Chromium-aluminum alloy target material and preparation method thereof

Abstract

The invention discloses a chromium-aluminum alloy target material and a preparation method thereof, and belongs to the technical field of metallurgy. The chromium atom ratio in the target material is larger than 65%, the target material is basically composed of a chromium-aluminum alloy phase, and the area proportion of the alloy phase is larger than 90%. The alloy phase of the target material is an AlCr2 phase, no or only a small amount of elemental Cr phase exists, no elemental Al phase exists, and the area ratio of the elemental Cr phase is 0-10%. Due to a special phase structure, the target material has better strength and extremely high wear resistance and corrosion resistance. According to the preparation method, by adjusting the heating time, the heat preservation time and the cooling time of hot isostatic pressing, it is ensured that an AlCr2 homogeneous body is formed through sufficient reaction, and an AlxCry intermetallic combination phase formed by other peritectic reactions is reduced, so that it is ensured that the prepared target material is basically composed of an AlCr2 alloy phase.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a chromium-aluminum alloy target material and a preparation method thereof. Background Art

[0002] Chromium-aluminum alloy targets are mainly used for coating of semiconductors and integrated circuits, and surface modification of metal cutting tools, molds, and tools. Patent CN202210092184 provides a method for preparing a high-chromium aluminum alloy target, wherein the target is composed of a chromium phase and a chromium-aluminum alloy phase, wherein the area of ​​the chromium phase accounts for 10% to 35%, and the area of ​​the chromium-aluminum alloy phase accounts for 65% to 90%. However, the inventors found that the target prepared by this preparation method has low strength and cannot be used in actual production. Summary of the invention

[0003] The embodiment of the present application provides a chromium-aluminum alloy target material and a preparation method thereof, wherein the chromium atomic ratio in the target material is greater than 65%, and the target material is basically composed of a chromium-aluminum alloy phase, and the area of ​​the alloy phase accounts for more than 90%. The alloy phase of the target material is an AlCr2 phase, with no or only a small amount of a single Cr phase, and no single Al phase, and the area of ​​the single Cr phase accounts for 0 to 10%. Due to the special phase structure, the target material has good strength and extremely high wear resistance and corrosion resistance. The preparation method ensures sufficient reaction to form an AlCr2 homogeneous phase and reduce the Al formed by other peritectic reactions by adjusting the heating, insulation and cooling time of hot isostatic pressing. x Cr y Intermetallic phase, thereby ensuring that the prepared target material is basically composed of AlCr2 alloy phase.

[0004] A first aspect of the present invention provides a method for preparing a chromium-aluminum alloy target, comprising:

[0005] mixing aluminum powder and chromium powder to obtain chromium-aluminum mixed powder;

[0006] The chromium-aluminum powder mixture is placed in a metal package, sealed, and vacuum degassed;

[0007] The degassed metal sheath is subjected to hot isostatic pressing, so that the chromium-aluminum powder mixture forms a chromium-aluminum target blank; wherein the hot isostatic pressing includes a heating process and a cooling process; during the heating process, when the temperature is greater than 600° C., the heating rate is greater than 10° C. / min; during the cooling process, when the temperature is greater than 600° C., the cooling rate is greater than 20° C. / min;

[0008] The chromium-aluminum target rough blank is subjected to a forming operation to obtain a chromium-aluminum alloy target material.

[0009] In some embodiments, the atomic ratio of the chromium powder to the aluminum powder is (65-80):(20-35).

[0010] In some embodiments, the aluminum powder and the chromium powder have a particle size of 1-20 μm.

[0011] In some embodiments, the aluminum powder is in a regular shape, and the chromium powder is in an irregular crushed powder shape.

[0012] In some embodiments, the vacuum degassing temperature is 450-650°C.

[0013] In some embodiments, the vacuum degree of the vacuum degassing is 5×10 -3 Below Pa.

[0014] In some embodiments, the hot isostatic pressing pressure is greater than 100 MPa.

[0015] According to a second aspect of the present invention, a chromium-aluminum alloy target is provided, wherein the chromium atoms in the chromium-aluminum alloy target account for no less than 65%, and the chromium-aluminum alloy target comprises a chromium-aluminum alloy phase, wherein the area of ​​the chromium-aluminum alloy phase accounts for more than 90%.

[0016] In some embodiments, the chromium-aluminum alloy phase is an AlCr2 phase, or the chromium-aluminum alloy phase is an AlCr2 alloy phase and an X alloy phase, wherein the X alloy phase includes a Cr+AlCr2 phase.

[0017] In some embodiments, the chromium-aluminum alloy target further includes a single Cr phase, and the area proportion of the single Cr phase is less than 10%.

[0018] The present invention provides a chromium-aluminum alloy target material and a preparation method thereof, wherein the chromium atomic ratio in the target material is greater than 65%, and the target material is basically composed of a chromium-aluminum alloy phase, and the area of ​​the alloy phase accounts for more than 90%. The alloy phase of the target material is an AlCr2 phase, with no or only a small amount of a single Cr phase, and no single Al phase, and the area of ​​the single Cr phase accounts for 0 to 10%. Due to the special phase structure, the target material has good strength and extremely high wear resistance and corrosion resistance. The preparation method ensures sufficient reaction to form an AlCr2 homogeneous phase and reduce the Al formed by other peritectic reactions by adjusting the heating, insulation and cooling time of hot isostatic pressing. x Cr y Intermetallic phase, thereby ensuring that the prepared target material is basically composed of AlCr2 alloy phase. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A flowchart of a method for preparing a chromium-aluminum alloy target material according to some embodiments is exemplarily shown;

[0020] Figure 2 The metallographic structure morphology of the target material of Example 1 in the exemplary embodiment of the present disclosure is shown;

[0021] Figure 3 The metallographic structure morphology of the target material of Example 2 in the exemplary embodiment of the present disclosure is shown;

[0022] Figure 4 The metallographic structure morphology of the target material of Example 3 in the exemplary embodiment of the present disclosure is shown;

[0023] Figure 5 The metallographic structure morphology of the target material of Comparative Example 1 in the exemplary embodiment of the present disclosure is shown;

[0024] Figure 6 The metallographic structure morphology of the target material of Comparative Example 2 in the exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0025] In order to better understand the above technical solution, the technical solution of the present application is described in detail below through specific implementation methods.

[0026] Chromium-aluminum alloy targets are mainly used for coating of semiconductors and integrated circuits, and surface modification of metal cutting tools, molds, and tools. They form coatings on the surface of materials through vacuum sputtering, evaporation, arc ion plating, and other methods to improve the hardness and friction coefficient of the materials. During the use of the targets, they are generally reacted in a vacuum, nitrogen, or acetylene environment to form a coating. The coating material must have high hardness, good wear resistance, stable chemical properties, no chemical reaction with the workpiece material, heat resistance and oxidation resistance, low friction coefficient, and strong adhesion to the substrate.

[0027] At present, the most widely used target material is chromium-aluminum target material with high aluminum content. This type of target material is a pseudo alloy or semi-alloy. The target material is subjected to arc or sputtering coating methods in a nitrogen atmosphere to react on the material surface to form CrN, AlN and CrAlN films. They are mainly suitable for tool surface coating and decorative plating. They are used to improve cutting efficiency and greatly increase tool life by improving tool surface hardness, thermal stability, and reducing friction coefficient. However, in the coating of semiconductors and integrated circuits, due to certain restrictions, direct vacuum sputtering is generally used, and no other atmosphere is involved in the reaction, so only Al, Cr and Al can be formed. x Cr y coating.

[0028] In addition, the inventors have found through research that the results of relevant thermal corrosion tests show that the oxide film of the Al-Cr coating with a low Cr content is easy to peel off and has poor thermal corrosion resistance, while the surface of the Al-Cr coating with a high Cr content can form a relatively complete oxide film, and the thermal corrosion resistance is significantly better than that of the coating with a low Cr content. Therefore, it is more appropriate to use a chromium-aluminum alloy target with a high chromium content to form an Al-Cr alloy coating in the field of semiconductor and integrated circuit coating, and no other atmosphere is required to participate in the reaction.

[0029] The Al-Cr binary system contains Al7Cr, Al 11 Cr2, Al4Cr, Al9Cr4, Al8Cr5, AlCr2 and X phase. X phase precipitates in the form of metastable phase in supersaturated Cr solid solution and is generally considered to be a stable equilibrium phase of Cr+AlCr2. Studies on the physical phases of chromium-aluminum alloys have shown that most of the physical phases of chromium-aluminum are peritectic or eutectic, and only the alloy phase is AlCr2 phase or Cr+AlCr2 phase, which is a similar homogeneous phase with a relatively consistent body-centered tetragonal structure. This structure can significantly enhance the material's oxidation resistance, corrosion resistance, hardness and other mechanical properties. Studies on Al-Cr coatings have also shown that chromium-aluminum alloy coatings composed of α-Cr phase and AlCr2 phase can significantly improve the oxidation resistance of the base alloy, and are significantly better than Al-infiltrated coatings. The excellent oxidation resistance of chromium-aluminum alloy coatings stems from the appearance of Cr precipitation zones during the oxidation process, which can hinder the diffusion of Al elements in the coating to the substrate to a certain extent, reducing the degradation rate of the coating, while the presence of Cr can promote the selective oxidation of Al and improve the self-healing ability of the coating. Therefore, the alloy phase of high chromium aluminum target should be mainly AlCr2 phase or Cr+AlCr2 phase as the best.

[0030] Invention patent CN202210092184 provides a method for preparing a high-chromium aluminum alloy target, wherein the target is composed of a chromium phase and a chromium-aluminum alloy phase, wherein the area of ​​the chromium phase accounts for 10% to 35%, and the area of ​​the chromium-aluminum alloy phase accounts for 65% to 90%. In fact, the alloy phase of chromium-aluminum is extremely complex, and Cr and Al may be generated in the chromium-aluminum reaction system. x Cr y The intermediate phase can only form AlCr2 phase when the temperature is greater than 910℃, but during the heating and cooling process of hot isostatic pressing, most of the phases undergo a similar peritectic reaction again and form a brittle Al x Cr y Intermetallic compounds. These compounds reduce the strength of the target structure, and are very prone to edge collapse and cracking during processing and use, and are basically unsuitable for actual production. In addition, if the target phase is not limited, the target itself has a multi-phase structure, and the coating formed will also have a multi-phase structure. x Cr y The hardness and corrosion resistance of the mixed phase coating will be greatly reduced compared to the AlCr2 alloy phase coating.

[0031] Based on the above analysis of the inventors, the embodiment of the present application provides a chromium-aluminum alloy target material and a preparation method thereof, in which the chromium atomic ratio in the target material is greater than 65%, and the target material is basically composed of a chromium-aluminum alloy phase, and the area of ​​the alloy phase accounts for more than 90%. The alloy phase of the target material is an AlCr2 phase, with no or only a small amount of Cr phase, and no single Al phase, and the area of ​​the Cr phase accounts for 0 to 10%. Due to the special phase structure, the target material has good strength and extremely high wear resistance and corrosion resistance. The preparation method ensures sufficient reaction to form an AlCr2 homogeneous phase and reduce the Al formed by other peritectic reactions by adjusting the hot isostatic pressing heating, insulation and cooling time. x Cr y Intermetallic phase, thereby ensuring that the prepared target material is basically composed of AlCr2 alloy phase.

[0032] Figure 1 A flow chart of a method for preparing a chromium-aluminum alloy target material according to some embodiments is exemplarily shown. The method includes S100-S400.

[0033] S100, mixing aluminum powder and chromium powder to obtain chromium-aluminum mixed powder.

[0034] In some embodiments, the atomic ratio of the chromium powder to the aluminum powder is (65-80): (20-35). Since the target material has a special AlCr2 phase body-centered tetragonal structure, the target material has good strength and extremely high wear resistance and corrosion resistance. In this embodiment, the raw material chromium powder and aluminum powder are prepared according to the atomic ratio of chromium powder to aluminum powder of (65-80): (20-35) to ensure that the composition conditions of the atomic ratio required to generate AlCr2 phase or Cr+AlCr2 phase are met.

[0035] In some embodiments, the aluminum powder and the chromium powder are mixed by wet ball milling, vacuum dry ball milling, or dry ball milling with inert gas protection. In some embodiments, the mixing time of the aluminum powder and the chromium powder is greater than 1 hour. This ensures that the powders are fully mixed and uniform.

[0036] In some embodiments, the aluminum powder is in a regular shape, and the chromium powder is in an irregular crushed powder shape. The reason for this is that the chromium powder has an irregular surface shape, leaving many sharp corners and pores, so that the specific surface area is large, the surface activity is good, and it is easy to penetrate with the aluminum powder to react to form a chromium-aluminum alloy compound. In addition, since small-particle aluminum powder is very easy to oxidize and adsorb other impurities during preparation and storage, reducing its purity, the shape of the aluminum powder is set to a regular shape, which can avoid the above situation. In some embodiments, the regular shape can be spherical or quasi-spherical, and specifically, a spherical or quasi-spherical powder prepared by atomization and other methods.

[0037] In some embodiments, the particle size of the aluminum powder and the chromium powder is 1-20 μm. In theory, the raw material powder should be a powder with a smaller particle size as much as possible, because the powder with a smaller particle size has a larger specific surface area and a greater surface activity, and the possibility of chemical reaction between the powders in contact with each other is greater and more sufficient, so it is more likely to form AlCr2 phase under certain conditions. In the embodiments of the present application, the particle size and shape of the aluminum powder and the chromium powder are limited to improve the mixing uniformity of the powder and the sufficiency of the chromium-aluminum reaction.

[0038] S200, placing the chromium-aluminum powder mixture into a metal sheath, sealing it, and vacuum degassing it.

[0039] In some embodiments, the temperature of the vacuum degassing is 450-650° C. In some embodiments, the vacuum degree of the vacuum degassing is 5×10 -3 Pa or less. Preferably, the vacuum degree is 5×10 -4 Below Pa.

[0040] In the embodiment of the present application, the chromium-aluminum powder mixture is placed in a prepared metal sheath and welded, and high-temperature degassing is performed through a reserved exhaust pipe. The degassing temperature is 450-650°C, and the final vacuum degree after degassing is 5×10 -3 When the vacuum is below 0.04 Pa, the heating can be stopped and the exhaust pipe can be sealed. A higher vacuum degree can avoid the formation of an oxide layer between powder particles, which is not conducive to the chromium-aluminum interface reaction and easily causes the target material to crack.

[0041] S300, hot isostatic pressing the degassed metal sheath to form a chromium-aluminum target blank from the chromium-aluminum powder mixture; wherein the hot isostatic pressing includes a heating process and a cooling process; during the heating process, when the temperature is greater than 600°C, the heating rate is greater than 10°C / min; during the cooling process, when the temperature is greater than 600°C, the cooling rate is greater than 20°C / min.

[0042] In order to reduce the formation of other uncertain Al x Cr y In contrast, in the hot isostatic pressing described in the embodiments of the present application, when the heating temperature is greater than 600°C, the heating rate is greater than 10°C / min and is as fast as possible, and when the cooling temperature is greater than 600°C, the cooling rate is greater than 20°C / min and is as fast as possible.

[0043] In some embodiments, the temperature of the hot isostatic pressing is 870-1170°C. Preferably, the temperature of the hot isostatic pressing is 910-1100°C. In some embodiments, the pressure of the hot isostatic pressing is greater than 100Mpa. Preferably, the pressure of the hot isostatic pressing is 130-160Mpa. In some embodiments, the heat preservation and pressure holding time of the hot isostatic pressing is 1-8h. Preferably, the heat preservation and pressure holding time of the hot isostatic pressing is 4-6h.

[0044] In the embodiment of the present application, the degassed package can be put into a hot isostatic pressing device for hot isostatic pressing. Considering that chromium and aluminum start to react at 850°C to form Al8Cr5+AlCr2 eutectic, and start to react at 910°C to form AlCr2 homogeneous phase, and the phase reaction at other temperatures is similar to peritectic reaction. Therefore, the process temperature of hot isostatic pressing is set between 870-1170°C, preferably 910-1100°C.

[0045] In the embodiment of the present application, a hot isostatic pressing process is performed to control the formation of chromium and aluminum intermetallic compounds, and a chromium-aluminum alloy target having a full alloy phase (AlCr2, X), or an alloy phase X phase (i.e., Cr+AlCr2 phase) and a small amount of single Cr phase is prepared.

[0046] S400, performing a forming operation on the chromium-aluminum target rough blank to obtain a chromium-aluminum alloy target material.

[0047] In the embodiment of the present application, the target material after hot isostatic pressing can be processed into a chromium-aluminum target material of a desired shape after removing the outer sheath.

[0048] The chromium-aluminum alloy target prepared in the embodiment of the present application has a simple production process and is basically composed of an AlCr2 phase or a Cr+AlCr2 alloy phase with a body-centered tetragonal structure, wherein the alloy phase area accounts for more than 90%, there is no or only a small amount of single Cr phase, and there is no single Al phase, and the Cr phase area accounts for 0-10%. The coating of the chromium-aluminum target with this structure has a good film-forming effect, the film layer is not easy to crack and fall off, the film-base bonding force is strong, and it has extremely high oxidation resistance, corrosion resistance, hardness and other mechanical properties.

[0049] Due to the special phase structure, the target material has good strength and extremely high wear resistance and corrosion resistance. In the preparation method, the embodiment of the present application limits the particle size and morphology of aluminum powder and chromium powder to improve the mixing uniformity of the powder and the sufficiency of the chromium-aluminum reaction. In addition, by adjusting the heating, insulation and cooling time of hot isostatic pressing, it is ensured that the AlCr2 homogeneous phase is fully reacted and the AlCr2 formed by other peritectic reactions is reduced. x Cr y Intermetallic phase, thereby ensuring that the prepared target material is basically composed of AlCr2 alloy phase.

[0050] The embodiment of the present application also provides a chromium-aluminum alloy target material, in which the proportion of chromium atoms in the chromium-aluminum alloy target material is not less than 65%, and the chromium-aluminum alloy target material includes a chromium-aluminum alloy phase, wherein the area proportion of the chromium-aluminum alloy phase is greater than 90%.

[0051] In some embodiments, the chromium-aluminum alloy phase is an AlCr2 phase, or the chromium-aluminum alloy phase is an AlCr2 alloy phase and an X alloy phase, wherein the X alloy phase includes a Cr+AlCr2 phase.

[0052] In some embodiments, the chromium-aluminum alloy target material further includes a single Cr phase, and the area of ​​the single Cr phase accounts for less than 10%. In the embodiment of the present application, the alloy phase of the target material is mainly AlCr2 phase, or AlCr2 alloy phase and X alloy phase, with no or only a small amount of single Cr phase, no single Al phase, and the area of ​​the single Cr phase accounts for 0-10%.

[0053] The present invention provides a chromium-aluminum alloy target material and a preparation method thereof, wherein the chromium atomic ratio in the target material is greater than 65%, and the target material is basically composed of a chromium-aluminum alloy phase, and the area of ​​the alloy phase accounts for more than 90%. The alloy phase of the target material is an AlCr2 phase, with no or only a small amount of Cr phase, and no single Al phase, and the area of ​​the Cr phase accounts for 0 to 10%. Due to the special phase structure, the target material has good strength and extremely high wear resistance and corrosion resistance. The preparation method ensures sufficient reaction to form an AlCr2 homogeneous phase and reduce the Al formed by other peritectic reactions by adjusting the heating, insulation and cooling time of hot isostatic pressing. x Cr y Intermetallic phase, thereby ensuring that the prepared target material is basically composed of AlCr2 alloy phase.

[0054] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Example 1

[0056] Preparation of target material with an atomic ratio of chromium powder to aluminum powder of 67:33.

[0057] Step 1: prepare chromium powder and aluminum powder in corresponding proportions, wherein the chromium powder is irregularly crushed powder with a powder size of ≤20μm, and the aluminum powder is spherical powder with a particle size of ≤20μm. Put the prepared chromium powder and aluminum powder into a ball mill with anhydrous alcohol as a solution, mix for 3 hours, and then dry for use.

[0058] Step 2: Put the dried powder into the low-carbon steel bag, vibrate and pound the outer periphery of the bag to make the powder dense, and weld the end cover and the exhaust pipe. Put the bag into the heating furnace, connect the exhaust pipe to the vacuum unit, and heat up the exhaust. The exhaust temperature is 500℃, and the temperature is maintained until the vacuum degree reaches 5×10 -4 After Pa, flatten the exhaust pipe and seal it.

[0059] Step three, the evacuated package is placed in a hot isostatic pressing equipment for hot isostatic pressing sintering. The hot isostatic pressing temperature is 915°C, the pressure is 150Mpa, and the heat and pressure are maintained for 4 hours. The heating rate is set to 10°C / min when it is greater than 600°C, and the cooling rate is set to 30°C / min.

[0060] Step 4: After hot isostatic pressing, the outer low-carbon steel skin of the package is removed by lathing to obtain a target material, which has high strength and is not easy to crack during processing.

[0061] Through sampling for metallographic analysis and EDS analysis of different color ranges, it is known that the target prepared by this method, such as Figure 2 As shown, it is mainly a combination structure of AlCr2 alloy phase and Cr single phase, in which the Cr single phase (ie, Cr phase) accounts for about 10% (slightly less than 10%).

[0062] Example 2

[0063] Preparation of target material with an atomic ratio of chromium powder to aluminum powder of 75:25.

[0064] Step 1: prepare chromium powder and aluminum powder in corresponding proportions, wherein the chromium powder is irregularly crushed powder with a powder size of ≤20μm, and the aluminum powder is spherical powder with a particle size of ≤20μm. Put the prepared chromium powder and aluminum powder into a ball mill protected by argon gas, mix for 3 hours, and then dry for use.

[0065] Step 2: Put the dried powder into the low-carbon steel bag, vibrate and pound the outer periphery of the bag to make the powder dense, and weld the end cover and the exhaust pipe. Put the bag into the heating furnace, connect the exhaust pipe to the vacuum unit, and heat up the exhaust. The exhaust temperature is 500℃, and the temperature is maintained until the vacuum degree reaches 5×10 -4 After Pa, flatten the exhaust pipe and seal it.

[0066] Step three, the evacuated package is placed in a hot isostatic pressing equipment for hot isostatic pressing sintering. The hot isostatic pressing temperature is 950°C, the pressure is 150Mpa, and the heat and pressure are maintained for 4 hours. The heating rate is set to 10°C / min when it is greater than 600°C, and the cooling rate is set to 30°C / min.

[0067] Step 4: After hot isostatic pressing, the target material sheath is machined to remove the outer low-carbon steel skin to obtain the target material.

[0068] Through sampling for metallographic analysis and EDS analysis of different color ranges, it is known that the target prepared by this method, such as Figure 3 As shown, it is mainly composed of AlCr2, X alloy phase (i.e. Cr+AlCr2 phase) and Cr single phase, among which the single Cr phase area accounts for about 2.5%.

[0069] Example 3

[0070] Preparation of target material with an atomic ratio of chromium powder to aluminum powder of 70:30.

[0071] Step 1: prepare chromium powder and aluminum powder in corresponding proportions, wherein the chromium powder is irregularly crushed powder with a powder size of ≤20μm, and the aluminum powder is spherical powder with a particle size of ≤20μm. Put the prepared chromium powder and aluminum powder into a ball mill protected by argon gas, mix for 3 hours, and then dry for use.

[0072] Step 2: Put the dried powder into the low-carbon steel bag, vibrate and pound the outer periphery of the bag to make the powder dense, and weld the end cover and the exhaust pipe. Put the bag into the heating furnace, connect the exhaust pipe to the vacuum unit, and heat up the exhaust. The exhaust temperature is 500℃, and the temperature is maintained until the vacuum degree reaches 5×10 -4 After Pa, flatten the exhaust pipe and seal it.

[0073] Step three, the evacuated package is placed in a hot isostatic pressing equipment for hot isostatic pressing sintering. The hot isostatic pressing temperature is 1050°C, the pressure is 150Mpa, and the heat and pressure are maintained for 4 hours. The heating rate is set to 10°C / min when it is greater than 600°C, and the cooling rate is set to 30°C / min.

[0074] Step 4: After hot isostatic pressing, the target jacket is machined to remove the outer low-carbon steel skin to obtain the target. By sampling and metallographic analysis and EDS analysis of different color ranges, it is known that the target prepared by this method is Figure 4 As shown, it is mainly composed of AlCr2 phase and X alloy phase (X alloy phase is Cr+AlCr2 phase), and the single Cr phase can basically not be detected.

[0075] Comparative Example 1

[0076] Preparation of a target material with an atomic ratio of chromium powder to aluminum powder of 75:25 (weight ratio of about 85:15).

[0077] Step 1: prepare chromium powder and aluminum powder in corresponding proportions, wherein the chromium powder is irregularly crushed powder with a powder size of ≤20μm, and the aluminum powder is spherical powder with a particle size of ≤20μm. Put the prepared chromium powder and aluminum powder into a ball mill protected by argon gas, mix for 3 hours, and then dry for use.

[0078] Step 2: Put the dried powder into the low-carbon steel bag, vibrate and pound the outer periphery of the bag to make the powder dense, and weld the end cover and the exhaust pipe. Put the bag into the heating furnace, connect the exhaust pipe to the vacuum unit, and heat up the exhaust. The exhaust temperature is 500℃, and the temperature is maintained until the vacuum degree reaches 5×10 -4 After Pa, flatten the exhaust pipe and seal it.

[0079] Step three, the package after degassing is placed in the hot isostatic pressing equipment for hot isostatic pressing sintering. The hot isostatic pressing temperature is 800°C and the pressure is 150Mpa. The temperature and pressure are kept for 4 hours and then cooled naturally.

[0080] Step 4: After hot isostatic pressing, the target material sheath is machined to remove the outer low-carbon steel skin to obtain the target material.

[0081] Through sampling for metallographic analysis and EDS analysis of different color ranges, it is known that the target prepared by this method, such as Figure 5 As shown, the phase may be Al7Cr, Al 11 The target material is composed of Cr2, Al8Cr5 alloy phase and Cr single phase, wherein the single Cr phase accounts for about 25%. Compared with Example 2, the target material has complex phases, poor mechanical processing performance, and is very easy to crack during the sample processing.

[0082] Comparative Example 2

[0083] Preparation of target material with an atomic ratio of chromium powder to aluminum powder of 67:33.

[0084] Step 1: prepare chromium powder and aluminum powder in corresponding proportions, wherein the chromium powder is irregularly crushed powder with a powder particle size of ≤100μm, and the aluminum powder is irregularly crushed powder with a particle size of ≤100μm. Put the prepared chromium powder and aluminum powder into a ball mill protected by argon gas, mix for 3 hours, and then dry for use.

[0085] Step 2: Put the dried powder into the low-carbon steel bag, vibrate and pound the outer periphery of the bag to make the powder dense, and weld the end cover and the exhaust pipe. Put the bag into the heating furnace, connect the exhaust pipe to the vacuum unit, and heat up the exhaust. The exhaust temperature is 500℃, and the temperature is maintained until the vacuum degree reaches 5×10 -4 After Pa, flatten the exhaust pipe and seal it.

[0086] Step three, the evacuated package is placed in a hot isostatic pressing device for hot isostatic pressing sintering. The hot isostatic pressing temperature is 550°C and the pressure is 150 MPa. The temperature and pressure are maintained for 4 hours and then cooled naturally.

[0087] Step 4: After hot isostatic pressing, the target material sheath is machined to remove the outer low-carbon steel skin to obtain the target material.

[0088] Through sampling for metallographic analysis and EDS analysis of different color ranges, it is known that the target prepared by this method, such as Figure 6 As shown, the target material is basically composed of Al and Cr single phases. Compared with Example 2, the target material is a two-phase non-alloy structure.

[0089] In summary, the present invention provides a chromium-aluminum alloy target material and a preparation method thereof, wherein the chromium atomic ratio in the target material is greater than 65%, and the target material is basically composed of a chromium-aluminum alloy phase, and the area of ​​the alloy phase accounts for more than 90%. The alloy phase of the target material is an AlCr2 phase, with no or only a small amount of a single Cr phase, and no single Al phase, and the area of ​​the single Cr phase accounts for 0 to 10%. Due to the special phase structure, the target material has good strength and extremely high wear resistance and corrosion resistance. The preparation method ensures sufficient reaction to form an AlCr2 homogeneous phase and reduce the Al formed by other peritectic reactions by adjusting the heating, insulation and cooling time of hot isostatic pressing. x Cr y Intermetallic phase, thereby ensuring that the prepared target material is basically composed of AlCr2 alloy phase.

[0090] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed. The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application. The above are only preferred implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A method for preparing a chromium-aluminum alloy target, characterized in that: include: mixing aluminum powder and chromium powder to obtain chromium-aluminum mixed powder; The chromium-aluminum powder mixture is placed in a metal package, sealed, and vacuum degassed; The degassed metal sheath is subjected to hot isostatic pressing, so that the chromium-aluminum powder mixture forms a chromium-aluminum target blank; wherein the hot isostatic pressing includes a heating process and a cooling process; during the heating process, when the temperature is greater than 600° C., the heating rate is greater than 10° C. / min; during the cooling process, when the temperature is greater than 600° C., the cooling rate is greater than 20° C. / min; The chromium-aluminum target rough blank is subjected to a forming operation to obtain a chromium-aluminum alloy target material.

2. The method according to claim 1, characterized in that The atomic ratio of the chromium powder to the aluminum powder is (65-80):(20-35).

3. The method according to claim 1, characterized in that The particle size of the aluminum powder and the chromium powder is 1-20 μm.

4. The method according to claim 1, characterized in that: The aluminum powder has a regular shape, and the chromium powder has an irregular crushed powder shape.

5. The method according to claim 1, characterized in that The temperature of the vacuum degassing is 450-650°C.

6. The method according to claim 1, characterized in that The vacuum degree of the vacuum degassing is 5×10 -3 Below Pa.

7. The method according to claim 4, characterized in that The hot isostatic pressing pressure is greater than 100 MPa.

8. A chromium-aluminum alloy target, characterized in that: The chromium atoms in the chromium-aluminum alloy target material account for no less than 65%, and the chromium-aluminum alloy target material includes a chromium-aluminum alloy phase, wherein the chromium-aluminum alloy phase accounts for more than 90% of the area.

9. The chromium-aluminum alloy target according to claim 8, characterized in that: The chromium-aluminum alloy phase is an AlCr2 phase, or the chromium-aluminum alloy phase is an AlCr2 alloy phase + an X alloy phase, wherein the X alloy phase includes Cr + AlCr2 phases.

10. The chromium-aluminum alloy target according to claim 9, characterized in that: The chromium-aluminum alloy target material also includes a single Cr phase, and the area proportion of the single Cr phase is less than 10%.

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