Nickel-tungsten-tantalum alloy target material and preparation method thereof

Abstract

The invention discloses a nickel-tungsten-tantalum alloy target material and a preparation method thereof, and belongs to the technical field of refractory metal materials. Tungsten powder, nickel powder and tantalum powder are mixed, and the nickel-tungsten-tantalum alloy target material is prepared through cold isostatic pressing and vacuum sintering. Tantalum is added on the basis of tungsten and nickel, tantalum can hinder grain growth at a high temperature and can remarkably refine grains, then isostatic cool pressing and vacuum sintering treatment are combined, the density of the prepared nickel-tungsten-tantalum alloy target material is close to theoretical density, the structure is uniform, and the average particle size of a tungsten phase is smaller than 30 micrometers. In addition, the preparation method provided by the invention is simple in process and suitable for batch production.

Description

Technical Field

[0001] The present invention belongs to the technical field of refractory metal materials, and in particular relates to a nickel-tungsten-tantalum alloy target material and a preparation method thereof. Background Art

[0002] Electrochromism is based on the lattice change mechanism of inorganic materials. Under the action of external voltage, electrolyte ions are embedded in the electrochromic layer to cause the lattice structure to change, thereby changing the color of the material. Electrochromic devices have been widely used in life, such as smart glass, anti-glare rearview mirrors, electrochromic displays, etc.

[0003] Tungsten-nickel alloy targets have been promoted and applied as targets for electrochromic glass sputtering coating. The existing patent 201910955313.5 discloses a tungsten-nickel alloy target and its preparation method. The patent uses tungsten powder and nickel powder as raw materials, mixes the two, and then undergoes pressing, sintering heat, isostatic pressing and heat treatment to produce a tungsten-nickel alloy target with a density of more than 99.8% and an average tungsten phase particle size of less than 30 microns. However, the patent requires combining hot isostatic pressing and heat treatment on the basis of sintering to produce a tungsten-nickel alloy target with high density, isotropy and stable performance. The process is complicated and the steps are cumbersome.

[0004] Therefore, there is an urgent need for a method for producing a tungsten-nickel alloy target with a simple process and a density close to the theoretical density, uniform structure, and a small average particle size of the tungsten phase to solve the above problems. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a nickel-tungsten-tantalum alloy target and a preparation method thereof.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The invention provides a method for preparing a nickel-tungsten-tantalum alloy target material, comprising the following steps: mixing tungsten powder, nickel powder and tantalum powder, and preparing the nickel-tungsten-tantalum alloy target material through cold isostatic pressing and vacuum sintering.

[0008] Preferably, in terms of weight percentage, the usage ratio of the tungsten powder, nickel powder and tantalum powder is (37.5-47.5):(37.5-47.5):(5-25).

[0009] Preferably, the mixing time is 5 to 10 hours.

[0010] Preferably, the cold isostatic pressing pressure is 160-240 MPa, and the holding time is 10-30 min.

[0011] Preferably, the vacuum degree of the vacuum sintering is -1 Pa, the temperature of the vacuum sintering is 1370-1420° C., and the insulation time of the vacuum sintering is 1-3 h.

[0012] Preferably, the vacuum sintering process is: heating to 800°C at a rate of 10°C / min, keeping warm for 60 minutes, evacuating to a vacuum degree of -1Pa, and then heating to 1370-1420°C at a rate of 8°C / min, keeping warm for 1-3 hours.

[0013] Preferably, the relative density of the preform obtained by cold isostatic pressing is 50-60%.

[0014] The present invention provides a nickel-tungsten-tantalum alloy target material prepared by the preparation method described in the above technical solution.

[0015] Preferably, the density of the nickel-tungsten-tantalum alloy target is 96.5-98.5%.

[0016] The present invention also provides the use of the nickel-tungsten-tantalum alloy target material described in the above technical solution in the preparation of electrochromic devices.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] The preparation method of the nickel-tungsten-tantalum alloy target provided by the present invention has a simple process and is suitable for mass production. It mainly adopts cold isostatic pressing and vacuum sintering treatment, so that the density of the prepared nickel-tungsten-tantalum alloy target is close to the theoretical density, the structure is uniform, and the average particle size of the tungsten phase is less than 30 microns.

[0019] The method provided by the invention is pollution-free, and no waste materials, waste acids or other pollutants are generated during the preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] Figure 1 This is a fracture morphology of the tungsten-nickel-tantalum target prepared in Example 1;

[0022] Figure 2 The backscattered electron diffraction pattern of the tungsten-nickel-tantalum target prepared in Example 1;

[0023] Figure 3 The fracture morphology of the tungsten-nickel-tantalum target prepared in Example 2;

[0024] Figure 4 The backscattered electron diffraction pattern of the tungsten-nickel-tantalum target prepared in Example 2;

[0025] Figure 5 The fracture morphology of the tungsten-nickel-tantalum target prepared in Example 3;

[0026] Figure 6 The backscattered electron diffraction pattern of the tungsten-nickel-tantalum target prepared in Example 3;

[0027] Figure 7 Surface morphology and energy spectrum analysis of the tungsten-nickel-tantalum target prepared in Comparative Example 1;

[0028] Figure 8 Surface morphology and energy spectrum analysis of the tungsten-nickel-tantalum target prepared in Comparative Example 2;

[0029] Fig. 9 Surface morphology and energy spectrum analysis of the tungsten-nickel-tantalum target prepared in Comparative Example 3. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] An embodiment of the present invention provides a method for preparing a nickel-tungsten-tantalum alloy target, comprising the following steps: mixing tungsten powder, nickel powder and tantalum powder, and preparing the nickel-tungsten-tantalum alloy target by cold isostatic pressing and vacuum sintering.

[0033] The present invention adds tantalum to tungsten and nickel. Tantalum can hinder grain growth at high temperature and significantly refine the grains. Combined with cold isostatic pressing and vacuum sintering, the prepared nickel-tungsten-tantalum alloy target has a density close to the theoretical density, uniform structure, and an average tungsten phase particle size of less than 30 microns. The method is simple in process and suitable for mass production.

[0034] In a preferred embodiment, the ratio of the tungsten powder, nickel powder and tantalum powder is (37.5-47.5):(37.5-47.5):(5-25) by weight. The present invention controls the amount of tantalum powder within the above range. Too little tantalum powder will not significantly refine the grains, and too much tantalum powder will lead to a decrease in the density of the target material.

[0035] In a preferred embodiment, the mixing time is 5 to 10 hours. In the present invention, if the mixing time is too short or too long, uneven mixing will occur, thereby affecting the density of the nickel-tungsten-tantalum alloy target.

[0036] In a preferred embodiment, the mixing device is a Y-type mixer; the mixing speed is 180r / min.

[0037] In a preferred embodiment, the cold isostatic pressing pressure is 160-240 MPa, and the holding time is 10-30 min.

[0038] In a preferred embodiment, the cold isostatic pressing mold comprises a common flexible mold or a tubular flexible mold with a flexible steel core.

[0039] In a preferred embodiment, the vacuum degree of the vacuum sintering is -1Pa, the temperature of the vacuum sintering is 1370-1420°C, and the holding time of the vacuum sintering is 1-3h. If the vacuum sintering temperature in the present invention is too low, the density of the target material will be too low and there will be a large number of pores. If the vacuum sintering temperature is too high, the target material will melt, affecting the quality of the target material.

[0040] In a preferred embodiment, the vacuum sintering process is: heating to 800°C at a rate of 10°C / min, keeping the temperature for 60 minutes, and evacuating to a vacuum degree of -1Pa, and then heating to 1370-1420°C at a rate of 8°C / min, and keeping the temperature for 1-3 hours. The present invention first heats to 800°C and keeps the temperature for a period of time, and then extracts the gas to make the vacuum degree reach -1Pa, so as to avoid the pores shrinking and releasing gas during the sintering process to affect the vacuum degree, thereby causing excessive impurities in the target material and affecting the purity of the target material.

[0041] In a preferred embodiment, the relative density of the preform obtained by cold isostatic pressing is 50-60%, with the reference being the theoretical density of Ni-W-Ta alloy.

[0042] The present invention provides a nickel-tungsten-tantalum alloy target material prepared by the preparation method described in the above technical solution.

[0043] In a preferred embodiment, the density of the nickel-tungsten-tantalum alloy target is 96.5-98.5%.

[0044] The present invention also provides the use of the nickel-tungsten-tantalum alloy target material described in the above technical solution in the preparation of electrochromic devices.

[0045] The room temperature in the embodiments of the present invention refers to "25±2°C".

[0046] Unless otherwise specified, the raw materials in the examples of the present invention were purchased from commercial sources.

[0047] Example 1

[0048] Preparation process of nickel-tungsten-tantalum alloy target:

[0049] a. Tungsten powder with a purity of 99.99%, nickel powder with a purity of 99.99%, and tantalum powder with a purity of 99.99% are loaded into a Y-type mixer at a mass ratio of W:Ni:Ta=2:2:1, and then mixed at a speed of 180r / min for 10h to obtain nickel-tungsten-tantalum alloy powder, in which the mass proportion of W powder is 40%, the mass proportion of Ni powder is 40%, and the mass proportion of Ta powder is 20%.

[0050] b. The tungsten-nickel alloy powder in step a is loaded into a flexible mold, pressurized to 180 MPa for cold isostatic pressing, and maintained at the pressure for 20 minutes to obtain a nickel-tungsten-tantalum blank with a relative density of 52.3%.

[0051] c. The nickel-tungsten-tantalum blank in step b is placed in a vacuum sintering furnace for vacuum sintering at a vacuum degree of -1 Pa, and the temperature is increased to 800°C at a rate of 10°C / min, and kept warm for 60 minutes, and then the temperature is increased to 1400°C at a rate of 8°C / min, and kept warm for 2 hours; the vacuum furnace heating system is turned off and the furnace is cooled to room temperature to obtain a nickel-tungsten-tantalum alloy target with a nickel mass ratio of 40%, a tungsten mass ratio of 40%, and a tantalum mass ratio of 20%, and the target density is 98.5%.

[0052] Figure 1 This is a fracture morphology of the tungsten-nickel-tantalum target prepared in Example 1. Figure 1 It can be seen that the average particle size of the tungsten phase in the tungsten-nickel-tantalum target prepared in Example 1 is 10.2 μm.

[0053] Figure 2 This is the backscattered electron diffraction pattern of the tungsten-nickel-tantalum target prepared in Example 1. Figure 2 It can be seen that the grain boundaries of the tungsten-nickel-tantalum target prepared in Example 1 are obvious.

[0054] Example 2

[0055] Preparation process of nickel-tungsten-tantalum alloy target:

[0056] a. Tungsten powder with a purity of 99.99%, nickel powder with a purity of 99.99%, and tantalum powder with a purity of 99.99% are loaded into a Y-type mixer at a mass ratio of W:Ni:Ta=15:15:10, and then mixed at a speed of 180r / min for 10h to obtain nickel-tungsten-tantalum alloy powder, in which the mass proportion of W powder is 37.5%, the mass proportion of Ni powder is 37.5%, and the mass proportion of Ta powder is 25%.

[0057] b. The tungsten-nickel alloy powder in step a is loaded into a flexible mold, pressurized to 180 MPa for cold isostatic pressing, and maintained at the pressure for 30 minutes to obtain a nickel-tungsten-tantalum blank with a relative density of 53.1%.

[0058] c. The nickel-tungsten-tantalum blank in step b is placed in a vacuum sintering furnace for vacuum sintering at a vacuum degree of -1 Pa, and the temperature is increased to 800°C at a rate of 10°C / min, and kept warm for 60 minutes, and then the temperature is increased to 1400°C at a rate of 8°C / min, and kept warm for 3 hours; the vacuum furnace heating system is turned off and the furnace is cooled to room temperature to obtain a nickel-tungsten-tantalum alloy target with a nickel mass ratio of 37.5%, a tungsten mass ratio of 37.5%, and a tantalum mass ratio of 25%, and the target material density is 96.5%.

[0059] Figure 3 This is the fracture morphology of the tungsten-nickel-tantalum target prepared in Example 2. Figure 3 It can be seen that the average particle size of the tungsten phase in the tungsten-nickel-tantalum target prepared in Example 2 is 10 μm.

[0060] Figure 4 This is the backscattered electron diffraction pattern of the tungsten-nickel-tantalum target prepared in Example 2. Figure 4 It can be seen that the tungsten-nickel-tantalum target prepared in Example 2 has fine grains.

[0061] Example 3

[0062] Preparation process of nickel-tungsten-tantalum alloy target:

[0063] a. Tungsten powder with a purity of 99.99%, nickel powder with a purity of 99.99%, and tantalum powder with a purity of 99.99% are loaded into a Y-type mixer at a mass ratio of W:Ni:Ta=95:95:10, and then mixed at a speed of 180r / min for 10h to obtain nickel-tungsten-tantalum alloy powder, in which the mass proportion of W powder is 47.5%, the mass proportion of Ni powder is 47.5%, and the mass proportion of Ta powder is 5%.

[0064] b. The tungsten-nickel alloy powder in step a is loaded into a flexible mold, pressurized to 180 MPa for cold isostatic pressing, and maintained at the pressure for 10 minutes to obtain a nickel-tungsten-tantalum blank with a relative density of 52.7%.

[0065] c. The nickel-tungsten-tantalum blank in step b is loaded into a vacuum sintering furnace for vacuum sintering at a vacuum degree of -1 Pa, and the temperature is increased to 800°C at a rate of 10°C / min, and kept warm for 60 minutes, and then the temperature is increased to 1400°C at a rate of 8°C / min, and kept warm for 2 hours; the vacuum furnace heating system is turned off and the furnace is cooled to room temperature to obtain a nickel-tungsten-tantalum alloy target with a nickel mass ratio of 47.5%, a tungsten mass ratio of 47.5%, and a tantalum mass ratio of 5%, and the target material density is 97.5%.

[0066] Figure 5 This is the fracture morphology of the tungsten-nickel-tantalum target prepared in Example 3. Figure 5 It can be seen that the average particle size of the tungsten phase in the tungsten-nickel-tantalum target prepared in Example 3 is 12 μm.

[0067] Figure 6 This is the backscattered electron diffraction pattern of the tungsten-nickel-tantalum target prepared in Example 3. Figure 6 It can be seen that compared with Example 1 and Example 2, the grains of the tungsten-nickel-tantalum target prepared in Example 3 grow.

[0068] Comparative Example 1

[0069] Preparation process of nickel-tungsten-tantalum alloy target:

[0070] a. Mix tungsten powder with a purity of 99.99%, nickel powder with a purity of 99.99%, and tantalum powder with a purity of 99.99% in a mass ratio of W:Ni:Ta=2:2:1, and then mix them at a speed of 180r / min for 10h to obtain nickel-tungsten-tantalum alloy powder, in which the mass proportion of W powder is 40%, the mass proportion of Ni is 40%, and the mass proportion of Ta is 20%.

[0071] b. The tungsten-nickel alloy powder in step a is loaded into a flexible mold, pressurized to 180 MPa for cold isostatic pressing, and maintained at the pressure for 20 minutes to obtain a nickel-tungsten-tantalum blank with a relative density of 52.3%.

[0072] c. The nickel-tungsten-tantalum blank in step b is placed in a vacuum sintering furnace for vacuum sintering at a vacuum degree of -1 Pa, and the temperature is increased to 800°C at a rate of 10°C / min, and kept warm for 60 minutes, and then the temperature is increased to 1300°C at a rate of 8°C / min, and kept warm for 2 hours; the vacuum furnace heating system is turned off and the furnace is cooled to room temperature to obtain a nickel-tungsten-tantalum alloy target with a nickel mass ratio of 40%, a tungsten mass ratio of 40%, and a tantalum mass ratio of 20%, and the target material density is 78.6%.

[0073] Figure 7 The surface morphology and energy spectrum analysis of the tungsten-nickel-tantalum target prepared in Comparative Example 1, where a is the target surface SEM, b is the line scan area, c is the line scan result, and d is the elemental analysis. Figure 7 It can be seen that the tungsten-nickel-tantalum target prepared in Comparative Example 1 has many holes on its surface, indicating that its density is low.

[0074] Comparative Example 2

[0075] Preparation process of nickel-tungsten-tantalum alloy target:

[0076] a. Mix tungsten powder with a purity of 99.99%, nickel powder with a purity of 99.99%, and tantalum powder with a purity of 99.99% in a mass ratio of W:Ni:Ta=2:2:1, and then mix them in a Y-type mixer at a speed of 180r / min for 10h to obtain nickel-tungsten-tantalum alloy powder, in which the mass proportion of W powder is 40%, the mass proportion of Ni powder is 40%, and the mass proportion of Ta powder is 20%.

[0077] b. The tungsten-nickel alloy powder in step a is loaded into a flexible mold, pressurized to 180 MPa for cold isostatic pressing, and maintained at the pressure for 20 minutes to obtain a nickel-tungsten-tantalum blank with a relative density of 52.3%.

[0078] c. The nickel-tungsten-tantalum blank in step b is placed in a vacuum sintering furnace for vacuum sintering at a vacuum degree of -1 Pa, and the temperature is increased to 800°C at a rate of 10°C / min, and kept warm for 60 minutes, and then the temperature is increased to 1350°C at a rate of 8°C / min, and kept warm for 2 hours; the vacuum furnace heating system is turned off and the furnace is cooled to room temperature to obtain a nickel-tungsten-tantalum alloy target with a nickel mass ratio of 40%, a tungsten mass ratio of 40%, and a tantalum mass ratio of 20%, and the target material density is 88.7%.

[0079] Figure 8 The surface morphology and energy spectrum analysis of the tungsten-nickel-tantalum target prepared in Comparative Example 2, where a is the target surface SEM, b is the line scan area, c is the line scan result, and d is the elemental analysis. Figure 8 It can be seen that the tungsten-nickel-tantalum target prepared in Comparative Example 2 has more pores on its surface, indicating that its density is low.

[0080] Comparative Example 3

[0081] Preparation process of nickel-tungsten-tantalum alloy target:

[0082] a. Mix tungsten powder with a purity of 99.99%, nickel powder with a purity of 99.99%, and tantalum powder with a purity of 99.99% in a mass ratio of W:Ni:Ta=2:2:1, and then mix them in a Y-type mixer at a speed of 180r / min for 10h to obtain nickel-tungsten-tantalum alloy powder, in which the mass proportion of W powder is 40%, the mass proportion of Ni powder is 40%, and the mass proportion of Ta powder is 20%.

[0083] b. The tungsten-nickel alloy powder in step a is loaded into a flexible mold, pressurized to 180 MPa for cold isostatic pressing, and maintained at the pressure for 20 minutes to obtain a nickel-tungsten-tantalum blank with a relative density of 52.3%.

[0084] c. The nickel-tungsten-tantalum blank in step b is placed in a vacuum sintering furnace for vacuum sintering at a vacuum degree of -1 Pa, and the temperature is increased to 800°C at a rate of 10°C / min, and kept warm for 60 minutes, and then the temperature is increased to 1450°C at a rate of 8°C / min, and kept warm for 2 hours; the vacuum furnace heating system is turned off and the furnace is cooled to room temperature to obtain a nickel-tungsten-tantalum alloy target with a nickel mass ratio of 40%, a tungsten mass ratio of 40%, and a tantalum mass ratio of 20%, and the target material density is 98.7%.

[0085] Fig. 9 The surface morphology and energy spectrum analysis of the tungsten-nickel-tantalum target prepared in Comparative Example 3, where a is the target surface SEM, b is the line scan area, c is the line scan result, and d is the element analysis. Fig. 9 It can be seen that the grains of the tungsten-nickel-tantalum target prepared in Comparative Example 3 grew and spheroidized.

[0086] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for preparing a nickel-tungsten-tantalum alloy target, characterized in that: The following steps are involved: Tungsten powder, nickel powder and tantalum powder are mixed, cold isostatically pressed and vacuum sintered to produce a nickel-tungsten-tantalum alloy target.

2. The method for preparing a nickel-tungsten-tantalum alloy target according to claim 1, characterized in that: In terms of weight percentage, the usage ratio of the tungsten powder, nickel powder and tantalum powder is (37.5-47.5):(37.5-47.5):(5-25).

3. The method for preparing a nickel-tungsten-tantalum alloy target according to claim 1, characterized in that: The mixing time is 5 to 10 hours.

4. The method for preparing a nickel-tungsten-tantalum alloy target according to claim 1, characterized in that: The cold isostatic pressing pressure is 160-240 MPa, and the holding time is 10-30 min.

5. The method for preparing a nickel-tungsten-tantalum alloy target according to claim 1, characterized in that: The vacuum degree of the vacuum sintering is -1 Pa, the temperature of the vacuum sintering is 1370-1420° C., and the insulation time of the vacuum sintering is 1-3 hours.

6. The method for preparing a nickel-tungsten-tantalum alloy target according to claim 1 or 5, characterized in that: The vacuum sintering process is as follows: heating to 800°C at a rate of 10°C / min, keeping the temperature for 60 minutes, evacuating to a vacuum degree of -1Pa, and then heating to 1370-1420°C at a rate of 8°C / min, keeping the temperature for 1-3 hours.

7. The method for preparing a nickel-tungsten-tantalum alloy target according to claim 1, characterized in that: The relative density of the preform obtained by cold isostatic pressing is 50-60%.

8. A nickel-tungsten-tantalum alloy target prepared by the preparation method according to any one of claims 1 to 7.

9. The nickel-tungsten-tantalum alloy target according to claim 8, characterized in that: The density of the nickel-tungsten-tantalum alloy target material is 96.5-98.5%.

10. Use of the nickel-tungsten-tantalum alloy target material according to any one of claims 8 to 9 in the preparation of electrochromic devices.

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