Tantalum-based multilayer composite powder, preparation method thereof and cold spraying coating material

Abstract

The invention provides tantalum-based multilayer composite powder, a preparation method thereof and a cold spraying coating material, and relates to the technical field of metal powder. The tantalum-based multi-layer composite powder comprises Ta powder; a Ta-Mo gradient diffusion layer formed on the surface of the Ta powder; wherein the content of Mo in the Ta-Mo gradient diffusion layer is in gradient distribution from the surface of the Ta powder to the surface of the Ta-Mo gradient diffusion layer; the nanocrystalline Mo layer is formed on the surface of the Ta-Mo gradient diffusion layer; and the MoB2-Mo2N dual-phase nano composite layer is formed on the surface of the nanocrystalline Mo layer. The performance of the tantalum-based material can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of metal powders, and more particularly, to a tantalum-based multi-layer composite powder, a preparation method thereof, and a cold spray coating material. Background Art

[0002] With the continuous improvement of the requirements for material properties in the fields of aerospace, nuclear energy, and extreme environment equipment, tantalum has been widely used in extreme working condition fields due to its excellent corrosion resistance, high-temperature stability, and biocompatibility. However, due to the crystal structure characteristics of tantalum metal itself (the β-phase has low hardness and poor thermal stability at room temperature), the coating directly deposited by the cold spray technology is prone to grain boundary slip caused by residual stress generated by high-speed impact, resulting in the hardness (usually lower than 150 - 200 HV) and wear resistance of the coating being difficult to meet the requirements of extreme environments.

[0003] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0004] The purpose of the present disclosure is to provide a tantalum-based multi-layer composite powder, a preparation method thereof, and a cold spray coating material, so as to at least overcome the problem of insufficient properties of tantalum materials to a certain extent.

[0005] According to a first aspect of the present disclosure, there is provided a tantalum-based multi-layer composite powder, comprising: Ta powder; a Ta-Mo gradient diffusion layer formed on the surface of the Ta powder; wherein, from the surface of the Ta powder to the surface of the Ta-Mo gradient diffusion layer, the content of Mo in the Ta-Mo gradient diffusion layer shows a gradient distribution; a nanocrystalline Mo layer formed on the surface of the Ta-Mo gradient diffusion layer; a MoB2-Mo2N duplex nanocomposite layer formed on the surface of the nanocrystalline Mo layer.

[0006] Optionally, from the surface of the Ta powder to the surface of the Ta-Mo gradient diffusion layer, the content of Mo in the Ta-Mo gradient diffusion layer shows a gradient distribution of 2 at.% to 10 at.%; the thickness of the Ta-Mo gradient diffusion layer is 5 μm to 15 μm.

[0007] Optionally, the content of B in the MoB2-Mo2N duplex nanocomposite layer is 5 at.% to 10 at.%, and the content of N is 8 at.% to 20 at.%.

[0008] According to a second aspect of the present disclosure, there is provided a cold spray coating material prepared using any one of the above tantalum-based multi-layer composite powders.

[0009] According to a third aspect of the present disclosure, a method for preparing a tantalum-based multi-layer composite powder is provided for preparing any of the above tantalum-based multi-layer composite powders. The preparation method includes: performing ball milling on Ta powder and Mo powder to form activated Ta powder containing a Ta-Mo mechanical alloying transition zone; wherein the activated Ta powder is a powder with a Ta-Mo gradient diffusion layer formed on the surface of the Ta powder; performing a staged magnetron sputtering coating process on the activated Ta powder to form a nanocrystalline Mo layer on the surface of the activated Ta powder and a MoB2-Mo2N duplex nanocomposite layer on the surface of the nanocrystalline Mo layer.

[0010] Optionally, performing ball milling on Ta powder and Mo powder to form activated Ta powder containing a Ta-Mo mechanical alloying transition zone includes: placing Ta powder and B4C balls in a vacuum ball milling tank with H2 and Ar atmospheres for a first ball milling process; mixing Mo powder in the vacuum ball milling tank and replacing the B4C balls with ZrO2 balls for a second ball milling process to form activated Ta powder containing a Ta-Mo mechanical alloying transition zone.

[0011] Optionally, the particle size of the B4C balls and ZrO2 balls is 2 mm to 5 mm; the particle size of the Ta powder is 10 μm to 80 μm, and the particle size of the Mo powder is 50 nm to 100 nm; the ball-to-powder ratio of the ZrO2 balls to the Mo powder is 10:1 to 20:1; the gas ratio of H2 to Ar in the H2 and Ar atmospheres is 1:3 to 1:5.

[0012] Optionally, performing a staged magnetron sputtering coating process on the activated Ta powder to form a nanocrystalline Mo layer on the surface of the activated Ta powder and a MoB2-Mo2N duplex nanocomposite layer on the surface of the nanocrystalline Mo layer includes: fixing the Mo target source and the MoB2 target source on the target holder in the vacuum chamber of the magnetron sputtering equipment, evacuating the chamber to a vacuum degree of 5.0×10 -3 Pa to 5.0×10 -4 Pa; putting the activated Ta powder into the chamber, introducing Ar and controlling the vacuum degree to 0.5 Pa to 1.2 Pa, turning on the Mo target source, and controlling the formation of a nanocrystalline Mo layer with a gradient distribution of grain sizes on the surface of the activated Ta powder by dynamically adjusting the Mo target power and the bias voltage; keeping the Mo target source on, turning on the MoB2 target source, introducing a mixed gas of N2 and Ar and controlling the vacuum degree to 0.7 Pa to 1.5 Pa to form a MoB2-Mo2N duplex nanocomposite layer on the surface of the nanocrystalline Mo layer.

[0013] Optionally, when the Mo target source is turned on, the arc target power of the Mo target source is 50 W to 150 W, the negative bias voltage of the bias power supply is -50 V to -150 V, the duty cycle is 40% to 60%, and the deposition time is 20 min to 60 min.

[0014] Optionally, when the MoB2 target source is turned on, the arc target power of the MoB2 target source is 70 W to 120 W, the negative bias voltage and duty cycle of the bias power supply remain unchanged, the deposition time is 10 min to 30 min; the gas ratio of N2 to Ar in the mixed gas of N2 and Ar is 1:3 to 1:6.

[0015] In the solution of the exemplary embodiment of the present disclosure, based on the multi-layer composite design, the controllable preparation of high-performance tantalum powder can be achieved by strengthening the interface bonding and microstructure regulation. A dense transition zone can be formed by optimizing the Ta / Mo atomic ratio to inhibit crack propagation. The formation of the middle-layer nanocrystalline Mo layer can texture-dominated crystal orientations to improve the deformation resistance. In addition, the top-layer MoB2 / Mo2N duplex nanocomposite layer forms a superhard phase through boron-nitrogen co-doping, greatly expanding its application scope as a coating material.

[0016] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can obtain other drawings without creative efforts based on these drawings.

[0018] Figure 1 Schematically shows a structural diagram of a tantalum-based multi-layer composite powder according to an exemplary embodiment of the present disclosure.

[0019] Figure 2 Schematically shows a flowchart of a method for preparing a tantalum-based multi-layer composite powder according to an exemplary embodiment of the present disclosure.

[0020] Figure 3 Schematically shows an SEM (Scanning Electron Microscope) image of Ta powder after the first ball milling process in Example 1 of the present disclosure.

[0021] Figure 4 Schematically shows an SEM image of the formation of a nanocrystalline Mo layer in Example 1 of the present disclosure.

[0022] Figure 5 Schematically shows in Example 1 of the present disclosure Figure 4 The corresponding Ta and Mo content schematic diagram.

[0023] Figure 6 Schematically shows an SEM image of the tantalum-based multi-layer composite powder in Example 1 of the present disclosure. Detailed Implementation Modes

[0024] Example implementation modes will now be described more fully with reference to the accompanying drawings. However, the example implementation modes can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these implementation modes are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example implementation modes to those skilled in the art. The features, structures, or characteristics described may be combined in any suitable manner in one or more implementation modes. In the following description, numerous specific details are provided to give a thorough understanding of the implementation modes of this disclosure. However, those skilled in the art will realize that one or more of the specific details may be omitted in practicing the technical solutions of this disclosure, or other methods, processes, steps, etc. may be adopted. In other cases, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0025] In addition, the accompanying drawings are only schematic illustrations of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus repeated descriptions thereof will be omitted. The flowcharts shown in the drawings are only exemplary illustrations and do not necessarily include all steps. For example, some steps can be decomposed, while some steps can be combined or partially combined, so the actual execution order may change according to the actual situation. Additionally, all the following terms "first", "second", etc. are for the purpose of distinction only and should not be construed as limitations on the content of this disclosure.

[0026] For tantalum (Ta) metal powder, its performance can be improved by alloying modification (such as adding molybdenum, tungsten, etc.). However, there are significant differences in the physical and chemical properties between Ta and these metals, and an extremely long ball milling time (e.g., greater than 50 h) is required to achieve partial alloying, and the severe mechanical action will cause a sharp increase in the oxygen content of the powder, seriously deteriorating the material performance. Additionally, various metals and their alloys can be prepared on the surface of Ta powder through physical vapor deposition technology. However, Ta powder mostly has an irregular porous structure, and conventional physical vapor deposition technology is difficult to achieve nanoscale uniform coating on complex surfaces, resulting in poor performance of the final coated powder.

[0027] To improve the performance of Ta metal powder, an embodiment of this disclosure provides a new tantalum-based multi-layer composite powder. This tantalum-based multi-layer composite powder is prepared through a synergistic process of gradient ball milling and magnetron sputtering, and a Ta-Mo gradient diffusion layer, a nanocrystalline Mo layer, and a MoB2-Mo2N duplex nanocomposite layer are sequentially formed on the surface of Ta powder.

[0028] Figure 1 A schematic diagram of the structure of the tantalum-based multi-layer composite powder according to an exemplary implementation mode of this disclosure is schematically shown. Refer to Figure 1, the tantalum-based multi-layer composite powder of the exemplary embodiment of the present disclosure includes Ta powder 11, a Ta-Mo gradient diffusion layer 12 formed on the surface of Ta powder 11, a nanocrystalline Mo layer 13 formed on the surface of Ta-Mo gradient diffusion layer 12, and a MoB2-Mo2N duplex nanocomposite layer 14 formed on the surface of nanocrystalline Mo layer 13.

[0029] In the exemplary embodiment of the present disclosure, the shape of Ta powder 11 can be any one of spherical, flaky, cubic, fibrous, and irregular blocky shapes, and the particle size of Ta powder 11 is 10 μm to 80 μm.

[0030] The Ta-Mo gradient diffusion layer 12 is formed by gradient ball milling technology, synchronously realizing oxide removal and mechanical alloying, and reducing the interfacial energy barrier.

[0031] From the surface of Ta powder 11 to the surface of Ta-Mo gradient diffusion layer 12, the content of Mo in Ta-Mo gradient diffusion layer 12 shows a gradient distribution. Specifically, in the direction from Ta powder 11 to Ta-Mo gradient diffusion layer 12, the content of Mo shows a gradient distribution of 2 at.% to 10 at.%. Specifically, the thickness of Ta-Mo gradient diffusion layer 12 is 5 μm to 15 μm.

[0032] The nanocrystalline Mo layer 13 and the MoB2-Mo2N duplex nanocomposite layer 14 are realized by magnetron sputtering process, specifically realizing stepped transition and nanocrystalline oriented growth, and simultaneously endowing the material with high-temperature oxidation resistance, corrosion resistance, and superhard wear resistance.

[0033] The purity of the nanocrystalline Mo layer 13 is not less than 99%, the content of B in the MoB2-Mo2N duplex nanocomposite layer 14 is 5 at.% to 10 at.%, and the content of N is 8 at.% to 20 at.%. Through reasonable optimization design of the element composition, this ratio of Mo, B, and N can improve the hardness and wear resistance of the powder, and simultaneously ensure the corrosion resistance of the powder.

[0034] Furthermore, the embodiment of the present disclosure also provides a cold spray coating material, which can be prepared based on the above tantalum-based multi-layer composite powder.

[0035] Furthermore, the embodiment of the present disclosure also provides a preparation method of the tantalum-based multi-layer composite powder, and this preparation method is used to prepare the above tantalum-based multi-layer composite powder.

[0036] Figure 2 Schematically shows a flowchart of the preparation method of the tantalum-based multi-layer composite powder of the exemplary embodiment of the present disclosure. Refer to Figure 2 , this preparation method includes the following steps: S22. Ball mill Ta powder and Mo powder to form activated Ta powder containing a Ta-Mo mechanically alloyed transition zone.

[0037] Among them, the activated Ta powder is a powder with a Ta-Mo gradient diffusion layer formed on the surface of the Ta powder.

[0038] According to some embodiments of the present disclosure, first, place Ta powder and B4C balls in a vacuum ball mill tank with an atmosphere of H2 and Ar for the first ball milling process. Next, mix Mo powder in the vacuum ball mill tank and replace the B4C balls with ZrO2 balls for the second ball milling process to form activated Ta powder containing a Ta-Mo mechanically alloyed transition zone.

[0039] Specifically, the particle sizes of the B4C balls and ZrO2 balls are 2 mm to 5 mm, the particle size of the Ta powder is 10 μm to 80 μm, the particle size of the Mo powder is 50 nm to 100 nm, the ball-to-material ratio of the ZrO2 balls to the Mo powder is 10:1 to 20:1, and the gas ratio of H2 to Ar in the H2 and Ar atmosphere is 1:3 to 1:5. In addition, the ball milling rate is controlled at 200 rpm to 500 rpm, and the ball milling time is 2 h to 5 h.

[0040] S24. Perform a staged magnetron sputtering coating process on the activated Ta powder to form a nanocrystalline Mo layer on the surface of the activated Ta powder and a MoB2-Mo2N duplex nanocomposite layer on the surface of the nanocrystalline Mo layer.

[0041] First, fix the Mo target source and the MoB2 target source on the target seats in the vacuum chamber of the magnetron sputtering equipment, evacuate the chamber to a vacuum degree of 5.0×10 -3 Pa to 5.0×10 -4 Pa, and set the deposition temperature of the magnetron sputtering to 250 °C to 400 °C.

[0042] Then, put the activated Ta powder into the chamber, introduce Ar and control the vacuum degree to 0.5 Pa to 1.2 Pa, turn on the Mo target source, and control the formation of a nanocrystalline Mo layer with a gradient distribution of grain sizes on the surface of the activated Ta powder by dynamically adjusting the Mo target power and the bias voltage. Specifically, when the Mo target source is turned on, the arc target power of the Mo target source is 50 W to 150 W, the negative bias voltage of the bias power supply is -50 V to -150 V, the duty cycle is 40% to 60%, and the deposition time is 20 min to 60 min.

[0043] Subsequently, keep the Mo target source on, turn on the MoB2 target source, introduce a mixed gas of N2 and Ar, and control the vacuum degree to be 0.7 Pa to 1.5 Pa to form a MoB2-Mo2N duplex nanocomposite layer on the surface of the nanocrystalline Mo layer. Specifically, keep the conditions such as the arc target power, negative bias voltage, and duty cycle of the Mo target source unchanged. When the MoB2 target source is turned on, the arc target power of the MoB2 target source is 70 W to 120 W, the negative bias voltage and duty cycle of the bias power supply remain unchanged, the deposition time is 10 min to 30 min, and the gas ratio of N2 to Ar in the mixed gas of N2 and Ar is 1:3 to 1:6.

[0044] In the solution of the exemplary embodiment of the present disclosure, based on the design of multi-layer composite, the controllable preparation of high-performance tantalum powder can be realized by strengthening interface bonding and microstructure regulation. A dense transition zone can be formed by optimizing the Ta / Mo atomic ratio to inhibit crack propagation. The middle nanocrystalline Mo layer is dominated by the (110) texture crystal orientation to improve the anti-deformation ability. In addition, the top MoB2-Mo2N duplex nanocomposite layer forms a superhard phase through boron and nitrogen co-doping, greatly expanding its application scope as a coating material.

[0045] In addition, through modular design, the present disclosure can flexibly regulate ball milling media (such as Mo / ZrO2, W / Cr2O3, etc.) and magnetron sputtering technology (such as Mo, W, Re, etc.), and then realize the large-scale production of various composite powders such as Ta@Mo, Ta@W, Ta@Re, etc. The present disclosure does not limit this.

[0046] The preparation process of the tantalum-based multi-layer composite powder of the embodiment of the present disclosure will be described below through examples.

[0047] Example 1 First step, place irregular Ta powder and gradient ball milling media in a vacuum ball milling tank, introduce a mixed gas of H2:Ar = 1:3, and coarsely mill with B4C balls for 4 h at a rotation speed of 200 rpm. Among them, this coarse milling process corresponds to the above-mentioned first ball milling process. Figure 3 The SEM image of Ta powder after this process is shown.

[0048] Second step, mix in Mo powder, replace the B4C balls with ZrO2 balls, the ball-to-material ratio is 20:1, the mixed gas ratio remains unchanged, ball mill for 2 h at a rotation speed of 500 rpm to form activated Ta powder containing a Ta-Mo mechanical alloying transition zone.

[0049] Third step, fix the Mo target source and the MoB2 target source on the target seat in the vacuum chamber of the magnetron sputtering equipment, evacuate the chamber until 5.0×10 -3 Pa, and the deposition temperature is 250 °C.

[0050] Step 4: Place the activated Ta powder into the chamber, introduce Ar into the vacuum chamber and maintain the vacuum degree at 0.5 Pa. Then turn on the Mo target source. During the deposition process, the arc target power of the Mo target source is gradually reduced from 100 W to 50 W, the negative bias voltage of the bias power supply is increased from -50 V to -100 V, the duty cycle is 40%, and the deposition time is 20 min. A nanocrystalline Mo layer is deposited on the surface of the tantalum powder.

[0051] Figure 4 Schematically shows the SEM image of the formation of the nanocrystalline Mo layer in Example 1 of the present disclosure. Figure 5 Schematically shows the schematic diagram of the corresponding Ta and Mo contents.

[0052] Step 5: Keep the conditions such as the arc target power of the Mo target, the negative bias voltage, and the duty cycle unchanged. Introduce a mixed gas of N2 and Ar into the vacuum chamber. The ratio of the introduced N2 and Ar mixed gas is 1:3. Adjust the gas flow rate to maintain the vacuum degree at 0.7 Pa. Turn on the MoB2 target source, set the arc target power to 70 W, and the deposition time is 10 min. Figure 6 Schematically shows the SEM image of the tantalum-based multi-layer composite powder in Example 1 of the present disclosure.

[0053] Example 2 Step 1: Place the spherical Ta powder and the gradient ball milling medium into the vacuum ball milling tank, introduce a mixed gas of H2:Ar = 1:4, and perform rough milling with B4C balls for 3 h at a rotation speed of 300 rpm. Among them, this rough milling process corresponds to the above first ball milling process.

[0054] Step 2: Mix in Mo powder, replace the B4C balls with ZrO2 balls, the ball-to-material ratio is 10:1, the proportion of the mixed gas remains unchanged, ball mill for 3 h, and set the rotation speed to 400 rpm to form activated Ta powder containing a Ta-Mo mechanically alloyed transition zone.

[0055] Step 3: Fix the Mo target source and the MoB2 target source on the target seat in the vacuum chamber of the magnetron sputtering equipment, evacuate the chamber until 5.0×10 -4 Pa, and the deposition temperature is 300 °C.

[0056] Step 4: Place the activated Ta powder into the chamber, introduce Ar into the vacuum chamber and maintain the vacuum degree at 0.8 Pa. Then turn on the Mo target source. During the deposition process, the arc target power of the Mo target source is gradually reduced from 150 W to 50 W, the negative bias voltage of the bias power supply is increased from -100 V to -150 V, the duty cycle is 40%, and the deposition time is 30 min. A nanocrystalline Mo layer is deposited on the surface of the tantalum powder.

[0057] Step 5: Keep conditions such as the arc target power of the Mo target, negative bias voltage, and duty cycle unchanged. Introduce a mixed gas of N2 and Ar into the vacuum chamber. The ratio of the introduced N2 to Ar mixed gas is 1:4. Adjust the gas flow rate to maintain a vacuum degree of 1.0 Pa. Turn on the MoB2 target source, set the arc target power to 90 W, and the deposition time to 20 min.

[0058] Example 3 Step 1: Place irregular Ta powder and gradient ball-milling media in a vacuum ball-milling tank. Introduce a mixed gas of H2:Ar = 1:5, and coarsely mill with B4C balls for 2 h at a rotation speed of 200 rpm. Among them, this coarse milling process corresponds to the above-mentioned first ball-milling process.

[0059] Step 2: Mix in Mo powder, replace the B4C balls with ZrO2 balls, with a ball-to-material ratio of 15:1, keep the mixed gas ratio unchanged, ball-mill for 4 h at a rotation speed of 400 rpm to form activated Ta powder with a Ta-Mo mechanically alloyed transition zone.

[0060] Step 3: Fix the Mo target source and MoB2 target source on the target seat in the vacuum chamber of the magnetron sputtering equipment. Evacuate the chamber until 2.0×10 -3 Pa, and the deposition temperature is 350 °C.

[0061] Step 4: Put the activated Ta powder into the chamber. Introduce Ar into the vacuum chamber and maintain the vacuum degree at 1.0 Pa. Then turn on the Mo target source. During the deposition process, the arc target power of the Mo target source gradually decreases from 150 W to 50 W, the negative bias voltage of the bias power supply increases from -50 V to -150 V, the duty cycle is 40%, and the deposition time is 40 min to deposit a nanocrystalline Mo layer on the surface of the tantalum powder.

[0062] Step 5: Keep conditions such as the arc target power of the Mo target, negative bias voltage, and duty cycle unchanged. Introduce a mixed gas of N2 and Ar into the vacuum chamber. The ratio of the introduced N2 to Ar mixed gas is 1:5. Adjust the gas flow rate to maintain a vacuum degree of 1.2 Pa. Turn on the MoB2 target source, set the arc target power to 120 W, and the deposition time to 30 min.

[0063] Example 4 Step 1: Place irregular Ta powder and gradient ball-milling media in a vacuum ball-milling tank. Introduce a mixed gas of H2:Ar = 1:4, and coarsely mill with B4C balls for 2 h at a rotation speed of 500 rpm. Among them, this coarse milling process corresponds to the above-mentioned first ball-milling process.

[0064] Step 2: Mix in Mo powder, replace the B4C balls with ZrO2 balls, with a ball-to-material ratio of 10:1, keep the mixed gas ratio unchanged, ball-mill for 2 h at a rotation speed of 200 rpm to form activated Ta powder with a Ta-Mo mechanically alloyed transition zone.

[0065] Step 3: Fix the Mo target source and MoB₂ target source on the target seats in the vacuum chamber of the magnetron sputtering equipment, evacuate the chamber until it reaches 5.0×10 -3 Pa, and the deposition temperature is 400 °C.

[0066] Step 4: Put the activated Ta powder into the chamber, introduce Ar into the vacuum chamber and maintain the vacuum degree at 1.0 Pa, then turn on the Mo target source. During the deposition process, the arc target power of the Mo target source gradually decreases from 150 W to 100 W, the negative bias voltage of the bias power supply increases from -100 V to -150 V, the duty cycle is 40%, and the deposition time is 60 min. A nanocrystalline Mo layer is deposited on the surface of the tantalum powder.

[0067] Step 5: Keep the conditions such as the arc target power of the Mo target, the negative bias voltage, and the duty cycle unchanged, introduce a mixed gas of N₂ and Ar into the vacuum chamber, the ratio of the introduced N₂ and Ar mixed gas is 1:6, adjust the gas flow rate to maintain the vacuum degree at 1.5 Pa, turn on the MoB₂ target source, set the arc target power to 100 W, and the deposition time is 20 min.

[0068] It should be noted that although the steps of the method in the present disclosure are described in a specific order in the drawings, this does not require or imply that these steps must be executed in that specific order, or that all the steps shown must be executed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution, etc.

[0069] In addition, the above-mentioned drawings are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present disclosure, rather than for limiting purposes. It is easy to understand that the processes shown in the above-mentioned drawings do not indicate or limit the chronological order of these processes. Additionally, it is also easy to understand that these processes may be executed synchronously or asynchronously in, for example, multiple modules.

[0070] Those skilled in the art will readily think of other embodiments of the present disclosure after considering the specification and practicing the content disclosed herein. This application aims to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include the common general knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the claims.

[0071] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A tantalum-based multi-layer composite powder, characterized in that, Comprising: Ta powder; A Ta-Mo gradient diffusion layer formed on the surface of the Ta powder; wherein, from the surface of the Ta powder to the surface of the Ta-Mo gradient diffusion layer, the content of Mo in the Ta-Mo gradient diffusion layer shows a gradient distribution; A nanocrystalline Mo layer formed on the surface of the Ta-Mo gradient diffusion layer; A MoB2-Mo2N duplex nanocomposite layer formed on the surface of the nanocrystalline Mo layer.

2. The tantalum-based multilayer composite powder according to claim 1, wherein From the surface of the Ta powder to the surface of the Ta-Mo gradient diffusion layer, the content of Mo in the Ta-Mo gradient diffusion layer shows a gradient distribution of 2 at.% to 10 at.%; The thickness of the Ta-Mo gradient diffusion layer is 5 μm to 15 μm.

3. The tantalum-based multi-layer composite powder according to claim 1, characterized in that, In the MoB2-Mo2N duplex nanocomposite layer, the content of B is 5 at.% to 10 at.%, and the content of N is 8 at.% to 20 at.%.

4. A cold spray coating material prepared from the tantalum-based multilayer composite powder according to any one of claims 1 to 3.

5. A method for preparing a tantalum-based multi-layer composite powder, characterized in that, The preparation method is used to prepare the tantalum-based multilayer composite powder according to any one of claims 1 to 3, and the preparation method includes: Performing ball milling on Ta powder and Mo powder to form activated Ta powder containing a Ta-Mo mechanical alloying transition zone; wherein, the activated Ta powder is the powder with a Ta-Mo gradient diffusion layer formed on the surface of the Ta powder; Performing a staged magnetron sputtering coating process on the activated Ta powder to form a nanocrystalline Mo layer on the surface of the activated Ta powder and a MoB2-Mo2N duplex nanocomposite layer on the surface of the nanocrystalline Mo layer.

6. The preparation method according to claim 5, characterized in that, Performing ball milling on Ta powder and Mo powder to form activated Ta powder containing a Ta-Mo mechanical alloying transition zone, including: Placing Ta powder and B4C balls in a vacuum ball milling tank with H2 and Ar atmospheres for a first ball milling process; Mixing Mo powder in the vacuum ball milling tank and replacing the B4C balls with ZrO2 balls for a second ball milling process to form activated Ta powder containing a Ta-Mo mechanical alloying transition zone.

7. The preparation method according to claim 6, wherein The particle sizes of the B4C balls and ZrO2 balls are 2 mm to 5 mm; The particle size of the Ta powder is 10 μm to 80 μm, and the particle size of the Mo powder is 50 nm to 100 nm; The ball-to-powder ratio of the ZrO2 balls to the Mo powder is 10:1 to 20:1; In the H2 and Ar atmospheres, the gas ratio of H2 to Ar is 1:3 to 1:

5.

8. The preparation method according to claim 5, characterized in that, Performing a staged magnetron sputtering coating process on the activated Ta powder to form a nanocrystalline Mo layer on the surface of the activated Ta powder and a MoB2-Mo2N duplex nanocomposite layer on the surface of the nanocrystalline Mo layer, including: Fix the Mo target source and the MoB2 target source on the target holder in the vacuum chamber of the magnetron sputtering equipment, and evacuate the chamber to a vacuum degree of 5.0×10 -3 Pa to 5.0×10 -4 Pa; Putting the activated Ta powder into a chamber, introducing Ar and controlling the vacuum degree to be 0.5 Pa to 1.2 Pa, turning on the Mo target source, and controlling the formation of a nanocrystalline Mo layer with a gradient distribution of grain sizes on the surface of the activated Ta powder by dynamically adjusting the Mo target power and bias voltage; Keep the Mo target source on, turn on the MoB2 target source, introduce a mixed gas of N2 and Ar and control the vacuum degree to be 0.7 Pa to 1.5 Pa to form a MoB2-Mo2N duplex nano-composite layer on the surface of the nanocrystalline Mo layer.

9. The preparation method according to claim 8, characterized in that, When the Mo target source is turned on, the arc target power of the Mo target source is 50 W to 150 W, the negative bias voltage of the bias power supply is -50 V to -150 V, the duty cycle is 40% to 60%, and the deposition time is 20 min to 60 min.

10. The preparation method according to claim 8, characterized in that, When the MoB2 target source is turned on, the arc target power of the MoB2 target source is 70 W to 120 W, the negative bias voltage and the duty cycle of the bias power supply remain unchanged, and the deposition time is 10 min to 30 min; In the mixed gas of N2 and Ar, the gas ratio of N2 to Ar is 1:3 to 1:6.

Images