefore, the heating temperature is 950 ° C. or lower. The heating temperature is preferably β transformation point or lower, more preferably 900 ° C. or lower or (β transformation point −10 ° C.) or lower.
Further, in the (0001) pole diagram from the normal direction of the plate surface, the peak of the degree of accumulation of crystal grains exists within 30 ° with respect to the direction of the final rolling width, and the maximum degree of integration is 4.0 or more. In order to obtain a structure, the heating temperature is preferably 900 ° C. or lower, and particularly when the Al content is 3.0% or less, the heating temperature is preferably 880 ° C. or lower.

In the present embodiment, the “β transformation point” means the boundary temperature at which the α phase begins to be generated when the titanium alloy is cooled from the β phase single phase region. The β transformation point can be obtained from the phase diagram. The phase diagram can be obtained, for example, by the CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) method. Specifically, the phase diagram of the titanium alloy is obtained by the CALPHAD method using Thermo-Calc, which is an integrated thermodynamic calculation system of Thermo-Calc Storage AB, and a predetermined database (TI3), and the β transformation point is determined. Can be calculated.

(2.3 Second step)
In this step, the material of the heated titanium alloy plate is rolled (hot rolling). Then, in this step, the total reduction rate may be 80% or more, and the ratio of the rolling reduction rate at 200 ° C. or higher and 650 ° C. or lower to the total reduction rate may be 5% or more and 70% or less. preferable. As a result, the crystal grains are uniformly miniaturized as described above, and an aggregate structure in which the c-axis of the hcp structure is highly integrated along the plate thickness direction can be obtained. The hot rolling start temperature in this step is basically the above heating temperature.
When the total reduction rate is 80% or more, the coarse particles generated in hot forging, casting, etc. can be sufficiently finely divided, and T-texture can be prevented from occurring. If the total reduction rate is less than 80%, the structure generated in hot forging, casting, etc. may remain, and coarse grains may be formed or T-texture may occur. When such a structure occurs, a macro pattern is generated in the produced drum.
When the Al content is 3.0% or less, the total reduction rate in this step is preferably 85% or more. Further, the reduction rate is determined according to the required product size and the characteristics of the manufacturing mill because the higher the reduction rate, the better the structure.

Further, in the titanium alloy manufacturing method according to the present embodiment, the ratio of the rolling reduction rate of the titanium alloy plate at 200 ° C. or higher and 650 ° C. or lower to the total reduction rate is 5% or more and 70% or less. Is preferable. In particular, when the Al content is low (for example, 3.0% or less), it is preferable to satisfy the above.
When the ratio of the rolling reduction rate of the titanium alloy plate at 200 ° C. or higher and 650 ° C. or lower is less than 5% of the total reduction rate, such as when the total rolling is performed at more than 650 ° C., the reduction amount in this temperature range. Is insufficient, recovery occurs during subsequent cooling, and a portion with a small amount of strain occurs. Therefore, the heat treatment after hot rolling increases the variation in crystal grain size. Variations in crystal grain size are likely to occur especially when the Al content that suppresses crystal grain growth is small.
Further, by setting the ratio of the rolling reduction ratio of the titanium alloy plate at 200 ° C. or higher and 650 ° C. or lower to 5% or more and 70% or less, the crystal structure includes the α phase which is a hexagonal close-packed structure, and the plate thickness. In a structure in which the angle formed by the α phase in the [0001] direction with respect to the direction is 0 ° or more and 40 ° or less and the area ratio of the crystal grains is 70% or more, and / or in the (0001) pole view from the normal direction of the plate surface. It becomes easy to obtain a texture in which the peak of the degree of accumulation of crystal grains exists within 30 ° with respect to the final rolling width direction and the maximum degree of integration is 4.0 or more.
On the other hand, when the total rolling is performed at a temperature of less than 200 ° C. and the ratio of the rolling reduction rate of the titanium alloy plate at 200 ° C. or higher and 650 ° C. or lower is less than 5% of the total rolling reduction rate, the plate shape is not good. It will be stable. In this case, the amount of processing in the subsequent straightening becomes large, strain is introduced, the difference in the amount of strain becomes large between the straightened portion and the other portion, and the variation in crystal grain size becomes large in the subsequent heat treatment. Furthermore, if straightening is performed after heat treatment, strain affects and only that portion is likely to be corroded, which may cause a macro pattern. The ratio of the rolling reduction rate of the titanium alloy plate at 200 ° C. or higher and 650 ° C. or lower to the total reduction rate is preferably 10% or more, more preferably 15% or more.

On the other hand, if the ratio of the rolling reduction rate of the titanium alloy plate at 200 ° C. or higher and 650 ° C. or lower exceeds 70% of the total rolling reduction rate, such as when the total rolling is performed at 650 ° C. or lower, the plate shape is not good. It will be stable. In this case, the amount of processing in the subsequent straightening becomes large, strain is introduced, the difference in the amount of strain becomes large between the straightened portion and the other portion, and the variation in crystal grain size becomes large in the subsequent heat treatment. Furthermore, if correction is performed after heat treatment, strain affects and only that portion is likely to be corroded, which may cause a macro pattern.
Therefore, the ratio of the rolling reduction rate of the titanium alloy plate at 200 ° C. or higher and 650 ° C. or lower is preferably 70% or less of the total reduction rate. It is more preferably 65% or less, still more preferably 60% or less.

The surface temperature of the titanium alloy plate at the completion of hot rolling in this step is preferably 200 ° C. or higher. By setting the surface temperature of the titanium alloy plate at the completion of hot rolling to 200 ° C or higher, it is possible to prevent the shape of the titanium alloy plate from becoming unstable, and it is possible to reduce the amount of processing due to subsequent straightening. it can. As a result, the amount of strain introduced into the titanium alloy plate is reduced, and the variation in crystal grain size that may occur in the subsequent heat treatment is reduced. In addition, when strain is introduced, only that part is easily corroded and may cause a macro pattern, but it can be corrected by setting the surface temperature of the titanium alloy plate at 200 ° C or higher when hot rolling is completed. The amount of processing at the time can be reduced, the amount of strain introduced into the titanium alloy plate is reduced, and the macro pattern can be suppressed. The surface temperature of the titanium alloy plate at the completion of hot rolling is preferably 300 ° C. or higher.

Further, in this step, the rolling may be unidirectional rolling in which the titanium alloy plate is stretched in the longitudinal direction, but in addition to rolling in the longitudinal direction, rolling may be performed in a direction orthogonal to the longitudinal direction. Good. Thereby, in the obtained titanium alloy plate, the degree of integration of the texture can be further increased.
Specifically, when the rolling reduction rate in the final rolling direction is L (%) and the rolling reduction rate in the direction orthogonal to the final rolling direction is T (%), the L / T is 1.0. It is preferably 10.0 or less. Thereby, in the obtained titanium alloy plate, the degree of integration of the texture can be further increased. The L / T is more preferably 1.0 or more and 5.0 or less.

In this step, when rolling at 200 ° C. or higher and 650 ° C. or lower, the titanium alloy plate may be held for a certain period of time and waited for cooling.

In the method for producing a titanium alloy plate according to the present embodiment, it is preferable that the titanium alloy plate is not reheated and rolled during the second step. As a result, the strain generated in rolling is prevented from being released by reheating, and the strain can be stably applied to the titanium alloy plate. As a result, the degree of integration of the texture of the titanium alloy plate can be increased, and partial abnormal grain growth during heat treatment, which will be described later, can be suppressed.

After the second step, cold rolling may be performed. Cold rolling is rolling at a temperature of 200 ° C. or lower, and may be performed by unidirectional rolling or cross rolling. The reduction rate is preferably 10% or more. By setting the reduction ratio to 10% or more, strain can be introduced uniformly, and variations in crystal grain size that may occur in the subsequent heat treatment can be reduced.
When cold rolling is performed, the oxide scale on the surface of the titanium alloy plate after hot rolling is removed in advance. The oxidation scale may be removed by, for example, shot blasting, pickling following shot blasting, or machining such as cutting. If necessary, annealing may be performed at a temperature below the β transformation point before removal of the oxidation scale. Such annealing is preferably performed at (β transformation point −50) ° C. or lower.
When cold rolling is performed, if the Al content of the titanium alloy plate is too large, the cold ductility is poor and the titanium alloy plate may crack. Therefore, the Al content of the titanium alloy plate in the case of cold rolling is preferably 3.5% or less.
Further, when the ratio of the twin grain boundary length to the total grain boundary length is reduced, it is preferable not to perform cold rolling.

(2.4 Third step)
In this step, the titanium alloy plate is heat-treated (annealed) at a temperature of 600 ° C. or higher and β transformation point ° C. or lower for 20 minutes or longer. As a result, the unrecrystallized grains can be precipitated as fine recrystallized grains, and the crystals in the metal structure of the obtained titanium alloy plate can be made uniform and fine. As a result, the occurrence of macro patterns can be suppressed more reliably.

Specifically, by heat-treating the titanium alloy plate at a temperature of 600 ° C. or higher for 20 minutes or longer, unrecrystallized grains can be sufficiently precipitated as recrystallized grains. The annealing temperature is preferably 650 ° C. or higher. From the viewpoint of suppressing coarsening of crystal grains, it is preferable to set the annealing temperature to β transformation point or lower. More preferably, it is 800 ° C. or lower.
The upper limit of the annealing time is not particularly limited, but is, for example, 5 hours or less. In particular, when the Al content having the effect of suppressing crystal grain growth is small, the annealing time is preferably 90 minutes or less from the viewpoint of suppressing coarsening of crystal grains.

The heat treatment may be performed in an air atmosphere, an inert atmosphere, or a vacuum atmosphere. However, when the oxide scale is formed on the titanium alloy plate, the oxide scale is removed. The removal of the oxide scale is not particularly limited, and may be performed by, for example, shot blasting, pickling following shot blasting, or machining such as polishing or cutting. However, shot blasting may cause strain to be introduced into the titanium alloy plate, so it is better to avoid removing the oxide scale by shot blasting.
Further, the annealing method is not particularly limited, and may be a continuous heating method or a batch heating method.

(2.5 Post-treatment process)
Examples of the post-treatment include removal of oxide scale and the like by pickling and cutting, cleaning treatment, and the like, which can be appropriately applied as needed. Alternatively, as a post-treatment, a straightening process of the titanium alloy plate may be performed. The straightening process can be performed by, for example, vacuum creep straightening (VCF).
The method for manufacturing the titanium alloy plate according to the present embodiment has been described above.

Next, a method for manufacturing the copper foil manufacturing drum according to the present embodiment will be described.
A method for manufacturing a copper foil manufacturing drum according to the present embodiment is a titanium wire for welding (titanium for welding according to the present embodiment) in which two adjacent ends of the titanium alloy plate according to the present embodiment processed into a cylindrical shape are described later. It has a process (welding process) of welding using a wire rod).
The processing of the titanium alloy plate into a cylindrical shape, welding conditions, and the like can be performed by known methods.
At the time of welding, for example, two adjacent ends of a titanium alloy plate processed into a cylindrical shape are built-up welded using the titanium wire rod for welding described above to form a welded portion (build-up welded portion). Here, since the welded portion is processed cold or warm, it is preferable to pre-fill the built-up portion. The pre-filled thickness can be, for example, 10 to 50% of the thickness of the titanium alloy plate.
Further, the build-up welded portion may be pressed cold or warm at 200 ° C. or lower. As a result, the solidified structure of the build-up weld can be made into a uniform fine equiaxed structure. The reduction rate is preferably 10% or more and 50% or less in order to prevent the generation of straw due to a high processing rate and to ensure that the solidified structure has a uniform fine equiaxed structure.
Further, heat treatment (annealing) may be performed after welding. The heat treatment can be performed, for example, at a temperature of 500 ° C. or higher and 850 ° C. or lower for 1 minute or longer and 10 minutes or shorter. By performing the heat treatment at 850 ° C. or lower for 10 minutes or less, it is possible to prevent coarsening of the crystal grains and coarsening of a part of the crystal grains, and a uniform fine crystal structure can be obtained.

Next, the titanium wire for welding used for manufacturing the copper foil manufacturing drum according to the present embodiment will be described.

<Titanium wire for welding>
The titanium wire for welding according to the present embodiment can be used for manufacturing a titanium drum for producing copper foil, and more specifically, for welding adjacent ends of a titanium alloy plate bent into a cylindrical shape. Used for.

The titanium wire for welding according to this embodiment is based on mass%.
One or more selected from the group consisting of Sn, Zr and Al: 0.2% or more and 6.0% or less in total O: 0.01% or more and 0.70% or less,
N: 0.100% or less,
C: 0.080% or less,
H: 0.015% or less, and Fe: 0.500% or less, including
The balance preferably has a chemical composition containing Ti and impurities.

The content of one or more selected from the group consisting of Sn, Zr and Al is 0.2% by mass or more and 6.0% by mass or less in total. As a result, the metal structure of the obtained welded portion can be mainly composed of α phase, and the formation of β phase can be suppressed, so that the corrosion resistance of the welded portion can be improved. Furthermore, the crystal grains in the metal structure of the obtained welded portion can be made sufficiently fine, and the generation of macro patterns caused by the crystal grains can be suppressed.

On the other hand, when the content of one or more selected from the group consisting of Sn, Zr and Al is less than 0.2% by mass in total, coarse particles are formed in the crystal grains in the metal structure of the obtained welded portion. May occur, and the occurrence of macro patterns cannot be suppressed. The content of one or more selected from the group consisting of Sn, Zr and Al is preferably 0.3% by mass or more in total, and more preferably 0.4% by mass or more in total.

Further, when the content of one or more selected from the group consisting of Sn, Zr and Al exceeds 6.0% by mass in total, it is obtained due to the adverse effect caused by the excessive content of Sn, Zr and Al described above. It is not possible to suppress the occurrence of macro patterns in the welded parts. The content of one or more selected from the group consisting of Sn, Zr and Al is preferably 5.5% by mass or less in total, and more preferably 5.0% by mass or less in total.

Among the above-mentioned elements, Sn is a neutral element, and is an element capable of suppressing the growth of crystal grains in the welded portion by being contained in the titanium wire for welding. In order to stably suppress the growth of crystal grains, the Sn content is preferably 0.2% by mass or more, and more preferably 0.3% by mass or more.
On the other hand, if Sn is added excessively, it may segregate in the longitudinal direction of the titanium wire for welding depending on the chemical composition, and a macro pattern derived from the concentration may be formed in the bead welded portion. Therefore, the Sn content is preferably 6.0% by mass or less, and more preferably 5.5% by mass or less.

Zr is also a neutral element, and is an element that can suppress the growth of crystal grains by being contained in the titanium wire for welding. In order to stably suppress the growth of crystal grains, the Zr content is preferably 0.2% by mass or more, and more preferably 0.3% by mass or more.
On the other hand, when Zr is excessively added, the α + β region near the transformation temperature becomes wide depending on the chemical composition, and the β phase is likely to be precipitated in the heat treatment during the production of the copper foil production titanium drum. Further, as a result of a difference in surface strength due to solidification segregation, a macro pattern may occur during surface polishing of a copper foil manufacturing titanium drum. Therefore, the Zr content is preferably 5.5% by mass or less, and more preferably 5.0% by mass or less.

Al is an α-stabilizing element, and like Sn and Zr, it can suppress the growth of crystal grains by being contained in the titanium wire for welding, and the titanium wire for welding and the welding formed by using the same. Contributes to the improvement of the strength of the part. In order to stably suppress the growth of crystal grains, the Al content is preferably 0.2% by mass or more, and more preferably 0.3% by mass or more.
On the other hand, if the Al content is excessive, the increase in high-temperature strength becomes large depending on the chemical composition, and the reaction force becomes too large in the processing of the solidified structure (welded portion) of the titanium wire for welding before heat treatment, resulting in processing cracks. In addition, the difference in hardness between the welded portion and the base material becomes large, and a step may occur during polishing and surface preparation of the copper foil manufacturing titanium drum. Therefore, the Al content is preferably 5.0% by mass or less, more preferably 4.5% by mass or less.

As described above, Al is an element that can contribute to the improvement of the strength of the welded portion, and increases the hardness of the welded portion. Therefore, when suppressing the increase in hardness of the welded portion, it is preferable to include it together with Sn and / or Zr.
In such a case, for example, the total content of Sn and Al is 0.2% by mass or more and 6.0% by mass or less, preferably 0.3% by mass or more and 5.5% by mass or less. Further, for example, the total content of Zr and Al is 0.2% by mass or more and 6.0% by mass or less, preferably 0.3% by mass or more and 5.5% by mass or less.

The above-mentioned Sn, Zr and Al may be contained in the above-mentioned amounts in total, and any one or two may not be contained in the titanium wire for welding.

O is an α-stabilizing element, and can improve the strength at room temperature while suppressing an increase in high-temperature strength, and can improve the hardness of the welded portion. In order to obtain this effect, the O content is 0.01% by mass or more. From the viewpoint of controlling the hardness of the welded portion, the O content is preferably 0.015% by mass or more, more preferably 0.02% by mass or more.
On the other hand, if the O content exceeds 0.70% by mass, cracks will occur in the build-up process during welding. Therefore, the O content is 0.70% by mass or less. The O content is preferably 0.60% by mass or less, more preferably 0.50% by mass or less.

At least a part of O is present in the titanium wire for welding as an oxide of granular Ti, Sn, Zr and / or Al, for example, as TIO ₂ , SnO, SnO ₂ , ZrO ₂ , Al ₂ O ₃ . It is preferable to do so. These oxides are dissociated by an arc at the time of welding, and the dissociated O forms an oxide film at the welded portion, suppresses local contact with the arc, and stabilizes the welded portion to homogenize the welded portion. Thereby, the build-up shape and workability can be improved at the time of welding. O is considered to dissolve uniformly in the drum weld.

More specifically, the peak intensities of α-titanium obtained by the X-ray diffraction method for the titanium wire for welding are A, TiO ₂ (110), ZrO ₂ (111), SnO ₂ (110) and Al ₂ O ₃ ( When the total peak intensity of 104) is B, the B / A (line intensity ratio) is preferably 0.01 or more. As a result, a sufficient amount of oxide is contained in the titanium wire for welding, and the above-mentioned effects can be sufficiently obtained. The B / A is more preferably 0.015 or more and 0.10 or less, and further preferably 0.02 or more and 0.09 or less.

The X-ray diffraction of the titanium wire for welding according to the present embodiment is carried out for a cross section perpendicular to the longitudinal direction using a Cu tube in a current of 40 mA, a voltage of 40 kV, and a range of 10 to 110 ° in the range of 2θ. The measurement is carried out at intervals of 0.01 ° at 1 s / point, and can be performed by rotating the sample 360 ° at each measurement point.

Fe is an element that reinforces the β phase. Since the formation of macro patterns is affected by a large amount of β-phase precipitation in the welded portion, the upper limit of the Fe content in the titanium wire for welding is set to 0.500%. The Fe content is preferably 0.100% or less, more preferably 0.080% or less.

N, C, and H are elements that reduce ductility and processability when contained in large amounts. Therefore, the N content is limited to 0.100% or less, the C content is limited to 0.080% or less, and the H content is limited to 0.015% or less.
N, C, and H are impurities, and the lower the content thereof, the more preferable. However, these elements may be mixed in during the production process, and the lower limit of the substantial content may be 0.0001% for N, 0.0005% for C, and 0.0005% for H.

The balance of the chemical composition of the titanium wire for welding according to the present embodiment contains titanium (Ti) and impurities, and may consist of Ti and impurities. Specifically, the impurities are Cl, Na, Mg, Si, Ca mixed in the refining step, Cu, Mo, Nb, Ta, V and the like mixed in from scrap. When these impurity elements are contained, the content thereof is, for example, 0.10% by mass or less, and if the total amount is further 0.50% by mass or less, there is no problem.

The wire diameter of the titanium wire for welding according to the present embodiment is not particularly limited, and is, for example, 0.8 mm or more and 3.4 mm or less.
The cross-sectional shape of the titanium wire for welding according to the present embodiment is not particularly limited as long as it can be used for welding, and may be any shape.

The titanium wire for welding can be produced by cold, warm and hot plastic working such as hole die wire drawing, roll die wire drawing, caliber rolling and the like, and powder metallurgy.

As described above, according to the present embodiment, by incorporating an appropriate amount of one or more selected from the group consisting of Sn, Zr and Al in the titanium wire for welding, the structure of the welded portion is mainly composed of α phase, and crystals are formed. The grains can be refined. Further, the hardness of the welded portion can be controlled by containing an appropriate amount of O in the titanium wire for welding. As a result, in the copper foil manufacturing titanium drum, the generation of macro patterns caused by the welded portion is suppressed.

In particular, when granular oxides of Ti, Sn, Zr and / or Al are contained in the titanium wire for welding, the method of incorporating the oxide in the wire by powder metallurgy or the oxide is attached to the surface of the bar and the wire is drawn. As a result, a titanium wire for welding can be produced by a method of crimping an oxide to the surface, a method of adhering an oxide to the surface of a rod, vacuum annealing at 750 to 1000 ° C., and diffusion bonding. There is also a method of manufacturing titanium wire rods for welding by inserting powdered oxides into a hollow titanium tube, but the distribution of oxides tends to vary, which contributes to composition fluctuation in the welded part. The hardness and crystal grain size of the same part will fluctuate. Therefore, in the present embodiment, the method of inserting the powdery oxide into the titanium tube is not adopted and is excluded from the target.

Hereinafter, embodiments of the present invention will be specifically described with reference to examples. The examples shown below are merely examples of the present invention, and the present invention is not limited to the following examples.

1. 1. Production of Titanium Alloy Plate First, ingots having the chemical compositions shown in Tables 1 and 2 were prepared by a vacuum arc remelting method, and hot forging was performed to obtain a material for a titanium alloy plate having a predetermined composition.

Next, the material of the obtained titanium alloy plate was heated to the temperatures shown in Tables 3 and 4 (first step), and hot-rolled under the conditions shown in Tables 3 and 4 (second step). ). In the table, "ratio of rolling reduction rate of 200 to 650 ° C." refers to the ratio of rolling reduction rate of titanium alloy plate at 200 ° C. or higher and 650 ° C. or lower to the total rolling reduction rate, and is "rolling ratio (L / T)". "Shows the L / T value when the rolling reduction rate in the final rolling direction is L (%) and the rolling reduction rate in the direction orthogonal to the final rolling direction is T (%). Further, in each of the invention examples and comparative examples shown in Tables 1 and 2, hot rolling was temporarily stopped in order to roll the titanium alloy plate at 200 ° C. or higher and 650 ° C. or lower, except for Comparative Example 1. After waiting for cooling to 650 ° C. or lower, hot rolling was restarted.
For some examples, pre-annealing and cold rolling were performed.

Next, heat treatment was performed at the temperatures and times shown in Tables 3 and 4 under an air atmosphere (third step) to obtain a titanium alloy plate having a thickness of 8.0 to 15.0 mm.

2. Analysis / Evaluation The following items were analyzed and evaluated for the titanium alloy plates according to each invention example and comparative example.

2.1 Crystal grain size The average crystal grain size D and the standard deviation of the grain size distribution of the crystals of the metal structure of the titanium alloy plate according to each invention example and comparative example were measured and calculated as follows. The cross section of the cut titanium alloy plate was measured in 10 fields in 2 μm steps in a 2 mm × 2 mm region using chemical abrasive paper and electron backscatter diffraction method. After that, for the crystal grain size, the circle-equivalent particle size (area A = π × (particle size D / 2) ² ) was obtained from the crystal grain area measured by EBSD, and the average value based on this number was taken as the average crystal grain size D. Then, the standard deviation σ in the lognormal distribution was calculated from the crystal grain size distribution.

2.2 Aggregation The area ratio of crystal grains whose angle θ between the thickness direction (ND) of the titanium alloy plate and the [0001] direction (c-axis) of the α phase is 40 ° or less was calculated by the following method. ..
The cross section of the titanium alloy plate is chemically polished and crystal orientation analysis is performed using EBSD. A region of 2 mm × 2 mm was measured in 10 fields of view in steps 2 μm for each of the lower surface of the titanium alloy plate and the central portion of the plate thickness. For the data, measurement point data in which the angle between the ND and the c-axis is 40 ° or less was extracted using OIM Analysis software manufactured by TSL Solutions.

The observation surface of the titanium sample according to each of the invention examples and the comparative examples was chemically polished, and the crystal orientation was analyzed using the electron backscatter diffraction method to obtain a (0001) pole figure. More specifically, a 2 mm × 2 mm region was scanned at intervals of 2 μm, and (0001) pole figure was drawn using OIM Analysis software manufactured by TSL Solutions. At this time, the position with the highest contour line was defined as the peak position of the degree of integration, and the value with the highest degree of integration among the peak positions was defined as the maximum degree of integration. The maximum degree of integration was calculated using the Texture analysis of the pole figure using the spherical harmonic method (expansion index = 16, Gauss half width = 5 °).

2.3 Al segregation The presence or absence of Al segregation (Al uniformity) was confirmed as follows. By EPMA, the beam diameter is set to 500 μm and the step size is set to 500 μm, which is the same as the beam diameter. went. Then, in order to convert the composition analysis result into the alloy element concentration, JIS Class 1 industrial pure titanium and the target titanium alloy plate were analyzed, and a calibration curve obtained by linear approximation from the result was used. Then, the area ratio of the region where the concentration of Al is ([Al%] −0.2) mass% or more ([Al%] +0.2) mass% or less was determined.

2.4 Twins The cross section of the titanium alloy plate according to each invention example and comparative example in the thickness direction was chemically polished, and the crystal orientation was analyzed using the electron backscatter diffraction method. Specifically, a region of 2 mm × 2 mm was scanned at a position of 1/4 of the plate thickness from the surface of the titanium alloy plate of the sample at intervals of 2 μm, and an inverted pole figure (IPF) was created. At that time, the theoretical values of the rotation axis and crystal orientation difference (rotation angle) of (10-12) twins, (10-11) twins, (11-21) twins, and (11-22) twins that are generated. The area within 2 ° from the twin was regarded as the twin interface. Then, the grain boundary having a crystal orientation difference (angle of rotation) of 2 ° or more was defined as the total grain boundary length, and the ratio of the twin grain boundary length to the total crystal grain boundary length was calculated.

2.5 Area ratio of α phase The cross section of the titanium alloy plate according to each invention example and comparative example in the thickness direction is mirror-polished, and β in the same cross section is formed by SEM / EPMA at a position 1/4 of the plate thickness from the surface. The concentration distribution of the phase stabilizing element was measured, and the portion where the β phase stabilizing element was not concentrated was calculated as the area ratio of the α phase.

2.6 Surface hardness Regarding the surface hardness of the titanium alloy plate according to each invention example and comparative example, after polishing the surface of the titanium alloy plate until it becomes a mirror surface, a Vickers hardness tester is used in accordance with JIS Z 2244: 2009. 3 to 5 points were measured under a load of 1 kg, and the obtained values were averaged to obtain the surface hardness.

2.7 Macro pattern For the macro pattern, the surface of the titanium alloy plate according to each invention example and comparative example of 50 × 100 mm size of about 5 to 10 sheets is polished with # 800 emery paper, and 10% nitric acid and hydrofluoric acid are used. Observation was performed by corroding the surface with a 5% solution. Next, a streak-like pattern having a length of 3 mm or more was used as a macro pattern, and evaluation was performed as follows according to the average generation rate.

A: Occurrence rate is 1.0 pieces / sheet or less (very good, 1.0 pieces or less in 50 x 100 mm)
B: Occurrence rate is more than 1.0 pieces / piece and less than 5.0 pieces / piece (good, more than 1.0 pieces and less than 5.0 pieces in 50 x 100 mm)
C: Occurrence rate is more than 5.0 pieces / sheet and less than 10.0 pieces / sheet (slightly good, more than 5.0 pieces and less than 10.0 pieces in 50 x 100 mm)
D: Occurrence rate exceeds 10.0 pieces / sheet (failure, more than 10.0 pieces in 50 x 100 mm)
The obtained analysis results and evaluation results are shown in Tables 5 and 6.

2.8 Polishability The polishing was performed with # 800 emery paper for observing the macro pattern described above, with the polishing time set to 1 minute. If the surface skin is removed in 1 minute of polishing time, it is judged that the productivity of drum production is maintained, and the polishing property is good (OK). If the surface skin is not removed in 1 minute, the productivity of drum production is determined. It was judged to be unfavorable (NG) because it was judged that the productivity would be reduced.

2.9 Burn-fitting property The shrink-fitting property was evaluated as follows. The shrink fit is affected by Young's modulus and shape ratio (for example, in the case of a pipe plate, the ratio of the outer diameter of the inner pipe to the inner diameter of the outer pipe). In particular, in order to obtain the stress required for fixing titanium, the larger the Young's modulus of titanium, the smaller the amount of deformation can be achieved, so that the heating temperature can be lowered and the workability is improved. Therefore, when the Young's modulus is 135 GPa or more, the shrink fit is excellent.

The obtained analysis results and evaluation results are shown in Tables 5 and 6. The "area ratio (%) of crystal grains having an angle θ of 0 ° or more and 40 ° or less" shown in Tables 5 and 6 is a crystal in which the angle formed by the c-axis of the α phase with respect to the plate thickness direction is 0 ° or more and 40 ° or less. The area ratio of grains. Further, the “Al uniformity (%)” shown in Table 2 is the area of the region where the concentration of Al is ([Al%] −0.2) mass% or more ([Al%] +0.2) mass% or less. The rate. Further, "RT" in the "cold rolling process" shown in Table 2 means room temperature.

As shown in Tables 5 and 6, macro patterns were suppressed in the titanium alloy plates according to Invention Examples 1 to 16 and Invention Examples 101 to 115. On the other hand, many macro patterns were generated in the titanium alloy plates according to Comparative Examples 1 to 5.
Further, in Invention Examples 1 to 16 having a low Al content, the occurrence of macro patterns was further suppressed as compared with Invention Examples 101 to 115 having a high Al content. On the other hand, in Invention Examples 101 to 115 having a high Al content, Young's modulus was high and the shrinkage fit was excellent.

<Example 2>
Assuming application to a copper foil manufacturing drum, a titanium alloy plate obtained by the same method as the invention example of Example 1 shown in Table 7 is used as a base material, processed into a cylindrical shape having a diameter of 1 m, and then butt-welded. The portions (two adjacent ends) were welded using the titanium wire for welding shown in Table 7. For welding, the pre-filling thickness was set to 25% or less of the plate thickness of the base metal. Then, after the pre-filling, only the pre-filled portion was reduced to the base metal thickness at a temperature of 200 ° C. or lower. Finally, the welded portion was heat-treated at 600 to 800 ° C. for 20 to 90 minutes to obtain a welded sample of the titanium wire for welding according to each invention example and each comparative example.

The crystal particle size in the metal structure of the obtained welded portion was measured according to JIS G 0551: 2013 according to a comparative method, and obtained as a particle size number (GSN).
Further, the concentration distribution of Fe or β phase stabilizing element is measured with respect to the metal structure of the welded portion using SEM / EPMA, and the concentration of Fe or the total concentration of β phase stabilizing element is the average concentration in the measurement range. The point (concentrated part) higher than 1 mass% was defined as the β phase, and the area ratio was calculated. Assuming that the area fraction and the volume fraction are equal, the obtained area fraction is the volume fraction of the β phase, and the area fraction of the portion where the β phase stabilizing element is not concentrated (other than the concentrated portion) is the volume fraction of the α phase. The volume fraction of the phase was determined.
Further, the Vickers hardness (Hv) of the welded portion and the base metal in the welded samples according to each of the obtained invention examples and comparative examples was measured at 3 to 5 points under a load of 1 kg, and calculated from the average value. Using a contact-type roughness meter, the step (μm) at the boundary between the welded portion and the base metal portion was measured at λc: 0.8 mm, λs: 2.5 μm, and rtip: 2 μm according to JISB0633: 2001.
Regarding the macro pattern of the welded part in each of the obtained welded samples, the surface of each titanium alloy plate having a size of 50 × 100 mm of about 5 to 10 sheets was polished with a # 800 buff, and a solution of 10% nitric acid and 5% hydrofluoric acid was prepared. The surface was observed after corrosion using. Next, a streak-like pattern generated with a length of 3 mm or more was made into a macro pattern, and the evaluation was performed as follows according to the average of the generation rate.

A: Occurrence rate is 1.0 pieces / sheet or less (very good, 1.0 pieces or less in 50 x 100 mm)
B: Occurrence rate is more than 1.0 pieces / piece and less than 5.0 pieces / piece (good, more than 1.0 pieces and less than 5.0 pieces in 50 x 100 mm)
C: Occurrence rate is more than 5.0 pieces / sheet and less than 10.0 pieces / sheet (slightly good, more than 5.0 pieces and less than 10.0 pieces in 50 x 100 mm)
D: Occurrence rate exceeds 10.0 pieces / sheet (failure, more than 10.0 pieces in 50 x 100 mm)
Further, when a step of 5 μm or more was generated at the boundary between the welded portion and the base metal portion, it was evaluated by D in the macro pattern column.

Further, 10 points each of the convex portion and the concave portion in an arbitrary 50 cm section in the weld bead obtained by welding are measured with a depth gauge, and the average height of the upper three points of the convex portion is h and the average height of the lower three points of the concave portion is measured. When the average height of D and 20 measurement points is A, the cases where the values of (h-A) / A and (AD) / A are all 0.3 or less are OK, 0.1 or less. The case of is Ex.
The results are shown in Table 8.

As shown in Table 8, in Invention Examples 201 to 205, the generation of macro patterns in the welded portion was suppressed. On the other hand, in Comparative Examples 201 and 202, many macro patterns of the welded portion were generated.

According to the present invention, it is possible to provide a titanium alloy plate capable of suppressing the generation of macro patterns when used as a drum for producing copper foil, and a copper foil production drum manufactured using the titanium alloy plate. It becomes.

1 Copper foil manufacturing equipment 2 Electrolytic cell 10 Electrolytic cell 30 Electrode plate 40 Winding part 50 Guide roll 60 Winding roll A Copper foil 20 Copper foil manufacturing drum 21 Inner drum 22 Titanium alloy plate 23 Welded part

The gist of the present invention completed based on the above findings is as follows.
[1] The titanium alloy plate according to one aspect of the present invention has Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0 in mass%. 1 type or 2 types or more composed of a group consisting of% or less: 0.2% or more and 7.0% or less in total (however, only one type with Al: 0.4% or more and 1.8% or less) ) , N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, O: 0.700% or less, and Fe: 0.500% or less. The balance has a chemical composition containing Ti and impurities, the average crystal grain size is 40 μm or less, the standard deviation of the grain size distribution based on the logarithm of the crystal grain size in the unit μm is 0.80 or less, and the crystal. The structure includes an α phase having a hexagonal close-packed structure, and the area ratio of crystal grains having an angle formed by the α phase in the [0001] direction with respect to the plate thickness direction is 0 ° or more and 40 ° or less is 70% or more.
[2] The titanium alloy plate according to the above [1] has a development index of the pole diagram using the spherical harmonic method of the electron backscatter diffraction method in the (0001) pole diagram from the normal direction of the plate surface. 16. The peak of the degree of integration calculated by the Function analysis when the Gaussian full width at half maximum is 5 ° exists within 30 ° from the normal direction of the plate surface, and the maximum degree of integration is 4.0 or more. It may have an aggregate structure that is.
[3] In the titanium alloy plate according to the above [1] or [2], when the average crystal grain size is D in the unit μm, the standard deviation of the particle size distribution is (0.35 × lnD−). It may be 0.42) or less.
[4] The titanium alloy plate according to any one of [1] to [3] above has a total grain boundary of the plate thickness cross section at a position of 1/4 of the plate thickness from the surface when the plate thickness direction cross section is observed. The ratio of the twin grain boundary length to the length may be 5.0% or less.
[ 5 ] The titanium alloy plate according to any one of [1] to [4] above contains Al: more than 1.8% and 7.0% or less in the chemical composition, and has a Vickers hardness of 350 Hv or less. There may be.
[ 6 ] The titanium alloy plate according to the above [5 ] has an Al content of [Al%], a Zr content of [Zr%], a Sn content of [Sn%], and an O content in mass%. When is [O%], the Al equivalent Aleq represented by the following formula (1) may be 7.0 or less.
Alex = [Al%] + [Zr%] / 6 + [Sn%] / 3 + 10 × [O%] Equation (1)
[ 7 ] The titanium alloy plate according to [5 ] or [ 6 ] above is analyzed using an electron probe microanalyzer on a surface 20 mm × 20 mm or more perpendicular to the plate thickness direction at a position 1/4 of the plate thickness from the surface. When the region was analyzed for composition, the average content of Al was [Al%], and the concentration of Al was ([Al%] -0.2) mass% or more ([Al%] +0) with respect to the area of the analysis region. .2) The area ratio of the region of mass% or less may be 90% or more.
[ 8 ] The titanium alloy plate according to any one of [1] to [ 7 ] above may contain 98.0% by volume or more of the α phase.
[ 9 ] The titanium alloy plate according to any one of [1] to [ 8 ] above may be a titanium alloy plate for a copper foil manufacturing drum.
[ 10 ] The copper foil manufacturing drum according to another aspect of the present invention includes a cylindrical inner drum and titanium according to any one of [1] to [9], which is adhered to the outer peripheral surface of the inner drum. It has an alloy plate and a welded portion provided at a butt portion of the titanium alloy plate, and the metal structure of the welded portion has an α phase of 98.0% or more in terms of volume ratio, and JIS G 0551 : A particle size number based on 2013, which is 6 or more and 11 or less.
[ 11 ] In the method for manufacturing a copper foil manufacturing drum according to another aspect of the present invention, two adjacent ends of a titanium alloy plate processed into a cylindrical shape according to any one of [1] to [9] are formed. It has a welding process of welding using a titanium wire for welding, and the titanium wire for welding is one or more selected from the group consisting of Sn, Zr and Al in mass%: 0.2% or more in total 6 0.0% or less, O: 0.01% or more and 0.70% or less, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, and Fe: 0.500% or less , And the balance has a chemical composition containing Ti and impurities.
[ 12 ] The method for manufacturing a copper foil manufacturing drum according to the above [11 ] is one type in which at least a part of the O is selected from the group consisting of Ti, Sn, Zr and Al in the titanium wire rod for welding. It may exist as an oxide of the above elements.

Claims (13)

By mass%
Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0% or less. 0.2% or more and 7.0% or less,
N: 0.100% or less,
C: 0.080% or less,
H: 0.015% or less,
O: 0.700% or less, and
Fe: 0.500% or less,
The balance has a chemical composition containing Ti and impurities,
The average crystal grain size is 40 μm or less,
The standard deviation of the particle size distribution based on the logarithm of the crystal particle size in the unit μm is 0.80 or less.
The crystal structure contains an α phase, which is a hexagonal close-packed structure.
The area ratio of the crystal grains having an angle formed by the α phase in the [0001] direction with respect to the plate thickness direction of 0 ° or more and 40 ° or less is 70% or more.
Titanium alloy plate. In the (0001) pole map from the normal direction of the plate surface, the texture analysis when the expansion index of the pole map using the spherical harmonics method of the electron backscatter diffraction method is 16 and the Gaussian half width is 5 °. The peak of the calculated degree of integration exists within 30 ° from the normal direction of the plate surface, and has a texture having a maximum degree of integration of 4.0 or more.
The titanium alloy plate according to claim 1. The titanium alloy plate according to claim 1 or 2, wherein the standard deviation of the particle size distribution is (0.35 × lnD −0.42) or less when the average crystal particle size is D in units of μm. .. When observing the cross section in the plate thickness direction, the ratio of the twin grain boundary length to the total grain boundary length of the plate thickness cross section at the position of 1/4 of the plate thickness from the surface is 5.0% or less. Item 2. The titanium alloy plate according to any one of Items 1 to 3. In the chemical composition
Sn: 0.2% or more and 2.0% or less,
1 type or 2 types or more composed of a group consisting of Zr: 0.2% or more and 5.0% or less, and Al: 0.2% or more and 3.0% or less, 0.2% or more in total 5 Contains less than 0.0%,
The titanium alloy plate according to any one of claims 1 to 4. In the chemical composition
Al: Containing more than 1.8% and less than 7.0%,
Vickers hardness is 350 Hv or less,
The titanium alloy plate according to any one of claims 1 to 4. When the Al content is [Al%], the Zr content is [Zr%], the Sn content is [Sn%], and the O content is [O%] in mass%, the following formula (1), The Al equivalent Aleq represented by is 7.0 or less.
The titanium alloy plate according to claim 6.
Alex = [Al%] + [Zr%] / 6 + [Sn%] / 3 + 10 × [O%] Equation (1) When the composition analysis of the analysis area of the surface 20 mm × 20 mm or more perpendicular to the plate thickness direction at the position of 1/4 of the plate thickness from the surface using an electron probe microanalyzer, the average Al content is defined as [Al%]. The area ratio of the region where the concentration of Al is ([Al%] −0.2) mass% or more ([Al%] +0.2) mass% or less with respect to the area of the analysis region is 90% or more. The titanium alloy plate according to claim 6 or 7. The titanium alloy plate according to any one of claims 1 to 8, which contains 98.0% by volume or more of the α phase. The titanium alloy plate according to any one of claims 1 to 9, which is a titanium alloy plate for a copper foil manufacturing drum. Cylindrical inner drum and
The titanium alloy plate according to any one of claims 1 to 10, which is adhered to the outer peripheral surface of the inner drum.
The welded portion provided at the butt portion of the titanium alloy plate and the welded portion
Have,
The metal structure of the welded portion has an α phase of 98.0% or more in volume fraction, and has a particle size number of 6 or more and 11 or less in accordance with JIS G 0551: 2013.
Copper foil manufacturing drum. It has a welding process in which two adjacent ends of a titanium alloy plate processed into a cylindrical shape are welded using a titanium wire for welding.
The titanium wire for welding is based on mass%.
One or more selected from the group consisting of Sn, Zr and Al: 0.2% or more and 6.0% or less in total,
O: 0.01% or more and 0.70% or less,
N: 0.100% or less,
C: 0.080% or less,
H: 0.015% or less, and Fe: 0.500% or less, including
The balance has a chemical composition containing Ti and impurities,
Copper foil manufacturing method of manufacturing drums. In the titanium wire for welding, at least a part of O is present as an oxide of one or more elements selected from the group consisting of Ti, Sn, Zr and Al.
The method for manufacturing a copper foil manufacturing drum according to claim 12.

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