JP2007247006A - Aluminum based alloy preform, aluminum based alloy dense body, method for producing them and sputtering target - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique, where the variation in the density of an aluminum based alloy preform by a spray forming process is reduced, and the preform can be produced in a high yield. <P>SOLUTION: In the aluminum based alloy preform, the average of relative density is 50 to 65%, and the difference between the part showing the maximum value of the relative density and the part showing the minimum value of the relative density is ≤30%. The method for producing the preform includes: a stage where an aluminum based alloy is melted within the range of (liquidus temperature+100°C) to (liquidus temperature+400°C), so as to obtain the molten metal of the aluminum based alloy; a stage where the molten metal of the aluminum based alloy is subjected to gas atomizing under the conditions in which the gas/metal ratio is ≥4 Nm<SP>3</SP>/kg, and, provided that the angle made by the central axis of the confronted gas atomizing nozzle is defined as 2α, α satisfies 1 to 10°, so as to be atomized; and a stage where the atomized aluminum based alloy is deposited on a collector under the conditions in which spray distance is 700 to 1,200 mm and the collector angle is 20 to 45°, so as to obtain the preform. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an aluminum-base alloy preform and an aluminum-base alloy dense body obtained by using a spray forming method, a production method thereof, and a sputtering target obtained by using these. The aluminum-based alloy dense body of the present invention is suitable as a material for, for example, wiring films for liquid crystal displays, reflective electrode films, reflective films, light-shielding films, etc .; reflective films for optical disks and magneto-optical disks, and heat diffusion films. Used.

  Aluminum-based alloys are widely used in fields such as liquid crystal displays and optical disks because of their low specific resistance and ease of processing. In particular, aluminum-based alloy thin films formed by sputtering can dissolve alloy elements such as Nd that cannot be dissolved in equilibrium and show high performance as thin films. Is underway.

  The main characteristics required for sputtering target materials include composition uniformity, refinement and uniformity of structure (mainly intermetallic compounds of aluminum and alloy components), purity (reduction of oxygen and nitrogen content, etc.) Is mentioned. In particular, in the target material for liquid crystal display, the refinement and uniformity of the structure are very important. If there is a non-uniform part of the structure, fine molten particles (splash) are generated from the non-uniform part during sputtering. However, since the phenomenon of adhering to the substrate is noticeable, the yield of liquid crystal display manufacturing is reduced. Moreover, when the oxygen concentration or nitrogen concentration in the target material increases, the electrical resistivity of the aluminum-based alloy thin film increases.

  Of these, the spray forming method has attracted attention as a technique that can greatly improve the refinement and uniformity of the structure.

  The spray forming method atomizes various molten metals with gas and deposits particles that are rapidly cooled to a semi-molten, semi-solid, or solid phase, and then forms a shaped material (before obtaining the final dense body) (Hereinafter referred to as “preform”). According to this method, there is an advantage that a large preform that is difficult to obtain by a melt casting method, a powder sintering method, or the like can be obtained in a single step.

  As a technique for manufacturing an aluminum-based alloy preform using the spray forming method, the present applicant has disclosed the techniques of Patent Documents 1 to 3, for example.

Patent Document 1 is a technique in which the spray forming method is first applied to the production of a refractory metal-containing aluminum-based alloy preform. The aim here is to increase the density of the preform itself (the densification means is not an essential process), and mainly the temperature during gas atomization and the gas / metal ratio to 1-5 Nm ³ / kg. By controlling, generation of huge crystallized substances (mainly intermetallic compounds) is suppressed.

  Patent Documents 2 and 3 are different from Patent Document 1 and relate to a technique in which a dense body is formed by applying densification means such as forging and rolling to a preform having a predetermined density.

Patent Document 2 describes a method of controlling the gas / metal ratio during gas atomization to 5 Nm ³ / kg or more and reducing the size (maximum length) of the crystallized product in order to suppress splash generated during sputtering. ing.

Patent Document 3 relates to a technique for increasing the high temperature strength of an aluminum-based alloy dense body. Here, in order to increase the high temperature strength of the dense body, the gas / metal ratio is set to 5 Nm ³ / kg based on the knowledge that the intermetallic compound should be refined and the volume fraction of the intermetallic compound should be increased. A method is described in which after performing the above control to obtain a preform, a predetermined hot isostatic pressing is performed to crush the pores of the preform.

In addition to the above, for example, in Patent Document 4, a rough extrusion is performed by adopting an equal cross-sectional area side extrusion method that has been used exclusively as a processing means for superplastic material when pressing and extruding an aluminum-based alloy preform. A method for destroying intermetallic compounds and eliminating uneven distribution of particles is described. Here, it is also described that the preform is produced by keeping the molten aluminum-based alloy in the range of + 50 ° C. to + 150 ° C. of the liquidus temperature.
JP-A-9-248665 JP 11-315373 A JP 2005-82855 A JP 2000-225412 A

  In recent years, the demand for an aluminum-based alloy preform by a spray forming method and a dense body using the same has been increasing. However, a technique for manufacturing a preform with a high yield and a technique for stably manufacturing a dense body having a fine structure with a high yield are not provided.

  The present invention has been made paying attention to such circumstances, and its purpose is to control the density and dispersion of the aluminum-based alloy preform by the spray forming method, and the yield of the preform and the dense body. It is to provide a technology that improves the quality.

  Another object of the present invention is to provide a technique for stably producing an aluminum-based alloy dense body having a fine structure with a high yield using the above-described preform.

  The aluminum-based alloy preform of the present invention that has solved the above problems is an aluminum-based alloy preform obtained by a spray forming method, having an average relative density of 50 to 65% and a maximum relative density. The gist is that the difference between the portion showing the value and the portion showing the minimum value of the relative density is 30% or less.

  In a preferred embodiment, the aluminum-based alloy contains Nd.

  The aluminum-based alloy dense body of the present invention can be obtained using the above-mentioned aluminum-based alloy preform.

  The sputtering target of this invention is obtained using said aluminum base alloy dense body.

An aluminum-based alloy preform manufacturing method according to the present invention that has solved the above-mentioned problems is a method of manufacturing an aluminum-based alloy preform by a spray forming method, wherein the aluminum-based alloy is (liquidus temperature + 100 ° C.) A first step of melting within a range of (liquid phase temperature + 400 ° C.) to obtain a molten aluminum-based alloy, and a molten metal of the aluminum-based alloy having a gas / metal ratio of 4 Nm ³ / kg or more, and When the angle formed by the opposing gas atomizing nozzle central axis is 2α, the second step of gas atomizing and refining α under the condition of 1 to 10 ° and the refined aluminum-based alloy have a spray distance of 700. A third step of depositing on the collector under the conditions of -1200 mm and a collector angle of 20-45 ° to obtain a preform. Contains.

A method for producing an aluminum-based alloy dense body according to the present invention that has solved the above-described problems is a method for producing an aluminum-based alloy dense body by a spray forming method, wherein the aluminum-based alloy is (liquidus temperature + 100 ° C.). The first step of melting within a range of (liquid phase temperature + 400 ° C.) to obtain a molten aluminum based alloy and the molten aluminum based alloy have a gas metal ratio of 4 Nm ³ / kg or more and When the angle formed by the central axis of the gas atomizing nozzle is 2α, α is gas atomized under the condition of 1 to 10 °, and the second step of refining and the refined aluminum-based alloy have a spray distance of 700 to A third step of obtaining a preform by depositing on the collector under the conditions of 1200 mm and a collector angle of 20 to 45 °; And a fourth step of densifying the alloy preform by densification means.

  In a preferred embodiment, the fourth step includes a step of performing hot isostatic pressing at a temperature of 400 to 600 ° C. under a pressure of 80 MPa or more.

  According to the present invention, since the density of aluminum-based alloy preform by the spray forming method and its variation are controlled, the yield in the spray forming step [weight of preform / (weight of molten alloy−weight of remaining metal)] is Increased to 85% or more.

  The dense body obtained using the above aluminum-based alloy preform has a maximum structure grain size of 5 μm or less, and the yield in the densification step (weight of the dense body / weight of the preform) is 85%. More than that.

  In order to provide a method for manufacturing a preform with a high yield by controlling the density and dispersion of the aluminum-based alloy preform by the spray forming method, the present inventor has re-examined each process of the preform manufacturing. . As a result, if the melting temperature of the alloy at the time of molten metal preparation, the gas / metal ratio and gas atomization outlet angle during gas atomization, and the spray distance and collector angle during collector deposition are all properly controlled, the intended purpose is achieved. I found out. Furthermore, it has been found that when a dense body is produced by applying a predetermined densification means to the preform thus obtained, a dense body having a fine structure can be obtained with a high yield, and the present invention has been completed.

  As in the present invention, what has been precisely set an appropriate condition for obtaining a desired preform throughout all of the melt preparation process, gas atomization process, and collector deposition process of an aluminum-based alloy has been disclosed so far. Absent. For example, the above-mentioned patent documents include control of alloy melting temperature (Patent Document 4), control of gas / metal ratio during gas atomization (Patent Documents 2 to 3), and control of densification means from a preform to a dense body. As in (Patent Document 3), only a method for controlling only a part of the entire process is disclosed.

  The present invention is positioned as a culmination technology as a result of the practical application of the applicant of this application after 1996 when the above-mentioned Patent Document 1 was filed.

(Aluminum-based alloy preform)
First, the aluminum-based alloy preform of the present invention will be described.

  The preform of the present invention has an average value of relative density (average relative density) of 50 to 65%, and a difference between a portion showing the maximum value of relative density and a portion showing the minimum value of relative density (variation of relative density). ) Is 30% or less.

  First, the average relative density of the preform is 50 to 65%.

  Here, the main reason why the upper limit of the average relative density is defined as 65% is that, in the present invention, it is assumed that the preform is subjected to densification means to obtain a high-density dense body. Further, as shown in the examples described later, when a preform having a large average relative density is used, the yield of the preform is lowered. Furthermore, a coarse structure (details of the structure will be described later) is generated in the dense body obtained from such a preform.

  On the other hand, when the average relative density of the preform is less than 50%, there is a problem in that the strength of the preform is lowered and chipping occurs during handling, as shown in Examples described later. Further, when a densifying means is applied to a preform having a low average relative density, deformation of the dense body increases and yield decreases.

  Considering these points, the average relative density of the preform is preferably 55% or more and 60% or less.

  Further, the variation in the relative density of the preform is 30% or less.

  As shown in the examples described later, when the variation in relative density exceeds 30%, the yield of the preform tends to decrease. Further, deformation and defects occur in the dense body obtained from such a preform. The smaller the variation in the relative density of the preform, the better. For example, it is preferably 25% or less, and more preferably 20% or less.

  Here, the relative density inside the preform was determined as follows.

  First, as shown in FIG. 1A, a cylindrical sample having a diameter of 365 mm and a height of 600 mm is prepared. For each of the upper part (T in the figure), the center part (M in the figure), and the bottom part (B in the figure) of this sample, the relative density measurement sample shown in FIG. The relative density is calculated from the weight. A total of 30 relative density measurement samples were collected from each of the top, center, and bottom.

  The average value of the relative densities of the samples thus obtained was defined as “average relative density”, and the difference between the maximum value and the minimum value of relative density was defined as “relative density variation”.

(Preform manufacturing method)
The method for producing the preform includes a first step of melting the aluminum base alloy within a range of (liquid phase temperature + 100 ° C.) to (liquid phase temperature + 400 ° C.) to obtain a molten aluminum base alloy; When the molten metal of the aluminum base alloy has a gas / metal ratio of 4 Nm ³ / kg or more expressed by the ratio of gas outflow / melt outflow, and the angle formed by the opposing gas atomizing nozzle central axis is 2α, α Is deposited on the collector under the conditions of a spray distance of 700 to 1200 mm and a collector angle of 20 to 45 °. And a third step of obtaining a preform.

  Hereafter, each process is demonstrated in detail, referring FIG. 2 and FIG.

  FIG. 2 is a sectional view partially showing an example of an apparatus used for manufacturing the preform of the present invention. 3 is an enlarged view of a main part X in FIG.

  The apparatus shown in FIG. 2 includes an induction melting furnace 1 for melting an aluminum-based alloy, gas atomizers 3a and 3b installed below the induction melting furnace 1, and a collector 5 for depositing a preform. ing. The induction melting furnace 1 has a nozzle 6 for dropping a molten metal 2 of an aluminum base alloy. The gas atomizers 3a and 3b have bobbin gas holes 4a and 4b for atomizing the gas, respectively. The collector 5 has driving means (not shown) such as a stepping motor.

(First step)
First, an aluminum base alloy is prepared.

  The aluminum-based alloy used in the present invention includes both aluminum and aluminum alloys. As the alloy component, those used for sputtering target materials are preferable, for example, rare earth elements such as Nd and Y, transition metals (refractory metals) such as Ta, Ti, Zr, V, Nd, Cr, W, and Mo. Is mentioned. Specifically, for example, Al-Ni-La alloy, Al-Ni-Nd alloy, Al-Hf-Y alloy, Al-Fe-Si alloy, Al-Cu alloy, Al-Ta alloy, Al-Ti alloy, Al-Nd-Ta alloy, Al-Nd alloy, etc. are mentioned.

  The rare earth elements contained in the aluminum are contained in one or more kinds in the aluminum, and are preferably contained in the range of about 0.1 to 3.0 atomic% in total. The above transition metals are contained in one or more kinds in aluminum, and are preferably contained in a range of about 0.1 to 6 atomic% in total.

  After the aluminum-based alloy is charged into the induction melting furnace 1, it is preferably melted in a range of + 100 ° C. to + 400 ° C. with respect to the liquid phase temperature of the aluminum-based alloy in an inert gas atmosphere. Obtain molten metal 2.

  The melting temperature of the alloy is one of the factors that greatly affect the temperature and size of the fine particles (droplets) obtained by gas atomization, and ultimately affects the refinement of the dense structure (see below). See examples).

  When the melting temperature of the alloy is lower than (liquid phase temperature + 100 ° C.), the molten metal 2 is solidified when passing through the nozzle, and the nozzle may be blocked. On the other hand, when the melting temperature of the alloy exceeds (liquidus temperature + 400 ° C.), the temperature of the droplets increases, the average relative density of the preform increases, and the yield decreases. Moreover, the structure of the dense body obtained from such a preform becomes coarse and the yield decreases. In addition to the above, considering the oxidation of the molten metal, the life of the refractory, energy loss, etc., the melting temperature of the alloy should be in the range of (liquid phase temperature + 150 ° C) to (liquid phase temperature + 300 ° C). Is preferred.

  Note that the aluminum-based alloy is preferably dissolved in an inert gas atmosphere or a nitrogen gas atmosphere as described above, thereby suppressing oxidation of the alloy. Examples of the inert gas include argon gas.

(Second step)
Next, the molten alloy 2 obtained as described above is dropped through a nozzle 6 in a chamber (not shown) in an inert gas atmosphere. In the chamber, a high-pressure inert gas jet is blown to the molten alloy 2 from the gas holes 4a and 4b of the bobbins installed in the gas atomizers 3a and 3b, whereby the molten alloy is refined.

  The gas atomization is preferably performed using an inert gas or a nitrogen gas as described above, thereby suppressing the oxidation of the molten metal. Examples of the inert gas include argon gas.

Here, the gas / metal ratio is set to 4 Nm ³ / kg or more. The gas / metal ratio is represented by the ratio of gas outflow / melt outflow.

  In this specification, the gas outflow amount means the total amount (finally used amount) of gas flowing out from the gas holes 4a and 4b of the bobbin in order to gas atomize the molten aluminum-based alloy. In the specification of the present application, the amount of molten metal flowing out means the total amount of molten metal flowing out from the molten metal outlet (nozzle 6) of a container (induction melting furnace 1) containing molten aluminum.

The gas / metal ratio, like the melting temperature of the alloy, is one of the factors affecting the droplet size, and greatly affects the cooling rate of the droplet. When the gas / metal ratio is controlled to 4 Nm ³ / kg or more, the change in droplet size decreases and approaches a constant value. On the other hand, when the gas / metal ratio is less than 4 Nm ³ / kg, the change in the droplet size increases and the yield of the preform decreases (see the examples described later).

If the above point of view, the gas / metal ratio may larger, for example, is preferably ^{5 Nm} 3 / kg or more, more preferably ^{7 Nm} 3 / kg or more. The upper limit is not particularly limited, but in consideration of the stability and cost of the droplet flow during gas atomization, it is preferably 15 Nm ³ / kg or less, and more preferably 10 Nm ³ / kg.

  Furthermore, when the angle formed by the opposing gas atomizing nozzle central axes 6a and 6b is 2α, α is controlled within a range of 1 to 10 °. The angle 2α formed by the opposing gas atomizing nozzle central axes 6a and 6b is the inclination of each of the gas atomizers 4a and 4b with respect to a line (corresponding to the spray axis A) when the molten metal 2 falls down as shown in FIG. It means the total angle of α. Hereinafter, this α is referred to as “gas atomizing outlet angle α”.

  The gas atomization outlet angle α is one of the factors affecting the size of the droplets, like the melting temperature of the alloy and the gas / metal ratio described above. The gas atomization outlet angle α further affects the spread of the droplets, and affects the yield of the preform, the structure of the dense body, and the yield (see Examples described later).

  When the gas atomization outlet angle α exceeds 10 °, the liquid droplets tend to spread, and the dispersion of the relative density increases and the yield of the preform decreases. Furthermore, the yield of dense bodies is also reduced. On the other hand, when the gas atomization outlet angle α is less than 1 °, the atomization effect is reduced, so that the droplet size increases and the preform relative density increases, the yield of the preform decreases, and the structure of the dense body becomes coarse. Invite Considering these viewpoints, the gas atomization outlet angle α is preferably 3 ° or more and 7 ° or less.

  FIG. 3 shows an example in which one gas hole 4a, 4b of the bobbin is provided for each of the gas atomizers 3a, 3b. However, the present invention is not limited to this. Usually, a plurality of bobbin holes are provided in accordance with a desired gas amount.

(Third step)
Next, the aluminum-based alloy (droplets) refined as described above is deposited on the collector 5 to obtain a preform.

  Here, the spray distance is controlled within a range of 700 to 1200 mm. The spray distance defines the accumulation position of the droplets, and means a distance L from the tip of the nozzle 6 to the center of the collector 5 as shown in FIG. As will be described later, since the collector 5 is inclined at the collector angle β, the spray distance L strictly means the distance between the tip of the nozzle 6 and the point A1 where the center of the collector 5 is in contact with the spray axis A. is doing. Here, for the convenience of explanation, the spray axis A defines the direction in which a droplet of an aluminum-based alloy falls directly below.

  The reason why the spray distance L is defined as described above is that the cooling rate of the liquid droplets varies depending on the position where the liquid droplets are collected, and the average relative density of the preform and the structure of the dense body are changed (described later). See examples). Further, the yield of the preform and the dense body also changes depending on the spray distance L.

  When the splay distance is less than 700 mm, the preform yield decreases because the preform in a semi-molten state or a semi-solid state is deposited on the collector 5 at a high droplet temperature. Furthermore, the dense structure is also coarsened. On the other hand, when the spray distance L exceeds 1200 mm, the ratio of depositing on the collector 5 in the solid phase rather than the semi-molten or semi-solid state increases, the preform density decreases, and the yield decreases. Furthermore, the yield of dense bodies is also reduced. The spray distance L is preferably in the range of 950 to 1150 mm.

  Although the spray distance L changes during the deposition of the preform, in the present invention, the collector 5 is adjusted so that the spray distance L is always within the above range. Specifically, it is preferable to gradually lower the collector 5 by rotating a driving means (not shown) such as a stepping motor installed in the collector 5.

  Further, the collector angle β is controlled within a range of 20 to 45 °.

  The collector angle β means the inclination of the collector 5 with respect to the spray axis A as shown in FIG. It has been found that the collector angle β also affects the density and yield of the preform, and further the yield of the dense body (see examples described later).

  When the collector angle β is less than 20 °, the dispersion of the relative density of the preform increases, and the yield of the dense body decreases. On the other hand, when the collector angle β exceeds 45 °, the dispersion of the relative density of the preform increases, and the yield of the dense body decreases. The collector angle β is preferably 25 ° or more and 40 ° or less.

  The average relative density and the variation in relative density of the preforms thus obtained satisfy the above-mentioned range, and a desired preform can be obtained with a high yield of 85% or more (implementation to be described later) See example).

  The shape of the preform is, for example, a columnar shape or a disk shape.

(Dense body and manufacturing method thereof)
The dense body obtained by using the above preform has a fine structure, and the occurrence of splash is remarkably suppressed.

  Here, “structure” mainly means an intermetallic compound of aluminum and an alloy component, and also includes an alloy component and an oxide thereof. “Fine structure” means that the maximum particle size of the structure is 5 μm or less.

  Here, the maximum particle size of the dense structure was determined as follows.

  First, as shown in FIG. 4A, a cylindrical sample having a diameter of 300 mm and a height of 500 mm is prepared. For each of the upper part (T in the figure), the central part (M in the figure), and the bottom part (B in the figure) of this sample, a total of six places crystallized near the center and the periphery are shown in FIG. ) Is taken and observed at 2000 times using a laser microscope using a blue laser as a light source, and the major axis of the tissue is measured visually or using an image analysis device. Particle size ".

  The dense body of the present invention is obtained by applying a densifying means to the preform (fourth step).

  The densification means means a means for increasing the density of the preform (average relative density of 50 to 65%) (generally, the average relative density of 57% or more). Here, it is preferable to perform a method of pressurizing the preform in a substantially isobaric direction, particularly hot isostatic pressing (HIP) in which the preform is hot-pressed. Specifically, as shown in the examples described later, it is preferable to perform the HIP treatment at a temperature of 400 to 600 ° C. under a pressure of 80 MPa or more, whereby a desired dense body can be obtained with a high yield of 85% or more. Obtainable. This is because when the HIP process is performed under the above conditions, the deformation of the dense body can be minimized, and the weight loss that occurs when the deformed portion is removed by machining can be minimized.

  When the HIP temperature is less than 400 ° C. and the HIP pressure is less than 80 MPa, the density of the dense body cannot be sufficiently increased, and defects or the like are generated inside. On the other hand, when the HIP temperature exceeds 600 ° C., the dense structure becomes coarse. Preferably, the HIP treatment is performed at a temperature of 500 to 550 ° C. under a pressure of 100 MPa or more. It is preferable that the HIP treatment time is approximately in the range of 1 to 10 hours.

(Sputtering target)
In the present invention, a sputtering target obtained by using the above aluminum-based alloy dense body is also included in the scope of the present invention.

  The manufacturing conditions of the sputtering target are not particularly limited, and a general method can be adopted. For example, the above dense body is forged to obtain a slab, then rolled, and further machined into a predetermined shape to obtain a sputtering target. The rolling includes finish rolling as necessary. The sputtering target thus obtained is used by bonding to a backing plate using In solder, for example.

  According to the present invention, a target having a uniform particle size and dispersed state of metal crystals and intermetallic compounds can be obtained.

  The sputtering target of the present invention is suitably used for, for example, wiring films for liquid crystal displays, reflective electrode films, reflective films, light-shielding films, etc .; reflective films for optical disks and magneto-optical disks, thermal diffusion films, and the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, and is implemented with modifications within a range that can meet the purpose described above and below. These are all included in the technical scope of the present invention.

Example 1 (No. 1-25)
Al-2.0 atomic% Nd (liquid phase temperature: about 650 ° C.) was prepared, and a cylindrical preform was obtained under the conditions shown in Table 1. The size of the preform is approximately φ365 mm and height 600 mm. Nitrogen gas was used for gas atomization.

The preform was subjected to HIP treatment under the conditions shown in Table 1 to obtain a dense body (density 2.87 g / cm ³ ). Specifically, after the preform was sealed in a capsule for HIP, the inside of the capsule was evacuated and evacuated. The capsule was placed in a HIP apparatus, heated and pressurized for 10 hours under the conditions shown in Table 1, and the density of the preform was 100. The capsule was then removed from the HIP device and the capsule was removed. The size after removal is φ300 mm and the height is about 500 mm.

  The average relative density and variation in relative density of the preforms thus obtained were calculated based on the method described above, and the maximum particle size of the dense structure was measured.

Furthermore, the yield of the preform in the spray forming process and the yield of the dense body in the densification process were determined as follows. In this example, the yields of the preform and the dense body were 85% or more, respectively.
Yield (%) in spray forming process
= [(Weight of preform / (weight of molten metal of alloy−weight of remaining hot metal)] × 100
Here, the remaining hot water is the weight of the molten metal remaining at the bottom of the crucible.
Yield in densification process (%)
= (Weight of dense body / weight of preform) × 100
These results are also shown in Table 1.

  No. 2 to 3, 6, 8 to 10, 15 to 17, 20, 22 to 23, and 25 are examples of the present invention in which preforms were produced under the conditions defined in the present invention. Obtained with high yield. When the above-described preform was used and HIP treatment was performed under the preferred conditions of the present invention, a dense body having a fine structure was obtained with a good yield.

  On the other hand, the following comparative example that does not satisfy any of the conditions defined in the present invention has the following problems.

  No. No. 1 is an example in which the gas / metal ratio is small, and the yield of the preform was lowered.

  No. 11 and 12 are examples in which the splay distance is outside the scope of the present invention. No. When the splay distance was shortened as in 11, the average relative density of the preform was increased and the yield was decreased. No. When the splay distance was increased as shown in 12, the average relative density of the preform was reduced, and the yield was reduced. Even if these preforms are used and a predetermined HIP treatment is performed, a desired dense body cannot be obtained. In 11, a coarsened structure was generated. No. In No. 12, chipping occurred during the handling of the preform, and the yield of the dense body decreased.

  No. Examples 13 and 14 are examples in which the melting temperature of the alloy falls outside the scope of the present invention. No. When the melting temperature was increased as in No. 13, the average relative density of the preform was increased and the yield was decreased. The structure of the dense body using this preform was coarsened. On the other hand, no. When the dissolution temperature was lowered as in 14, the nozzle was clogged.

  No. 18 and 19 are examples in which the gas atomization outlet angle is outside the scope of the present invention. No. When the gas atomization outlet angle was increased as shown in FIG. 18, the dispersion of the relative density of the preform increased, and the yields of the preform and the dense body decreased. On the other hand, no. When the gas atomization outlet angle is set to 0 (vertically vertically downward) as in 19, the average relative density of the preform increases, leading to a decrease in the yield of the preform and the coarsening of the dense structure.

  No. 21 and 24 are examples in which the collector angle is outside the scope of the present invention. No. When the collector angle was small as in No. 21, the dispersion of the relative density of the preform was increased, and the yield of the dense body was lowered. On the other hand, no. When the collector angle was large as in 24, the dispersion of the relative density of the preform was increased, and the yields of the preform and the compact were both reduced.

  No. Examples 4 to 5 and 7 are examples in which the temperature and pressure during the HIP treatment are out of the scope of the present invention. No. No. 4 is an example where the pressure is high. 7 is an example where the temperature is low, and in all cases, defects occurred in the dense body. No. When the temperature was increased as in 5, a coarse structure was formed.

FIG. 1 is a diagram for explaining the measurement position of the relative density of the preform. FIG. 2 is a sectional view partially showing an example of an apparatus used for manufacturing the preform of the present invention. 3 is an enlarged view of a main part X in FIG. FIG. 4 is a diagram for explaining a measurement position of a dense tissue.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Induction melting furnace 2 Molten aluminum alloy 3a, 3b Gas atomizer 4a, 4b Bobbin gas hole 5 Collector 6 Nozzle 6a, 6b Gas atomizing nozzle central axis A Spray axis L Spray distance α Gas atomizing outlet angle β Collector angle L Spray distance

Claims (7)

An aluminum-based alloy preform obtained by a spray forming method,
An aluminum-based alloy preform characterized in that the average relative density is 50 to 65%, and the difference between the portion showing the maximum value of the relative density and the portion showing the minimum value of the relative density is 30% or less.   The aluminum-based alloy preform according to claim 1, wherein the aluminum-based alloy contains Nd.   An aluminum-based alloy dense body obtained using the aluminum-based alloy preform according to claim 1.   A sputtering target obtained using the aluminum-based alloy dense body according to claim 3. A method for producing an aluminum-based alloy preform by a spray forming method,
A first step of melting an aluminum base alloy within a range of (liquid phase temperature + 100 ° C.) to (liquid phase temperature + 400 ° C.) to obtain a molten aluminum base alloy;
When the molten metal of the aluminum base alloy has a gas / metal ratio of 4 Nm ³ / kg or more and the angle formed by the opposing gas atomizing nozzle central axis is 2α, α is gas atomized under the condition of 1 to 10 °, and fine A second step of
A third step of depositing the refined aluminum-based alloy on a collector under conditions of a spray distance of 700 to 1200 mm and a collector angle of 20 to 45 ° to obtain a preform;
A process for producing an aluminum-based alloy preform characterized by comprising: A method for producing an aluminum-based alloy dense body by a spray forming method,
A first step of melting an aluminum base alloy within a range of (liquid phase temperature + 100 ° C.) to (liquid phase temperature + 400 ° C.) to obtain a molten aluminum base alloy;
When the molten metal of the aluminum-based alloy has a gas metal ratio of 4 Nm ³ / kg or more and the angle formed by the opposing gas atomizing nozzle central axis is 2α, α is gas atomized under the condition of 1 to 10 °, and refined A second step of:
A third step of depositing the refined aluminum-based alloy on a collector under conditions of a spray distance of 700 to 1200 mm and a collector angle of 20 to 45 ° to obtain a preform;
And a fourth step of densifying the aluminum-based alloy preform by a densifying means.   The manufacturing method according to claim 6, wherein the fourth step includes a step of performing hot isostatic pressing at a temperature of 400 to 600 ° C under a pressure of 80 MPa or more.