A low-oxygen-content fe-cr-al alloy powder, a target material, and a method for producing the powder and the target material

Abstract

The application belongs to the technical field of alloy target materials, and discloses a low-oxygen-content iron-chromium-aluminum alloy powder, a target material, and a preparation method of the powder and the target material. The preparation method of the low-oxygen-content iron-chromium-aluminum alloy powder comprises the following steps: step 1: liquid iron, chromium, and aluminum are sequentially subjected to gas-water combined atomization granulation, drying, and screening to obtain iron powder A, chromium powder A, and aluminum powder A; step 2: the iron powder A, the chromium powder A, and the aluminum powder A are sequentially subjected to ball milling and centrifugal separation in an inert gas atmosphere to obtain iron powder B, chromium powder B, and aluminum powder B; and step 3: the iron powder B, the chromium powder B, and the aluminum powder B are mixed in an inert gas atmosphere to obtain the low-oxygen-content iron-chromium-aluminum alloy powder. In the gas-water combined atomization granulation of step 1, the gas used for gas atomization is an inert gas, and the liquid used for water atomization is a mixed liquid of water and a micro-etching agent. The iron powder A, the chromium powder A, and the aluminum powder A are added with isopropyl alcohol or acetone for ball milling in an inert gas atmosphere.

Description

Technical Field

[0001] This invention belongs to the field of alloy target technology, specifically relating to a low-oxygen-content iron-chromium-aluminum alloy powder, a target, and a method for preparing the powder and the target. Background Technology

[0002] Physical vapor deposition (PVD) is widely used in high-end industries such as optics, electronics, and information, including integrated circuits, liquid crystal displays, industrial glass, camera lenses, information storage, shipbuilding, and chemicals. The alloy targets used in physical vapor deposition are one of the most important raw materials in the manufacturing process of integrated circuits and liquid crystal displays.

[0003] With the continuous development of physical vapor deposition technology, the demand for and quality requirements of alloy targets are increasing. The finer the grains, the more uniform the composition and structure of the alloy target, and the smaller its surface roughness, the more uniform the thin film formed on the silicon wafer by physical vapor deposition. In addition, the purity of the formed film is also closely related to the purity of the alloy target. Therefore, the quality of the film after physical vapor deposition mainly depends on factors such as the purity, density, grain size, and microstructure of the alloy target.

[0004] Iron-chromium-aluminum alloys, as a new type of alloy sputtering material, are widely used in industries such as integrated circuits and liquid crystal displays due to their low resistivity, good thermal stability and oxidation resistance. Therefore, iron-chromium-aluminum alloy sputtering materials have become one of the research hotspots for sputtering materials.

[0005] Existing technologies rarely disclose the technological development and preparation routes of iron-chromium-aluminum alloy targets. A relatively relevant example is D1: Chinese Patent 202210176058.6, which discloses a high-strength chromium-aluminum alloy target and its preparation method. This chromium-aluminum alloy target contains aluminum and chromium, with aluminum accounting for no less than 15% by weight. Its characteristics include extremely high strength or toughness, ease of processing into complex shapes, and resistance to chipping or breakage. The main processes for preparing this target include mixing chromium powder, aluminum powder, and other doped powders, packaging and degassing, hot isostatic pressing, and machining.

[0006] The aforementioned patent application is for the production of chromium-aluminum alloy targets. It employs techniques such as encapsulation degassing and hot isostatic pressing to prepare high-strength chromium-aluminum alloy targets. However, this technology is not suitable for iron-chromium-aluminum alloy targets because the addition of iron powder alters the characteristics of the target, thereby increasing the requirements for properties such as density. The chromium-aluminum alloy targets produced by the preparation method in the aforementioned patent application do not meet customer requirements in terms of density and other properties. This is because the encapsulation degassing technique used in the aforementioned technology cannot effectively reduce the oxygen content in the target, and the oxygen in the target mainly comes from the oxygen in the alloy powder.

[0007] Oxygen in powder, especially the thickness, distribution, and content of the oxide film on the particle surface, has a significant impact on the performance of the target material and the sputtered film. A thick and continuously distributed oxide film can hinder the ceramization process during sintering, reduce the interfacial bonding strength between particles, and impede the spreading and wetting properties of the liquid phase. This directly affects the densification degree, strength, toughness, and other performance indicators of the sintered body, thereby affecting the overall mechanical properties of the target material and the performance of the coated film.

[0008] Therefore, before preparing iron-chromium-aluminum alloy targets, it is necessary to reduce the oxygen content in the iron-chromium-aluminum alloy powder and even remove the oxide film, so that the prepared iron-chromium-aluminum alloy targets have high comprehensive performance.

[0009] Based on this, D2: Chinese Patent 201810668532.0 discloses a method for producing hydrogen energy by physically ball milling metal powder. The method involves placing the metal powder in a vacuum ball mill, adding a small amount of metal chloride aqueous solution and an additive, and performing wet ball milling under hydrogen protection. The metal powder is then subjected to ball milling, which removes the oxide layer or the hydroxide generated in the reaction. This method, by applying an additive and physically ball milling the metal powder during hydrogen production, effectively ensures the hydrogen production yield and reaction rate by removing the oxide / hydroxide film generated in the hydrolysis hydrogen production reaction from the metal powder. Furthermore, the entire process is simple to operate, the reaction is neutral, the equipment requirements are low, and the production cost is low.

[0010] Meanwhile, D3: Chinese Patent 201810967393.1 discloses a high-energy ball milling enhanced activated aluminum hydrogen-producing material and its preparation method; the hydrogen-producing material comprises the following components in parts by weight: 80-95 parts aluminum powder, 5-20 parts of at least one of anhydrous citric acid or glacial acetic acid, and 0.8-1.2 parts organic solvent. This invention uses high-energy ball milling to enhance contact and collision with aluminum powder, achieving the purpose of efficiently removing the alumina passivation layer and improving the activity of aluminum powder. After cleaning with anhydrous ethanol and atomizing and drying, activated aluminum powder material is obtained, which can effectively react with water to produce hydrogen.

[0011] Both D2 and D3 disclose that ball milling combined with additives can effectively destroy the oxide film of metal powders, and therefore can be used in the preparation of iron-chromium-aluminum alloy powders with low oxygen content. However, experiments have found that the technical solution of simply using ball milling and additives to destroy the oxide film of iron, chromium, and aluminum powders and then using it to prepare iron-chromium-aluminum alloy targets has some drawbacks: ball milling and additives do not completely destroy the iron, chromium, and aluminum powders. The technical solutions disclosed in D2 and D3 are only for destroying the oxide film to increase the reaction rate of metal powders with hydrogen or water. As long as the oxide film is partially destroyed, the reaction rate can be effectively increased. However, the preparation of the target requires the iron-chromium-aluminum alloy powder to have a lower oxygen content, which requires the complete destruction and removal of the oxide film of the iron, chromium, and aluminum powders. Therefore, simply using ball milling and additives to destroy the oxide film of iron, chromium, and aluminum powders is not suitable for the preparation of iron-chromium-aluminum alloy targets.

[0012] Therefore, it is necessary to develop a method for preparing iron-chromium-aluminum alloy powder with low oxygen content and a method for preparing iron-chromium-aluminum alloy target material with low oxygen content. Summary of the Invention

[0013] One of the objectives of this invention is to provide a method for preparing iron-chromium-aluminum alloy powder with low oxygen content, so as to solve the technical problem that the existing technology does not completely destroy and remove the oxide film of iron, chromium and aluminum powder, and cannot provide iron-chromium-aluminum alloy powder with lower oxygen content.

[0014] Meanwhile, the present invention also provides a low-oxygen-content iron-chromium-aluminum alloy powder, which can be used to prepare low-oxygen-content iron-chromium-aluminum alloy targets, thereby improving the density and other properties of the iron-chromium-aluminum alloy targets.

[0015] Another objective of this invention is to provide a method for preparing iron-chromium-aluminum alloy targets, which can produce chromium-aluminum alloy targets with high density, small and uniform grain size, and no segregation of chromium element distribution.

[0016] Meanwhile, the present invention also provides a chromium-aluminum alloy target material, which has excellent overall quality and good comprehensive performance.

[0017] To achieve the above objectives, the present invention provides a method for preparing iron-chromium-aluminum alloy powder with low oxygen content, comprising the following steps:

[0018] Step 1: Liquid iron, chromium, and aluminum are sequentially subjected to gas-water combined atomization granulation, drying, and sieving to obtain iron powder A, chromium powder A, and aluminum powder A;

[0019] Step 2: Iron powder A, chromium powder A, and aluminum powder A are ball-milled and centrifuged in an inert gas atmosphere to obtain iron powder B, chromium powder B, and aluminum powder B, respectively.

[0020] Step 3: Mix iron powder B, chromium powder B, and aluminum powder B in an inert gas atmosphere to obtain the low oxygen content iron-chromium-aluminum alloy powder;

[0021] In step 1, the gas-water combined atomization granulation uses an inert gas for gas atomization and a mixture of water and a micro-etching agent for water atomization. In step 2, iron powder A, chromium powder A, and aluminum powder A are ball-milled with isopropanol or acetone in an inert gas atmosphere.

[0022] Preferably, the ratio of water to micro-etching agent in the mixed liquid is 10:1-1.5, and the micro-etching agent is sulfuric acid / hydrogen peroxide micro-etching agent.

[0023] Preferably, in the gas-water combined atomization granulation in step 1, the gas pressure for gas atomization is 0.1-1 MPa, and the angle between the gas injection direction and the vertical downward direction is 20-80°; the liquid pressure for water atomization is 30-200 MPa, and the angle between the water injection direction and the vertical downward direction is 20-80°.

[0024] More preferably, in the gas-water combined atomization granulation of step 1, the gas pressure of gas atomization is 0.6-1 MPa, and the angle between the gas injection direction and the vertical downward direction is 40-70°; the liquid pressure of water atomization is 50-150 MPa, and the angle between the water injection direction and the vertical downward direction is 40-70°.

[0025] Further, in step 2, the specific steps of ball milling are as follows: iron powder B, chromium powder B or aluminum powder B and zirconium oxide balls are added to a ball milling jar at a mass ratio of 1:5, inert gas is introduced and isopropanol is added for ball milling, wherein the ball milling speed is 200-500 r / min and the ball milling time is 1-5 h.

[0026] The present invention also discloses a low-oxygen iron-chromium-aluminum alloy powder, which is prepared by the above-mentioned method for preparing low-oxygen iron-chromium-aluminum alloy powder, wherein the mass ratio of iron, chromium and aluminum in the iron-chromium-aluminum alloy powder is 94-97:2-4:1-2.

[0027] This invention also discloses a method for preparing an iron-chromium-aluminum alloy target, comprising the following steps:

[0028] Step a: Add the above-mentioned low-oxygen content iron-chromium-aluminum alloy powder to the binder and knead it under inert gas protection to obtain a uniformly mixed feed.

[0029] Step b: Inject the feedstock to obtain the target preform;

[0030] Step c: The target blank is degreased and sintered sequentially to obtain the iron-chromium-aluminum alloy target material;

[0031] The specific steps of step c are as follows: the target blank is placed in a sintering furnace and heated to 450-600℃ at a heating rate of 2-5℃ / min, and held for 2-6 hours to remove the binder. Then, the temperature is raised to 1380-1530℃ at a heating rate of 1-3℃ / min and held for sintering for 8-24 hours to obtain the iron-chromium-aluminum alloy target material.

[0032] Further, the specific steps of step a are as follows: the low oxygen content iron-chromium-aluminum alloy powder is put into a mixer under inert gas protection and stirred and heated. When the powder is heated to 150-200°C, a binder is added, the mixer head is pressed down, and the mixing is continued for 60-120 minutes at a speed of 10-30 rpm and a mixing temperature of 160-190°C to obtain a uniformly mixed feed.

[0033] Furthermore, the amount of the binder is 5%-20% of the mass of the low-oxygen content iron-chromium-aluminum alloy powder; the binder is composed of 15-30% paraffin wax, 15-25% microcrystalline wax, 20-25% carnauba wax, 15-30% polymer and 1-5% surfactant; the polymer is one or more of polyethylene, polyvinyl alcohol, phthalate, diphthalate, and dimethyl phthalate, and the surfactant is stearic acid, oleic acid, calcium stearate or magnesium stearate.

[0034] Furthermore, the specific steps of step b are as follows: feed material into the injection molding machine, plasticize it with the screw, extrude it into the mold cavity, cool it after filling, and eject the target blank through the ejection mechanism to obtain the target blank; wherein, the injection pressure is 20-50MPa, the injection temperature is 180-220℃, and the cooling time is 5-15s.

[0035] The present invention also discloses an iron-chromium-aluminum alloy target material, which is obtained by mechanical processing after being prepared by the above-mentioned method for preparing iron-chromium-aluminum alloy target material.

[0036] Beneficial effects

[0037] Compared with the prior art, the present invention has at least the following advantages:

[0038] (1) In the process of gas-water combined atomization, the present invention uses a mixed liquid composed of water and micro-etching agent to atomize and break down iron, chromium and aluminum particles. The micro-etching agent can effectively pit and corrode the oxide film on the surface of iron, chromium and aluminum particles, thereby initially destroying the oxide film of iron, chromium and aluminum particles. Combined with ball milling technology, the oxide film on the surface of iron, chromium and aluminum particles is further destroyed comprehensively, thereby significantly reducing the oxygen content of iron, chromium and aluminum particles, preparing iron-chromium-aluminum alloy target material with low oxygen content, and improving the comprehensive performance of iron-chromium-aluminum alloy target material.

[0039] (2) This invention provides a method for preparing iron-chromium-aluminum alloy powder with low oxygen content. By selecting to use a micro-etching agent to perform pitting corrosion on the oxide film on the surface of iron, chromium, and aluminum particles during the gas-water co-atomization process instead of adding a micro-etching agent during the ball milling process to perform comprehensive corrosion on the oxide film on the surface of iron, chromium, and aluminum particles, it can effectively avoid the iron, chromium, and aluminum particles being corroded and the sphericity of iron, chromium, and aluminum particles decreasing due to excessive ball milling. With the technical advantages of preparing iron, chromium, and aluminum particles with good sphericity and small average particle size by gas-water co-atomization, it can also make full use of the technical characteristics of gas-water co-atomization to use a micro-etching agent to corrode the oxide film on the surface of iron, chromium, and aluminum particles, so that the subsequent ball milling process can remove the oxide film on the surface of iron, chromium, and aluminum particles more thoroughly, and completely remove the oxide film, thereby preparing iron-chromium-aluminum alloy powder with low oxygen content.

[0040] (3) This invention uses gas-water combined atomization to prepare iron, chromium and aluminum particles with good sphericity and small average particle size, and uses ball milling to further crush the iron, chromium and aluminum powder, reduce the powder particle size, reduce the powder oxygen content, and improve the sphericity of iron, chromium and aluminum particles, thereby slightly improving the performance of iron-chromium-aluminum alloy target material.

[0041] (4) This invention provides a method for preparing iron-chromium-aluminum alloy targets. The method uses injection molding to prepare targets with high density, high purity and superior performance. Injection molding technology has high requirements for raw material powder. In addition to requiring the particle size to be in the micrometer range and the shape to be close to spherical, it also has high requirements for the particle size distribution and tap density of the powder. Therefore, the low oxygen content iron-chromium-aluminum alloy powder provided by this invention can fully meet the requirements of injection molding technology for raw material powder. Combined with the preparation method of iron-chromium-aluminum alloy targets of this invention, iron-chromium-aluminum alloy targets with superior comprehensive performance can be prepared. Detailed Implementation

[0042] The present invention will be further described below with reference to embodiments, but this does not constitute any limitation on the present invention. Any limited modifications made within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0043] To illustrate the technical content of the present invention in detail, the following description is provided in conjunction with the embodiments.

[0044] It should be noted that since drying and sieving are conventional techniques for powder preparation in this field, the specific processes will not be described in detail.

[0045] In the following embodiments and comparative examples, liquid iron, chromium, and aluminum are obtained by smelting iron, chromium, and aluminum metal raw materials in a smelting furnace. Since smelting metals from solid to liquid is an existing technology, it will not be described in detail here. In addition, drying and screening processes are conventional technical means in the field, and will not be described in detail in the embodiments and comparative examples of the present invention. In the following embodiments and comparative examples, the inert gas is argon.

[0046] Example 1

[0047] A low-oxygen-content iron-chromium-aluminum alloy powder is prepared by the following steps:

[0048] Step 1: Liquid iron is poured into a gas-water combined atomization device for granulation, followed by drying and sieving to obtain iron powder A. In the gas-water combined atomization, the gas used for gas atomization is nitrogen with a pressure of 0.8 MPa and an angle of 40° between the nitrogen injection direction and the vertical downward direction. The liquid used for water atomization is a mixture of water and sulfuric acid / hydrogen peroxide micro-etching agent with a ratio of 10:1. The pressure of the mixed liquid is 120 MPa and the angle of 40° between the mixed liquid injection direction and the vertical downward direction is also 40°. Then, liquid chromium and liquid aluminum are prepared using the same method to obtain chromium powder A and aluminum powder A, respectively.

[0049] Step 2: Add iron powder A and zirconia balls to a ball mill jar at a mass ratio of 1:5, fill with inert gas and add isopropanol to control the solid content to 55%, then ball mill at 300 r / min for 3 hours. Then flush out with isopropanol and put the powder into a centrifuge to separate iron powder B. Using the same method, chromium powder A and aluminum powder A are ball milled and centrifuged in an inert gas atmosphere to obtain chromium powder B and aluminum powder B, respectively.

[0050] Step 3: Mix iron powder B, chromium powder B, and aluminum powder B in a V-type mixer at a mass ratio of 94:4:2 under an inert gas atmosphere to obtain iron-chromium-aluminum alloy powder with low oxygen content.

[0051] Example 2

[0052] A low-oxygen-content iron-chromium-aluminum alloy powder is prepared by the following steps:

[0053] Step 1: Liquid iron is poured into a gas-water combined atomization device for granulation, followed by drying and sieving to obtain iron powder A. In the gas-water combined atomization, the gas used for gas atomization is nitrogen with a pressure of 0.8 MPa and an angle of 40° between the nitrogen injection direction and the vertical downward direction. The liquid used for water atomization is a mixture of water and sulfuric acid / hydrogen peroxide micro-etching agent with a ratio of 10:1. The pressure of the mixed liquid is 120 MPa and the angle of 40° between the mixed liquid injection direction and the vertical downward direction is also 40°. Then, liquid chromium and liquid aluminum are prepared using the same method to obtain chromium powder A and aluminum powder A, respectively.

[0054] Step 2: Add iron powder A and zirconia balls to a ball mill jar at a mass ratio of 1:5, fill with inert gas and add isopropanol to control the solid content to 55%, and ball mill at 300 r / min for 3 hours. Then, flush out the powder with isopropanol and separate the powder in a centrifuge to obtain iron powder B. Using the same method, chromium powder A and aluminum powder A are ball-milled and centrifuged in an inert gas atmosphere to obtain chromium powder B and aluminum powder B, respectively.

[0055] Step 3: Mix iron powder B, chromium powder B, and aluminum powder B in a mass ratio of 94.8:3.6:1.6 in a V-type mixer under an inert gas atmosphere to obtain iron-chromium-aluminum alloy powder with low oxygen content.

[0056] Example 3

[0057] A low-oxygen-content iron-chromium-aluminum alloy powder is prepared by the following steps:

[0058] Step 1: Liquid iron is poured into a gas-water combined atomization device for granulation, followed by drying and sieving to obtain iron powder A. In the gas-water combined atomization, the gas used for gas atomization is nitrogen with a pressure of 0.8 MPa and an angle of 40° between the nitrogen injection direction and the vertical downward direction. The liquid used for water atomization is a mixture of water and sulfuric acid / hydrogen peroxide micro-etching agent with a ratio of 10:1. The pressure of the mixed liquid is 120 MPa and the angle of 40° between the mixed liquid injection direction and the vertical downward direction is also 40°. Then, liquid chromium and liquid aluminum are prepared using the same method to obtain chromium powder A and aluminum powder A, respectively.

[0059] Step 2: Add iron powder A and zirconia balls to a ball mill jar at a mass ratio of 1:5, fill with inert gas and add isopropanol to control the solid content to 55%, and ball mill at 300 r / min for 3 hours. Then, flush out the powder with isopropanol and separate the powder in a centrifuge to obtain iron powder B. Using the same method, chromium powder A and aluminum powder A are ball-milled and centrifuged in an inert gas atmosphere to obtain chromium powder B and aluminum powder B, respectively.

[0060] Step 3: Add iron powder B, chromium powder B, and aluminum powder B to a V-type mixer in an inert gas atmosphere at a mass ratio of 97:2:1 to obtain iron-chromium-aluminum alloy powder with low oxygen content.

[0061] Example 4

[0062] It is largely the same as Example 2, except that in the mixed liquid of gas-water co-atomization in step 1, the ratio of water to sulfuric acid / hydrogen peroxide micro-etching agent is 10:1.5.

[0063] Example 5

[0064] The process is largely the same as in Example 2, except that step 2 is modified as follows: iron powder B and zirconia balls are added to a ball mill jar at a mass ratio of 1:5, inert gas is introduced, and isopropanol is added to control the solid content to 55%. The jar is then ball-milled at 200 r / min for 5 hours. The powder is then flushed out with isopropanol and placed in a centrifuge to separate the powder and obtain iron powder B. Chromium powder A and aluminum powder A are then ball-milled and centrifuged in an inert gas atmosphere using the same method to obtain chromium powder B and aluminum powder B, respectively.

[0065] Comparative Example 1

[0066] It is largely the same as Example 2, except that water is used for water atomization in step 1 of the combined air-water atomization.

[0067] Comparative Example 2

[0068] The process is largely the same as in Example 2, except that step 2 is omitted, and iron powder A, chromium powder A, and aluminum powder A are directly mixed in an inert gas atmosphere to obtain iron-chromium-aluminum alloy powder.

[0069] Comparative Example 3

[0070] The process is largely the same as in Example 2, except that water is used for atomization in step 1 (air-water combined atomization), and step 2 is modified as follows: iron powder B and zirconia balls are added to a ball mill jar at a mass ratio of 1:5, inert gas is introduced, and isopropanol and sulfuric acid / hydrogen peroxide micro-etching agent are added to control the solid content to 55%. The jar is ball-milled at 300 r / min for 3 hours, and then the powder is flushed out with isopropanol and placed in a centrifuge to separate the powder to obtain iron powder B. The ratio of isopropanol to sulfuric acid / hydrogen peroxide micro-etching agent is 10:1. Chromium powder A and aluminum powder A are ball-milled and centrifuged in an inert gas atmosphere to obtain chromium powder B and aluminum powder B, respectively.

[0071] Comparative Example 4

[0072] The process is largely the same as in Example 2, except that step 2 is modified as follows: iron powder B and zirconia balls are added to a ball mill jar at a mass ratio of 1:5, inert gas is introduced, and isopropanol is added to control the solid content to 55%. The jar is then ball-milled at 100 r / min for 5 hours. The powder is then flushed out with isopropanol and placed in a centrifuge to separate the powder and obtain iron powder B. Chromium powder A and aluminum powder A are ball-milled and centrifuged in an inert gas atmosphere using the same method described above to obtain chromium powder B and aluminum powder B, respectively.

[0073] Performance testing

[0074] The iron-chromium-aluminum alloy powders obtained in Examples 1-5 and Comparative Examples 1-4 were tested using an oxygen-nitrogen analyzer to obtain the percentage of oxygen content in the iron-chromium-aluminum alloy powders. The results are shown in Table 1.

[0075] Table 1. Oxygen content detection results of iron-chromium-aluminum alloy powders obtained in Examples 1-5 and Comparative Examples 1-4.

[0076]

[0077]

[0078] According to the results in Table 1:

[0079] According to the data comparison between Example 2 and Comparative Example 1, it can be seen that the present invention uses water and sulfuric acid / hydrogen peroxide micro-etching agent as the mixed liquid for water atomization in gas-water combined atomization, which can effectively reduce the oxygen content in iron-chromium-aluminum alloy powder particles.

[0080] According to the data comparison between Example 2 and Comparative Example 2, it can be seen that simply using sulfuric acid / hydrogen peroxide micro-etching agent to corrode the oxide film on the surface of iron-chromium-aluminum alloy powder particles in gas-water combined atomization cannot effectively reduce the oxygen content of iron-chromium-aluminum alloy powder particles. It is necessary to combine corrosion with ball milling process to completely destroy and remove the oxide film on the surface of iron-chromium-aluminum alloy powder particles in order to effectively reduce the oxygen content in iron-chromium-aluminum alloy powder particles.

[0081] According to the data comparison of Example 2 and Comparative Example 3, it can be seen that the ball milling method using sulfuric acid / hydrogen peroxide micro-etching agent to corrode iron powder, chromium powder, and aluminum powder is more effective than the technical solution of using sulfuric acid / hydrogen peroxide micro-etching agent to corrode iron powder, chromium powder, and aluminum powder in gas-water combined atomization. However, since ball milling itself has already physically damaged iron powder, chromium powder, and aluminum powder, the addition of sulfuric acid / hydrogen peroxide micro-etching agent will lead to more irregular powder morphology due to over-corrosion, resulting in poor subsequent process performance. See Table 2 for details.

[0082] According to the data comparison between Example 2 and Comparative Example 4, the ball milling speed in step 2 has a significant impact on the damage to the oxide film on the surface of the iron-chromium-aluminum alloy powder particles. However, ball milling speeds lower than the range of the present invention can also effectively reduce the oxygen content in the iron-chromium-aluminum alloy powder particles.

[0083] Iron-chromium-aluminum alloy sputtering materials were prepared according to the following steps to obtain application examples 1-5 and application comparative examples 1-4:

[0084] Step a: The low oxygen content iron-chromium-aluminum alloy powder is fed into a mixer under inert gas protection and stirred and heated. When the powder is heated to 180°C, a binder accounting for 7% of the mass of the iron-chromium-aluminum alloy powder is added. The mixer head is pressed down and the mixture is stirred for 120 minutes at a speed of 25 rpm and a mixing temperature of 175°C to obtain a uniformly mixed feed. The binder is composed of 20% paraffin wax, 20% microcrystalline wax, 25% carnauba wax, 30% polyethylene and 5% stearic acid.

[0085] Step b: The feed material is added to the injection molding machine, the screw plasticizes it, and it is extruded into the mold cavity. After filling and cooling, the target blank is ejected through the ejection mechanism to obtain the target blank; wherein, the injection pressure is 45MPa, the injection temperature is 210℃, and the cooling time is 10s.

[0086] Step c: Place the target blank into a sintering furnace, heat it to 450℃ at a heating rate of 2.5℃ / min, hold it at that temperature for 5 hours to remove the binder, and then heat it to 1530℃ at a heating rate of 3℃ / min and hold it at that temperature for 12 hours to obtain the iron-chromium-aluminum alloy target material.

[0087] Performance testing

[0088] The relative density of the target material was measured using the Archimedes displacement method.

[0089] The purity of the target material was determined using inductively coupled plasma technology.

[0090] The overall grain size distribution of the target material can be determined using a metallographic analyzer to determine whether segregation exists in the target material.

[0091] Defects in the target material were detected by ultrasonic non-destructive testing to assess the overall internal quality of the target material.

[0092] The iron-chromium-aluminum alloy targets used in Application Examples 1-5 and Comparative Examples 1-4 were tested according to the above test methods, and the results are shown in Table 2.

[0093] Table 2. Performance test results of iron-chromium-aluminum alloy sputtering materials in Application Examples 1-5 and Comparative Examples 1-4.

[0094] Relative density (%) purity(%) Does it exhibit bias? Internal defects Application Example 1 99.25 99.96 no none Application Example 2 99.36 99.91 no none Application Example 3 99.29 99.94 no none Application Example 4 99.27 99.91 no none Application Example 5 99.32 99.95 no none Application Comparative Example 1 97.65 98.23 Segregation Pores, cracks Application Comparative Example 2 97.59 98.41 Segregation Holes, slag inclusions Application Comparative Example 3 97.62 98.36 Segregation crack Application Comparative Example 4 97.71 98.45 Segregation Holes. Cracks

[0095] According to the results in Table 2:

[0096] The technical solution of the present invention can effectively improve the relative density and purity of iron-chromium-aluminum alloy target material. Furthermore, due to the reduction of oxygen content in the iron-chromium-aluminum alloy powder, the overall grain size distribution of the target material is uniform, there is no segregation phenomenon, the internal oxygen content is low, there are few pores, and there are no obvious internal defects.

[0097] According to the data in Table 1, since the oxygen content of the iron-chromium-aluminum alloy powder prepared in Comparative Example 3 is lower, theoretically the overall performance of the iron-chromium-aluminum alloy target material prepared from it should be better. However, due to the simultaneous use of sulfuric acid / hydrogen peroxide micro-etching agent to corrode the powder particles in the ball milling step, the sphericity of the powder deteriorates, and the particle size uniformity of the powder deteriorates. Therefore, the performance of the prepared iron-chromium-aluminum alloy target material deteriorates.

[0098] The embodiments presented herein are merely selected implementations based on combinations of all possible embodiments. The appended claims should not be limited to the embodiments described herein. Some numerical ranges used in the claims include sub-ranges within them, and variations within these ranges should also be covered by the appended claims.

Claims

1. A method for producing a low-oxygen-content Fe-Cr-Al alloy powder, characterized by, The preparation method comprises the following steps: Step 1: liquid iron, chromium and aluminum are sequentially subjected to gas-water combined atomization granulation, drying and screening to obtain iron powder A, chromium powder A and aluminum powder A; Step 2: the iron powder A, the chromium powder A and the aluminum powder A are sequentially subjected to ball milling and centrifugal separation under an inert gas atmosphere to obtain iron powder B, chromium powder B and aluminum powder B; Step 3: the iron powder B, the chromium powder B and the aluminum powder B are mixed under an inert gas atmosphere to obtain the low-oxygen-content iron-chromium-aluminum alloy powder; In the gas-water combined atomization granulation of step 1, the gas used for gas atomization is an inert gas, and the liquid used for water atomization is a mixed liquid of water and a micro-etching agent; in step 2, the iron powder A, the chromium powder A and the aluminum powder A are added with isopropyl alcohol or acetone for ball milling under an inert gas atmosphere; The mass ratio of iron, chromium and aluminum in the iron-chromium-aluminum alloy powder is 94-97:2-4:1-2; The ratio of water to the micro-etching agent in the mixed liquid is 10:1-1.5, and the micro-etching agent is a micro-etching agent of sulfuric acid and hydrogen peroxide.

2. The method of claim 1, wherein the low-oxygen content ferrochrome-aluminum alloy powder is prepared by the steps of: In the gas-water combined atomization granulation of step 1, the gas pressure for gas atomization is 0.1-1 MPa, and the angle between the gas injection direction and the vertical downward direction is 30-80°; the liquid pressure for water atomization is 30-150 MPa, and the angle between the water injection direction and the vertical downward direction is 30-80°. ​ 3. The method for preparing low-oxygen-content iron-chromium-aluminum alloy powder according to claim 1, characterized in that, In step 2, the specific steps of ball milling are as follows: the iron powder B, the chromium powder B or the aluminum powder B and zirconia balls are added into a ball milling tank at a mass ratio of 1:5, inert gas is filled, isopropyl alcohol is added, and ball milling is performed, wherein the ball milling speed is 200-500 r / min, and the ball milling time is 1-5 h.

4. A low-oxygen content Fe-Cr-Al alloy powder, characterized in that, The low-oxygen-content iron-chromium-aluminum alloy powder is prepared by using the preparation method of any one of claims 1-3.

5. A method of producing an iron-chromium-aluminum alloy target material, characterized by, The preparation method comprises the following steps: Step a: the low-oxygen-content iron-chromium-aluminum alloy powder of claim 4 is added with a binder under inert gas protection for banburying to obtain a uniformly mixed feedstock; Step b: the feedstock is subjected to injection molding to obtain a target blank; Step c: the target blank is sequentially subjected to debinding and sintering to obtain the iron-chromium-aluminum alloy target material; The specific steps of step c are as follows: the target blank is placed into a sintering furnace, heated to 450-600 ℃ at a heating rate of 2-5 ℃ / min, and then heated to 1380-1530 ℃ at a heating rate of 1-3 ℃ / min for 8-24 h of sintering after 2-6 h of debinding to remove the binder, so as to obtain the iron-chromium-aluminum alloy target material.

6. The method of producing an Fe-Cr-Al alloy target according to claim 5, characterized by, The specific steps of step a are as follows: the low-oxygen-content iron-chromium-aluminum alloy powder is put into a banburying machine under inert gas protection for stirring and heating, the binder is added when the powder is heated to 150-200 ℃, the banburying machine pressure head is pressed down, and then stirring is continuously performed at a speed of 10-30 r / min and a mixing temperature of 160-190 ℃ for 60-120 min to obtain a uniformly mixed feedstock.

7. The method of producing an Fe-Cr-Al alloy target according to claim 5, characterized by, The amount of the binder is 5%-20% of the mass of the low-oxygen-content iron-chromium-aluminum alloy powder; the binder is composed of 15-30% paraffin wax, 15-25% microcrystalline wax, 20-25% palm wax, 15-30% macromolecular polymer and 1-5% surfactant; the macromolecular polymer is one or more of polyethylene, polyvinyl alcohol, phthalate, phthalic acid diester and dimethyl phthalate; and the surfactant is stearic acid, oleic acid, calcium stearate or magnesium stearate.

8. The method of producing an Fe-Cr-Al alloy target according to claim 5, characterized by, The specific step b is: feeding the material into an injection molding machine, plasticizing by a screw, extruding into a mold cavity, cooling after filling, ejecting the target blank by an ejecting mechanism, and obtaining the target blank; wherein the injection pressure is 20-50 MPa, the injection temperature is 180-220 DEG C, and the cooling time is 5-15 s.

9. An iron-chromium-aluminum alloy target material, characterized by, The iron-chromium-aluminum alloy target material is obtained by the method of any one of claims 5-8.

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