Silicon aluminum target and method for manufacturing the same

Abstract

The application discloses a silicon-aluminum target material and a preparation method thereof, and belongs to the field of metal processing. The method adopts a plasma spraying process. When the product is prepared, through special protection design of a rotating spraying back pipe and selection of powder raw materials with special particle sizes, the prepared product can have high deposition rate and high production efficiency on the basis of high density and no obvious cracks.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of metal processing, in particular to a silicon-aluminum target material and a preparation method thereof. BACKGROUND

[0002] The silicon-aluminum target material prepared by the plasma spraying process can be prepared in any size according to actual needs without size and space limitations, and can theoretically well replace the existing powder pressing and sintering process. However, the target material prepared by this process has the problems of low density and low deposition rate, and the product surface, especially the end position, is prone to crack due to stress concentration, the controlled factors are complex, and the production efficiency and product quality are difficult to meet the standard requirements of industrial mass production. SUMMARY

[0003] Based on the defects of the prior art, the purpose of the present application is to provide a preparation method of a silicon-aluminum target material, which still uses the plasma spraying process, but when preparing the product, through the special protection design of the rotating spraying back pipe and the selection of special particle size of the powder raw material, the prepared product can have high deposition rate and high production efficiency on the basis of high density and no obvious cracks.

[0004] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0005] A preparation method of a silicon-aluminum target material, comprising the following steps:

[0006] (1) setting a rotating spraying back pipe, sandblasting the rotating spraying back pipe, and then setting a NiAl coating on the spraying position of the rotating spraying back pipe by arc spraying treatment;

[0007] (2) wrapping the rotating spraying back pipe with heat-resistant tape at both ends where the NiAl coating is located, and then covering the wrapped part of the heat-resistant tape with a protective sleeve;

[0008] (3) placing the mixed powder into a plasma spraying machine, and then spraying the silicon-aluminum target material on the rotating spraying back pipe; the mixed powder comprises silicon powder and aluminum powder, the mass ratio of the silicon powder to the aluminum powder is (91:9) to (95:5), the particle size of the silicon powder is 45 to 150 μm, and the mass content of the silicon powder with a particle size of 75 to 150 μm accounts for 30 to 50 wt%;

[0009] (4) after the silicon-aluminum target material is sprayed to a predetermined thickness, cooling, the preparation of the silicon-aluminum target material is completed.

[0010] The target material preparation by the plasma spraying process does not need to consider the size of the product, but compared with the traditional powder hot-pressing sintering process, the existing plasma spraying process is mostly implemented in the laboratory in a low-power and low-yield mode (i.e., only the quality of the target material is considered, and the actual production efficiency of the target material is not considered), if the plasma spraying process is implemented in a factory standard for batch production, the silicon-aluminum target material prepared by the plasma spraying process has low density and low deposition rate, and it is difficult to reach the commercial standard in terms of production efficiency and the quality of the produced target material, and in the plasma spraying process, cracks often occur on the surface of the produced silicon-aluminum target material due to stress concentration, and the product cannot meet the use requirements.

[0011] Therefore, in the technical scheme of the present application, without considering setting additional processes or control parameters, first, powder with a special size distribution is selected as the raw material for plasma spraying, then a NiAl coating with a bottoming effect is pre-set on the deposited rotary spraying back pipe, and heat-resistant adhesive tape is wound around the two ends, and finally a sheath is used to cover the treated part, in the plasma spraying process, the powder particles can be fully melted and deposited on the back pipe, the deposition rate is high, the density of the deposited particles is high, the heat-resistant adhesive tape wound around plays a transition role between the NiAl coating and the non-coating area, and the powder particles will not cause stress concentration effect when deposited, so that cracks will not occur on the two ends of the formed target material and extend to the central part, and the surface of the prepared target product will not have obvious cracks.

[0012] Preferably, the thickness of the NiAl coating is 0.5-1.3 mm.

[0013] By setting the NiAl coating with a bottoming effect on the rotary spraying back pipe, the particles generated by the plasma spraying can be uniformly deposited on the back pipe and have high deposition density, and the above thickness can make the product have higher density and uniformity without affecting the production efficiency.

[0014] Preferably, the heat-resistant adhesive tape is a Teflon tape, and more preferably a 3J76B Teflon tape.

[0015] More preferably, when the heat-resistant adhesive tape is wound around one end of the rotary spraying back pipe provided with the NiAl coating, the width of the tape is 12-14 mm, the length is 415-420 mm, and the thickness of the tape after winding is 0.1-0.3 mm.

[0016] Preferably, the sheath is a stainless steel ring-shaped sheath with a thickness of 1.5-2.5 mm, and when the sheath covers the heat-resistant adhesive tape, the parallel distance between the heat-resistant adhesive tape and the uncovered area of the rotary spraying back pipe is 3-6 mm.

[0017] The heat-resistant adhesive tape and the sheath are arranged, so that the stress concentration problem caused by plasma spraying deposition layer when spraying at the junction of the NiAl layer and the non-NiAl layer area can be avoided, and then the crack from the area extends to the central part, so that the quality of the target material obtained by plasma spraying is effectively ensured.

[0018] Preferably, the purity of the silicon powder is greater than or equal to 3N, and the purity of the aluminum powder is greater than or equal to 2N8.

[0019] More preferably, the particle size of the aluminum powder is 50-120 μm.

[0020] Preferably, in the step (1), the outer diameter of the rotary spraying back tube is 120-150 mm, and the length is 3000-3500 mm.

[0021] Preferably, in the step (3), the working power during the plasma spraying is 30-35 kW, the moving speed of the spraying gun used in the plasma spraying is 35-45 mm / min, the spraying distance is 100-150 mm, the rotating speed of the rotary spraying back tube is 200-300 rpm, and the powder feeding amount of the mixed powder is 190-200 g / min, and the gas flow rate is 3.5-4.5 nL / min.

[0022] More preferably, the spraying gun is provided with a plasma generation pipeline, and a mixed gas is arranged in the plasma generation pipeline, the mixed gas comprising argon and hydrogen, the flow rate of the argon is 2600-2700 nL / h, and the flow rate of the hydrogen is 450-500 nL / h.

[0023] In the argon-hydrogen mixed gas connected with the spraying gun, the argon generates plasma under the action of an electric field, the hydrogen has a combustion-supporting effect, and the titanium dioxide powder fed to the spraying gun is deposited under the action.

[0024] Another object of the present application is to provide a silicon-aluminum target material prepared by the preparation method of the silicon-aluminum target material.

[0025] Preferably, the thickness of the silicon-aluminum target material is greater than or equal to 9 mm.

[0026] Preferably, the density of the silicon-aluminum target material is 2-2.5 g / cm 3 , the resistivity is 0.015-0.020 Ω / cm, and the deposition rate is 30-35%.

[0027] The present application has the beneficial effect that the present application provides a preparation method of a silicon-aluminum target material, which adopts a plasma spraying process, and through the special design of the rotary spraying back tube and the selection of the special particle size of the powder raw material during product preparation, the prepared product has a high deposition rate and high production efficiency on the basis of high density and no obvious cracks.

[0028] Drawings

[0029] Figure 1 The setting diagram of the rotary spraying back tube of the present application. DETAILED DESCRIPTION

[0030] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below in combination with specific examples and comparative examples, the purpose of which is to understand the content of the present application in detail, rather than to limit the present application. All other examples obtained by the ordinary skilled in the art without making creative efforts belong to the protection scope of the present application. The experimental reagents and instruments involved in the implementation of the present application are all common ordinary reagents and instruments unless otherwise specified.

[0031] Example 1

[0032] The embodiment of the silicon-aluminum target material and the preparation method thereof of the present application, the preparation method of the silicon-aluminum target material, comprises the following steps:

[0033] (1) Set the outer diameter of the rotary spraying back tube to 133 mm and the length to 3191 mm, sandblast the rotary spraying back tube, and then set a 1 mm thick NiAl coating as a primer layer on the spraying site of the rotary spraying back tube by arc spraying treatment;

[0034] (2) Wrap the rotary spraying back tube with heat-resistant tape at both ends where the NiAl coating is located, and then cover the wrapped part of the heat-resistant tape (also known as high-temperature tape) with a sheath, wherein the length of the sheath covering the primer layer (i.e. the parallel distance between the heat-resistant tape and the uncovered area of the rotary spraying back tube) is 5 mm; as shown in the figure; the heat-resistant tape is 3J76B Teflon tape, and the wrapping width is 13 mm, the length is 417.62 mm, and the wrapping thickness is 0.2 mm; the sheath is a 304 stainless steel ring sheath with a thickness of 2 mm; Figure 1

[0035] (3) Put 3N silicon powder and 2N8 aluminum powder into a mixer according to a mass ratio of 93:7, mix for 6 h, dry at 60℃ for 6 h, and then put the obtained mixed powder into an SN-DQPT-4600L plasma spraying machine, and then plasma spray the silicon-aluminum target material on the rotary spraying back tube; the silicon powder is sieved, and the particle size is 45-150 μm, wherein the mass content of the silicon powder with a particle size of 75-150 μm accounts for 48 wt%, the average particle size of this part of the silicon powder is 110 μm, and the particle size of the remaining silicon powder is 45-75 μm, the average particle size of this part of the silicon powder is 60 μm; the particle size of the aluminum powder is 50-120 μm, and the average particle size is 85 μm;

[0036] ​The power is set to 33.4kW during the plasma spraying, the spraying gun moves back and forth, the rotary spraying back tube rotates from the shaft, the moving speed of the spraying gun is 42mm / min, the spraying distance is 140mm, the rotating speed of the rotary spraying back tube is 240rpm, the powder feeding amount of the mixed powder is 190g / min, the powder feeding gas flow is 4nL / min, the spraying gun is provided with a plasma generation pipeline, the plasma generation pipeline is provided with mixed gas, the mixed gas includes argon and hydrogen, the argon flow is 2600nL / h, and the hydrogen flow is 500nL / h.

[0037] (4) After the silicon-aluminum target is sprayed to a predetermined thickness of 9.1mm, cooling is performed, and the preparation of the silicon-aluminum target is completed.

[0038] Example 2

[0039] The embodiment of the silicon-aluminum target and the preparation method thereof in the application only differs from the embodiment 1 in that the thickness of the NiAl coating layer is 1.2mm; the rotary spraying back tube provided with the NiAl coating layer is wrapped by using heat-resistant adhesive tape at both ends, and then the wrapped part of the heat-resistant adhesive tape is covered by using a sheath, and the length of the coating layer covered by the sheath is 6mm; the power is set to 34kW during the plasma spraying; and the silicon-aluminum target is deposited to a predetermined thickness of 9.2mm.

[0040] Example 3

[0041] The embodiment of the silicon-aluminum target and the preparation method thereof in the application only differs from the embodiment 1 in that the mass ratio of the silicon powder and the aluminum powder in the mixed powder is 94:6.

[0042] Example 4

[0043] The embodiment of the silicon-aluminum target and the preparation method thereof in the application only differs from the embodiment 1 in that the silicon powder is subjected to a screening treatment, the particle size is 45-150μm, the mass content of the silicon powder with a particle size of 75-150μm accounts for 45wt%, the average particle size of the part of the silicon powder is 120μm, the particle size of the remaining silicon powder is 45-75μm, and the average particle size of the part of the silicon powder is 50μm; and the particle size of the aluminum powder is 50-120μm, and the average particle size is 90μm.

[0044] Example 5

[0045] The embodiment of the silicon-aluminum target and the preparation method thereof according to the present application is different from the embodiment 1 only in that the silicon powder is subjected to a screening treatment, and the particle size is 45-150 μm, wherein the mass content of the silicon powder with a particle size of 75-150 μm accounts for 42 wt%, the average particle size of the silicon powder in this part is 130 μm, the particle size of the remaining silicon powder is 45-75 μm, and the average particle size of the silicon powder in this part is 55 μm; and the particle size of the aluminum powder is 50-120 μm, and the average particle size is 100 μm.

[0046] Comparative example 1

[0047] The embodiment of the silicon-aluminum target and the preparation method thereof is different from the embodiment 1 only in that the rotary spraying back pipe is not wrapped with a heat-resistant tape and covered with a sheath after the NiAl coating is arranged, and the silicon-aluminum target is deposited to a predetermined thickness of 9.4 mm.

[0048] Comparative example 2

[0049] The embodiment of the silicon-aluminum target and the preparation method thereof is different from the embodiment 1 only in that the rotary spraying back pipe is not wrapped with a heat-resistant tape and covered with a sheath after the NiAl coating is arranged, and the silicon-aluminum target is deposited to a predetermined thickness of 9.4 mm.

[0050] Comparative example 3

[0051] The embodiment of the silicon-aluminum target and the preparation method thereof is different from the embodiment 1 only in that the silicon powder is subjected to a screening treatment, and the particle size is 20-120 μm, wherein the mass content of the silicon powder with a particle size of 50-120 μm accounts for 48 wt%, the average particle size of the silicon powder in this part is 90 μm, the particle size of the remaining silicon powder is 20-50 μm, and the average particle size of the silicon powder in this part is 30 μm; and the silicon-aluminum target is deposited to a predetermined thickness of 9.4 mm.

[0052] Comparative example 4

[0053] The embodiment of the silicon-aluminum target and the preparation method thereof is different from the embodiment 1 only in that the silicon powder is subjected to a screening treatment, and the particle size is 70-180 μm, wherein the mass content of the silicon powder with a particle size of 120-180 μm accounts for 48 wt%, the average particle size of the silicon powder in this part is 150 μm, the particle size of the remaining silicon powder is 70-120 μm, and the average particle size of the silicon powder in this part is 85 μm.

[0054] Effect example 1

[0055] In order to verify the effect of the silicon-aluminum target prepared by the preparation method according to the present application, the products of each embodiment and comparative example are tested in terms of density (Archimedes method), average resistivity (directly tested by a four-probe resistivity meter), and deposition rate (directly counted by weight), and whether cracks appear on the surface of the product is observed (typically, whether cracks extending to the center appear at both ends of the target), and the test results are counted in Table 1.

[0056] Table 1

[0057]

[0058] As can be seen from Table 1, the silicon-aluminum target material prepared by the preparation method has high quality, and the density of the target material can reach 2.220 g / cm 3 The average resistivity can be maintained in the range of 0.015-0.016 Ω / cm, the deposition rate is more than 32%, and there is no obvious crack defect in appearance.

[0059] As can be seen from Example 1, Examples 4-5, and Comparative Examples 3-4, the particle size of the powder used in plasma spraying has a great influence on the performance of the prepared product, especially the silicon powder which accounts for a large proportion. When the particle size of the silicon powder used is too small or too large, the particles cannot be fully uniform during melting and deposition, which affects the deposition rate of the prepared target product and the density of the obtained product. The density of the product of Comparative Example 3 is relatively high, but the deposition success rate is low due to the use of too large silicon powder particles, and the deposition rate is low. The silicon powder used in the preparation of the product of Comparative Example 4 is too small, not only the deposition rate is low, but also the density of the obtained target product is not as expected.

[0060] As can be seen from Example 1, Comparative Examples 1 and 2, when the rotating spraying back tube is not provided with any device, and the mixed powder defined in the application is used for plasma spraying, stress concentration and uneven stress are prone to occur when the particles are deposited on the base coating and the non-base coating at both ends, so that cracks occur in the prepared product from both ends and extend to the central part. On this basis, the transition area between the base coating and the non-base coating is treated by mixing with the heat-resistant adhesive tape in the method of Comparative Example 2, but this method will cause the particles to be deposited on the area and completely cover the heat-resistant adhesive tape, which cannot still relieve stress in the subsequent deposition process, and the prepared target product still has cracks. Only the method of Example 1 which simultaneously provides heat-resistant adhesive tape winding and sheath covering can effectively avoid stress concentration problems during the whole particle deposition process, so that the prepared target product has no cracks.

[0061] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the application and do not limit the protection scope of the application. Although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the application.

Claims

1. A method of producing a silicon aluminum target material, characterized by, The method comprises the following steps: (1) setting a rotary spraying back tube, sandblasting the rotary spraying back tube, and then setting a NiAl coating on the spraying part of the rotary spraying back tube by arc spraying treatment; (2) wrapping the two ends of the rotary spraying back tube provided with the NiAl coating with heat-resistant adhesive tape, and then covering the wrapped part of the heat-resistant adhesive tape with a sheath; (3) placing mixed powder into a plasma spraying machine, and then plasma spraying the mixed powder on the rotary spraying back tube to form a silicon-aluminum target; the working power during the plasma spraying is 30-35 kW, the moving speed of the spray gun during the plasma spraying is 35-45 mm / min, the spraying distance is 100-150 mm, the rotating speed of the rotary spraying back tube is 200-300 rpm, the powder feeding amount of the mixed powder is 190-200 g / min, and the gas flow is 3.5-4.5 nL / min; the mixed powder comprises silicon powder and aluminum powder, and the mass ratio of the silicon powder to the aluminum powder is (91:9)-(95:5); the silicon powder is sieved, and the particle size is 45-150 μm, wherein the mass content of the silicon powder with a particle size of 75-150 μm accounts for 48 wt%, the average particle size of the silicon powder with a particle size of 75-150 μm is 110 μm, the particle size of the remaining silicon powder is 45-75 μm, and the average particle size of the remaining silicon powder is 60 μm; the particle size of the aluminum powder is 50-120 μm, and the average particle size is 85 μm; alternatively, the silicon powder is sieved, and the particle size is 45-150 μm, wherein the mass content of the silicon powder with a particle size of 75-150 μm accounts for 45 wt%, the average particle size of the silicon powder with a particle size of 75-150 μm is 120 μm, the particle size of the remaining silicon powder is 45-75 μm, and the average particle size of the remaining silicon powder is 50 μm; the particle size of the aluminum powder is 50-120 μm, and the average particle size is 90 μm; alternatively, the silicon powder is sieved, and the particle size is 45-150 μm, wherein the mass content of the silicon powder with a particle size of 75-150 μm accounts for 42 wt%, the average particle size of the silicon powder with a particle size of 75-150 μm is 130 μm, the particle size of the remaining silicon powder is 45-75 μm, and the average particle size of the remaining silicon powder is 55 μm; the particle size of the aluminum powder is 50-120 μm, and the average particle size is 100 μm; (4) after the silicon-aluminum target is sprayed to a predetermined thickness, cooling, and thus the preparation of the silicon-aluminum target is completed.

2. The method of claim 1, wherein the silicon aluminum target is prepared by the steps of: The thickness of the NiAl coating is 0.5-1.3 mm. ​ 3. A silicon-aluminum target prepared by the method according to any one of claims 1-2.

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