Copper-gallium target material and preparation method thereof

Abstract

The invention provides a preparation method of a copper-gallium target material, which comprises the following steps: carrying out vacuum melting by taking a high-purity copper block and high-purity gallium as raw materials with the gallium content of 35-55wt.%, casting the raw materials into a mold after the melting is completed, and cooling to obtain a copper-gallium alloy; the temperature of the vacuum melting is 800 to 900 DEG C; the copper-gallium alloy is subjected to spray powdering, and copper-gallium alloy powder is obtained; and the copper-gallium alloy powder is subjected to hot isostatic pressing and cooling, and the copper-gallium target material is obtained. The high-gallium copper-gallium alloy is prepared by adopting a vacuum casting method, then the alloy powder is prepared by adopting an aerial fog method, and the copper-gallium target material with high density and good component uniformity is further prepared through hot isostatic pressing sintering and annealing.

Description

Technical Field

[0001] The present invention relates to the technical field of material preparation, and more specifically, to a copper-gallium target material and a preparation method thereof. Background Art

[0002] Copper-gallium alloy is the basic material of CIG (copper indium gallium) and CIGS (copper indium gallium selenide) thin-film solar materials. In order to adjust and precisely control the composition ratio of each element in prefabricated films such as CIG and CIGS, and obtain thin films with a high Ga content, it is necessary to use copper-gallium alloy targets with a high Ga content as raw materials. For copper-gallium alloys and targets with high Ga content (Ga content greater than 35%), the material becomes brittle when the Ga content is high, and improvements need to be made in the preparation process. At present, the manufacturing methods of Cu-Ga targets are mainly divided into direct melting (casting) method and powder metallurgy method. Among them, the casting method has the disadvantages of component segregation and the inability to eliminate pores. The general powder metallurgy method also has the disadvantages of low density and easy cracking. Summary of the invention

[0003] In response to the above technical problems, the present application provides a method for preparing a copper-gallium target.

[0004] To achieve the above objectives, this application proposes the following technical solutions: In a first aspect, a method for preparing a copper-gallium target is provided, comprising: High-purity copper block and high-purity gallium are used as raw materials for vacuum smelting, wherein the gallium content in the raw materials is 35-55wt.%, and after smelting, the raw materials are cast into a mold for cooling to obtain a copper-gallium alloy; the vacuum smelting temperature is 800-900°C; Spraying the copper-gallium alloy to obtain copper-gallium alloy powder; The copper-gallium alloy powder is hot isostatically pressed and cooled to obtain a copper-gallium target.

[0005] Preferably, the temperature of the hot isostatic pressing is 600-700° C.; the pressure of the hot isostatic pressing is 150-200 MPa; and the heat preservation and pressure holding time of the hot isostatic pressing is 90-120 min.

[0006] Preferably, the vacuum degree of the vacuum melting is less than 0.2 Pa; and the time of the vacuum melting is 60 to 90 minutes.

[0007] Preferably, the atomization temperature of the spray powder is 1000-1100° C.; the atomization pressure of the spray powder is 10-12 bar; and the atomization rate of the spray powder is 1-3 kg / min.

[0008] Preferably, the particle size of the copper-gallium alloy powder is not greater than 60 mesh.

[0009] Preferably, the method further comprises: annealing the copper-gallium target.

[0010] Preferably, the annealing temperature is 300-400° C. and the annealing time is 2-3 hours.

[0011] In a second aspect, a copper-gallium target is provided, which is prepared using the aforementioned preparation method.

[0012] Compared with the prior art, one or more of the above technical solutions can achieve at least one of the following beneficial effects: A high-gallium copper-gallium alloy is prepared by vacuum casting, the alloy powder is prepared by aerosol method, and a high-density copper-gallium target with good component uniformity is further prepared by hot isostatic pressing and sintering. DETAILED DESCRIPTION

[0013] When preparing copper-gallium targets with high gallium content (above 35wt.%), the applicant found that this target is prone to material segregation compared with copper-gallium targets with low gallium content. In response to this phenomenon, the applicant has developed a new method for preparing copper-gallium targets after research. This method can prepare copper-gallium targets with high gallium content and good uniformity of material composition.

[0014] The present invention provides a method for preparing a copper-gallium target, comprising: High-purity copper blocks and high-purity gallium are used as raw materials for vacuum smelting, wherein the gallium content is 35-55wt.%, and after smelting, they are cast into a mold for cooling to obtain a copper-gallium alloy; the vacuum smelting temperature is 800-900°C; Spraying the copper-gallium alloy to obtain copper-gallium alloy powder; The copper-gallium alloy powder is hot isostatically pressed and cooled to obtain a copper-gallium target.

[0015] The temperature of the vacuum melting is 800-900°C, for example, 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C, 900°C, etc.

[0016] It is worth mentioning that in the present preparation method, casting is performed immediately after smelting is completed, that is, the casting temperature is the vacuum melting temperature, which is 800-900°C, for example, 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C, 900°C, etc.

[0017] In some preferred embodiments, the temperature of the hot isostatic pressing is 600-700°C, specifically, it can be 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, 660°C, 670°C, 680°C, 690°C, 700°C, etc.

[0018] In some preferred embodiments, the hot isostatic pressing pressure is 150-200 MPa, for example, 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, etc.

[0019] In some preferred embodiments, the heat preservation and pressure holding time of the hot isostatic pressing is 90 to 120 min, for example, 90 min, 95 min, 100 min, 105 min, 110 min, 115 min, 120 min, etc.

[0020] In some preferred embodiments, the vacuum degree of the vacuum melting is less than 0.2 Pa; the time of the vacuum melting is 60 to 90 min, for example, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min, 90 min, etc.

[0021] The gallium content in the raw materials of the high-purity copper block and high-purity gallium is 35-55wt%, for example, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt% and the like.

[0022] In some preferred embodiments, the atomization temperature of the spray powder is 1000-1100° C.; the atomization pressure of the spray powder is 10-12 bar; and the atomization rate of the spray powder is 1-3 kg / min.

[0023] In some preferred embodiments, the particle size of the copper-gallium alloy powder is no greater than 60 mesh.

[0024] In some preferred embodiments, the method further includes: annealing the copper gallium target; preferably, the annealing temperature is 300-400°C, for example, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, etc.; the annealing time is 2-3h, for example, 2h, 2.2h, 2.5h, 2.8h, 3h, etc.

[0025] The present invention also provides a copper-gallium target material, which is prepared by the above-mentioned preparation method.

[0026] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously in combination with preferred embodiments below, but the protection scope of the present invention is not limited to the following specific embodiments.

[0027] Example 1 Vacuum casting: high-purity copper blocks and high-purity gallium are placed in a vacuum melting furnace in proportion, with a gallium content of 55wt%, a melting temperature of 800℃, a melting time of 70min, and a vacuum degree of <0.2pa. After melting, they are cast into a mold and cooled.

[0028] Spray powdering: the copper-gallium alloy ingot is placed in a spray powdering furnace for spray powdering, wherein the parameters are an atomization temperature of 1050° C., an atomization pressure of 10 bar, and an atomization rate of 3 kg / min, to obtain a copper-gallium alloy powder with a particle size of less than 60 mesh.

[0029] Hot isostatic pressing: the copper-gallium powder is packed into a package and then hot isostatic pressing is performed, wherein the temperature is 600°C, the pressure is 150 MPa, the heat preservation time is 120 minutes, and the temperature is lowered with the furnace after heat preservation.

[0030] Annealing: After the above is taken out of the furnace, the cladding is removed and annealed at 400°C for 3 hours to obtain the copper-gallium alloy target as the furnace cools down.

[0031] Comparative Example 1 The difference between this comparative example and Example 1 is that the melting temperature in the vacuum casting step is different, and the melting temperature is 770°C.

[0032] Comparative Example 2 Vacuum melting-spray powdering: high-purity copper blocks and high-purity gallium are placed in a vacuum melting furnace in proportion, wherein the gallium content is 55wt%, wherein the melting temperature is 800℃, the melting time is 55min, the vacuum degree is <0.2pa, and the alloy liquid is obtained. The alloy liquid is sprayed into powder, wherein the parameters are an atomization temperature of 1050℃, an atomization pressure of 10bar, and an atomization rate of 3kg / min.

[0033] Hot isostatic pressing: the copper-gallium powder is packed into a package and then hot isostatic pressing is performed, wherein the temperature is 600°C, the pressure is 150 MPa, the heat preservation time is 120 minutes, and the temperature is lowered with the furnace after heat preservation.

[0034] Annealing: After the above is taken out of the furnace, the cladding is removed and annealed at 400°C for 3 hours. The temperature is then lowered to the copper-gallium alloy target. It is observed that there is metal on the surface of the target. After testing, the metal is gallium, indicating that the reaction is incomplete and component segregation has occurred.

[0035] Example 2 Vacuum casting: high-purity copper blocks and high-purity gallium are placed in a vacuum melting furnace in proportion, with a gallium content of 35wt%, a melting temperature of 900°C, a melting time of 60min, and a vacuum degree of <0.2pa. After melting, they are cast into a mold and cooled.

[0036] Spray powdering: the copper-gallium alloy ingot is placed in a spray powdering furnace for spray powdering, wherein the parameters are an atomization temperature of 1100° C., an atomization pressure of 12 bar, and an atomization rate of 2 kg / min, to obtain a copper-gallium alloy powder with a particle size of less than 60 mesh.

[0037] Hot isostatic pressing: The copper-gallium powder is packaged in a package and then hot isostatic pressing is performed, wherein the temperature is 700°C, the pressure is 180 MPa, and the heat and pressure holding time is 90 minutes. After cooling down, the temperature is cooled down along with the furnace.

[0038] Annealing: After the above is taken out of the furnace, the cladding is removed and annealed at 300°C for 3 hours to obtain the copper-gallium alloy target as the furnace cools down.

[0039] Example 3 Vacuum casting: high-purity copper blocks and high-purity gallium are placed in a vacuum melting furnace in proportion, wherein the gallium content is 45wt%, the melting temperature is 850℃, the melting time is 70min, the vacuum degree is <0.2pa, and after melting, they are cast into a mold and cooled.

[0040] Spray powdering: The copper-gallium alloy ingot is placed in a spray powdering furnace for spray powdering, wherein the parameters are an atomization temperature of 1000° C., an atomization pressure of 11 bar, and an atomization rate of 1 kg / min, to obtain a copper-gallium alloy powder with a particle size of less than 60 mesh.

[0041] Hot isostatic pressing: The copper-gallium powder is packaged in a package and then hot isostatic pressing is performed, wherein the temperature is 650°C, the pressure is 160 MPa, and the heat and pressure holding time is 100 minutes. After cooling down, the temperature is reduced along with the furnace.

[0042] Annealing: After the above is taken out of the furnace, the cladding is removed and annealed at 350°C for 2 hours, and the copper-gallium alloy target is obtained as the furnace is cooled.

[0043] The relative density and composition uniformity of the target materials obtained in each embodiment and comparative example are shown in Table 1.

[0044] Example 4 The difference between this embodiment and embodiment 1 is that the temperature of hot isostatic pressing is different, and the temperature of hot isostatic pressing is 580°C.

[0045] Example 5 The difference between this embodiment and embodiment 1 is that the temperature of hot isostatic pressing is different, and the temperature of hot isostatic pressing is 750°C.

[0046] Example 6 The difference between this embodiment and embodiment 1 is that the hot isostatic pressing time is different, and the hot isostatic pressing time is 60 minutes.

[0047] Example 7 The difference between this embodiment and embodiment 1 is that the hot isostatic pressing time is different, and the hot isostatic pressing time is 150 minutes.

[0048] It can be seen from Table 1 that the target materials prepared in Examples 1 to 3 have uniform composition and a relative density higher than 98%; the targets prepared in Comparative Examples 1 and 2 are segregated, and elemental gallium appears on the surface of the target material obtained in Comparative Example 2; the target materials obtained in Examples 4 to 7 have uniform composition, but the relative density (i.e., compactness) is reduced.

[0049] Table 1 The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a copper-gallium target, characterized in that: include: High-purity copper block and high-purity gallium are used as raw materials for vacuum smelting, wherein the gallium content in the raw materials is 35-55wt.%, and after smelting, the raw materials are cast into a mold for cooling to obtain a copper-gallium alloy; the vacuum smelting temperature is 800-900°C; Spraying the copper-gallium alloy to obtain copper-gallium alloy powder; The copper-gallium alloy powder is hot isostatically pressed and cooled to obtain a copper-gallium target.

2. The method for preparing a copper-gallium target according to claim 1, characterized in that: The temperature of the hot isostatic pressing is 600-700° C.; the pressure of the hot isostatic pressing is 150-200 MPa; and the heat preservation and pressure holding time of the hot isostatic pressing is 90-120 minutes.

3. The method for preparing a copper-gallium target according to claim 1, characterized in that: The vacuum degree of the vacuum melting is less than 0.2 Pa; and the time of the vacuum melting is 60 to 90 minutes.

4. The method for preparing a copper-gallium target according to claim 1, characterized in that: The atomization temperature of the spray powder is 1000-1100° C.; the atomization pressure of the spray powder is 10-12 bar; and the atomization rate of the spray powder is 1-3 kg / min.

5. The method for preparing a copper-gallium target according to claim 1, characterized in that: The particle size of the copper-gallium alloy powder is no greater than 60 meshes.

6. The method for preparing a copper-gallium target according to any one of claims 1 to 5, characterized in that: Also includes: The step of annealing the copper gallium target.

7. The method for preparing a copper-gallium target according to claim 6, characterized in that: The annealing temperature is 300-400° C. and the annealing time is 2-3 hours.

8. Copper gallium target, characterized in that The method is described in any one of claims 1 to 7.

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