Tungsten alloy electrode material and preparation method thereof

Abstract

The invention belongs to the technical field of tungsten alloy, and particularly discloses a tungsten alloy electrode material and a preparation method thereof.The tungsten alloy electrode material comprises, by weight, 0.1%-0.2% of lanthanum boride, 0.2%-0.5% of zirconium oxide, 0.2%-0.6% of boron carbide, 0.4%-0.8% of cerium oxide, 0.5%-1.2% of tantalum carbide, 1.4%-1.8% of modified carbon nanotubes and the balance tungsten powder. The lanthanum boride, the zirconium oxide, the boron carbide, the cerium oxide, the tantalum carbide and the modified carbon nanotubes are added into the tungsten powder, under the combined action of the lanthanum boride, the zirconium oxide, the boron carbide, the cerium oxide, the tantalum carbide and the modified carbon nanotubes, the tensile strength and the electrical conductivity are effectively improved, and the high-temperature stability tungsten powder has excellent high-temperature stability and wide application prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tungsten alloy, in particular to a tungsten alloy electrode material and a preparation method thereof. BACKGROUND

[0002] The tungsten alloy is widely used in the fields of electronics and electricity, especially as electrode material in welding and arc discharge technology, due to its high melting point, high specific gravity, high electrical conductivity, good high-temperature resistance and corrosion resistance.

[0003] The conventional tungsten alloy electrode material is prone to ablation, oxidation or failure under high-temperature and high-pressure conditions, resulting in shortened electrode life and reduced work efficiency.

[0004] In view of this, the present application is proposed. SUMMARY

[0005] The present application provides a tungsten alloy electrode material and a preparation method thereof, wherein the tungsten alloy electrode material has excellent tensile strength and electrical conductivity, and excellent high-temperature stability.

[0006] The present application solves the technical problem by adopting the following technical solution: The tungsten alloy electrode material comprises the following preparation raw materials by weight percentage: 0.1-0.2% lanthanum boride, 0.2-0.5% zirconium oxide, 0.2-0.6% boron carbide, 0.4-0.8% cerium oxide, 0.5-1.2% tantalum carbide, 1.4-1.8% modified carbon nanotubes, and the balance of tungsten powder.

[0007] The present application creatively adds lanthanum boride, zirconium oxide, boron carbide, cerium oxide, tantalum carbide and modified carbon nanotubes into tungsten powder, which effectively improves the tensile strength and electrical conductivity under the joint action of lanthanum boride, zirconium oxide, boron carbide, cerium oxide, tantalum carbide and modified carbon nanotubes, has excellent high-temperature stability, and has a wide application prospect.

[0008] The zirconium oxide and the cerium oxide can effectively form a doped strengthening phase to inhibit grain boundary migration, the modified carbon nanotubes form a three-dimensional conductive network to inhibit crack propagation, the graphene in the modified carbon nanotubes lubricates the interface between the carbon nanotubes and other components to improve compatibility, the amorphous carbon layer formed by chemical vapor deposition matches the tungsten lattice to avoid abnormal grain growth, effectively reduces the sintering temperature, and improves the density; the dispersed phase formed by the boron carbide and the tantalum carbide effectively improves the high-temperature performance, the lanthanum boride improves the structural stability to prevent high-temperature softening and deformation, and reduces the grain boundary sliding at high temperature; thereby the tungsten alloy electrode material with the specific system of the present application has excellent tensile strength and electrical conductivity, and excellent high-temperature stability.

[0009] As a preferred embodiment of the present invention, the method for preparing the modified carbon nanotubes is as follows: Carbon nanotubes and fullerenes were mixed evenly to obtain a mixture. The mixture, propanol, citric acid, and 3-aminopropyltriethoxysilane were added to water and stirred evenly at 80~100℃. The mixture was then dried to obtain the precursor. The precursor was placed in a chemical vapor deposition furnace for chemical vapor deposition to obtain modified carbon nanotubes.

[0010] In a preferred embodiment of the present invention, the mass ratio of carbon nanotubes to fullerenes is 1:(0.08~0.15).

[0011] As a preferred embodiment of the present invention, the mass ratio of the mixture, propanol, citric acid, 3-aminopropyltriethoxysilane, and water is 1:(0.5~1.2):(0.01~0.02):(0.01~0.02):(2~5).

[0012] As a preferred embodiment of the present invention, the parameters of the chemical vapor deposition are: methane and hydrogen as a mixed gas, temperature of 750~800℃, time of 2~4h, and pressure of 50~100kpa.

[0013] In a preferred embodiment of the present invention, the volume ratio of methane to hydrogen is 1:(3~6).

[0014] In a preferred embodiment of the present invention, the flow rate of the mixed gas is 30~50 sccm.

[0015] This invention also provides a method for preparing a tungsten alloy electrode material, comprising the following steps: (1) Lanthanum boride, zirconium oxide, boron carbide, cerium oxide, tantalum carbide, modified carbon nanotubes and tungsten powder are mixed evenly to obtain a mixture; (2) The mixture is subjected to cold isostatic pressing to obtain a green body; (3) Place the billet in a medium-frequency induction heating furnace and heat it to 800-850℃ at a heating rate of 5-15℃ / min, and hold it for 1-2 hours; then heat it to 1280-1300℃ at a heating rate of 20-25℃ / min, and hold it for 4-6 hours to obtain the precursor material. (4) The precursor material is subjected to hot isostatic pressing sintering, and then drawn, straightened, cut and polished to obtain tungsten alloy electrode material.

[0016] In a preferred embodiment of the present invention, the temperature of the cold isostatic pressing treatment is 15~25℃, the pressure is 160~200Mpa, and the time is 10~16min.

[0017] In a preferred embodiment of the present invention, the hot isostatic pressing sintering treatment is performed at a pressure of 160~200 MPa, a temperature of 1340~1360℃, and a time of 2~4 hours.

[0018] The beneficial effects of this invention are as follows: By adding lanthanum boride, zirconium oxide, boron carbide, cerium oxide, tantalum carbide, and modified carbon nanotubes to tungsten powder, the tensile strength and electrical conductivity are effectively improved under the combined effect of lanthanum boride, zirconium oxide, boron carbide, cerium oxide, tantalum carbide, and modified carbon nanotubes. It also exhibits excellent high-temperature stability and has broad application prospects. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.

[0021] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0022] In this invention, there are no particular limitations on the specific dispersion and stirring methods.

[0023] Unless otherwise specified, all reagents or instruments used in this invention are commercially available conventional products. Unless otherwise specified, the raw materials used in each comparative example and the parallel experiments of each embodiment are the same commercially available products.

[0024] Example 1 A tungsten alloy electrode material comprises the following raw materials in weight percentage: 0.15% lanthanum boride, 0.4% zirconium oxide, 0.5% boron carbide, 0.6% cerium oxide, 1% tantalum carbide, 1.5% modified carbon nanotubes, and the balance being tungsten powder.

[0025] The method for preparing the modified carbon nanotubes is as follows: Carbon nanotubes and fullerenes were mixed evenly at a mass ratio of 1:0.12 to obtain a mixture. The mixture, propanol, citric acid, and 3-aminopropyltriethoxysilane were added to water and stirred evenly at 80~100℃. The mixture was then dried to obtain a precursor. The mass ratio of the mixture, propanol, citric acid, 3-aminopropyltriethoxysilane, and water was 1:1:0.15:0.15:4.

[0026] The precursor was placed in a chemical vapor deposition furnace for chemical vapor deposition to obtain modified carbon nanotubes. The parameters for the chemical vapor deposition were as follows: methane and hydrogen were used as a mixed gas with a volume ratio of 1:4; the flow rate of the mixed gas was 40 sccm; the temperature was 780℃; the time was 3 h; and the pressure was 80 kPa.

[0027] The method for preparing the tungsten alloy electrode material includes the following steps: (1) Lanthanum boride, zirconium oxide, boron carbide, cerium oxide, tantalum carbide, modified carbon nanotubes and tungsten powder are mixed evenly to obtain a mixture; (2) The mixture is subjected to cold isostatic pressing to obtain a blank; the temperature of the cold isostatic pressing is 20°C, the pressure is 180 MPa, and the time is 15 min.

[0028] (3) Place the billet in a medium-frequency induction heating furnace and heat it to 820°C at a heating rate of 10°C / min, and hold it for 1 hour; then heat it to 1280°C at a heating rate of 20°C / min, and hold it for 5 hours to obtain the precursor material. (4) The precursor material is subjected to hot isostatic pressing (HIP) sintering, followed by wire drawing, straightening, cutting, and polishing to obtain tungsten alloy electrode material. The HIP sintering process is carried out at a pressure of 180 MPa, a temperature of 1350 °C, and a time of 3 h.

[0029] Example 2 A tungsten alloy electrode material comprises the following raw materials in weight percentage: 0.1% lanthanum boride, 0.5% zirconium oxide, 0.2% boron carbide, 0.8% cerium oxide, 0.5% tantalum carbide, 1.8% modified carbon nanotubes, and the balance being tungsten powder.

[0030] The method for preparing the modified carbon nanotubes is as follows: Carbon nanotubes and fullerenes were mixed evenly at a mass ratio of 1:0.12 to obtain a mixture. The mixture, propanol, citric acid, and 3-aminopropyltriethoxysilane were added to water and stirred evenly at 80~100℃. The mixture was then dried to obtain a precursor. The mass ratio of the mixture, propanol, citric acid, 3-aminopropyltriethoxysilane, and water was 1:1:0.15:0.15:4.

[0031] The precursor was placed in a chemical vapor deposition furnace for chemical vapor deposition to obtain modified carbon nanotubes. The parameters for the chemical vapor deposition were as follows: methane and hydrogen were used as a mixed gas with a volume ratio of 1:4; the flow rate of the mixed gas was 40 sccm; the temperature was 780℃; the time was 3 h; and the pressure was 80 kPa.

[0032] The method for preparing the tungsten alloy electrode material includes the following steps: (1) Lanthanum boride, zirconium oxide, boron carbide, cerium oxide, tantalum carbide, modified carbon nanotubes and tungsten powder are mixed evenly to obtain a mixture; (2) The mixture is subjected to cold isostatic pressing to obtain a blank; the temperature of the cold isostatic pressing is 20°C, the pressure is 180 MPa, and the time is 15 min.

[0033] (3) Place the billet in a medium-frequency induction heating furnace and heat it to 820°C at a heating rate of 10°C / min, and hold it for 1 hour; then heat it to 1280°C at a heating rate of 20°C / min, and hold it for 5 hours to obtain the precursor material. (4) The precursor material is subjected to hot isostatic pressing (HIP) sintering, followed by wire drawing, straightening, cutting, and polishing to obtain tungsten alloy electrode material. The HIP sintering process is carried out at a pressure of 180 MPa, a temperature of 1350 °C, and a time of 3 h.

[0034] Example 3 A tungsten alloy electrode material comprises the following raw materials in weight percentage: 0.2% lanthanum boride, 0.2% zirconium oxide, 0.6% boron carbide, 0.4% cerium oxide, 1.2% tantalum carbide, 1.4% modified carbon nanotubes, and the balance being tungsten powder.

[0035] The method for preparing the modified carbon nanotubes is as follows: Carbon nanotubes and fullerenes were mixed evenly at a mass ratio of 1:0.12 to obtain a mixture. The mixture, propanol, citric acid, and 3-aminopropyltriethoxysilane were added to water and stirred evenly at 80~100℃. The mixture was then dried to obtain a precursor. The mass ratio of the mixture, propanol, citric acid, 3-aminopropyltriethoxysilane, and water was 1:1:0.15:0.15:4.

[0036] The precursor was placed in a chemical vapor deposition furnace for chemical vapor deposition to obtain modified carbon nanotubes. The parameters for the chemical vapor deposition were as follows: methane and hydrogen were used as a mixed gas with a volume ratio of 1:4; the flow rate of the mixed gas was 40 sccm; the temperature was 780℃; the time was 3 h; and the pressure was 80 kPa.

[0037] The method for preparing the tungsten alloy electrode material includes the following steps: (1) Lanthanum boride, zirconium oxide, boron carbide, cerium oxide, tantalum carbide, modified carbon nanotubes and tungsten powder are mixed evenly to obtain a mixture; (2) The mixture is subjected to cold isostatic pressing to obtain a blank; the temperature of the cold isostatic pressing is 20°C, the pressure is 180 MPa, and the time is 15 min.

[0038] (3) Place the billet in a medium-frequency induction heating furnace and heat it to 820°C at a heating rate of 10°C / min, and hold it for 1 hour; then heat it to 1280°C at a heating rate of 20°C / min, and hold it for 5 hours to obtain the precursor material. (4) The precursor material is subjected to hot isostatic pressing (HIP) sintering, followed by wire drawing, straightening, cutting, and polishing to obtain tungsten alloy electrode material. The HIP sintering process is carried out at a pressure of 180 MPa, a temperature of 1350 °C, and a time of 3 h.

[0039] Comparative Example 1

[0040] The difference between Comparative Example 1 and Example 1 is that the amount of each raw material used in Comparative Example 1 deviates from the scope of the present invention, while all other aspects are the same.

[0041] A tungsten alloy electrode material comprises the following raw materials in weight percentage: 0.05% lanthanum boride, 0.8% zirconium oxide, 0.1% boron carbide, 1% cerium oxide, 0.1% tantalum carbide, 3% modified carbon nanotubes, and the balance being tungsten powder.

[0042] Comparative Example 2

[0043] The difference between Comparative Example 2 and Example 1 is that the amount of each raw material used in Comparative Example 2 deviates from the scope of the present invention, while everything else is the same.

[0044] A tungsten alloy electrode material comprises the following raw materials in weight percentage: 0.4% lanthanum boride, 0.1% zirconium oxide, 1% boron carbide, 0.1% cerium oxide, 1.5% tantalum carbide, 1% modified carbon nanotubes, and the balance being tungsten powder.

[0045] Comparative Example 3

[0046] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 uses carbon nanotubes instead of modified carbon nanotubes, but everything else is the same.

[0047] A tungsten alloy electrode material comprises the following raw materials in weight percentage: 0.15% lanthanum boride, 0.4% zirconium oxide, 0.5% boron carbide, 0.6% cerium oxide, 1% tantalum carbide, 1.5% carbon nanotubes, and the balance being tungsten powder.

[0048] Comparative Example 4

[0049] The difference between Comparative Example 4 and Example 1 is that the preparation method of the modified carbon nanotubes in Comparative Example 4 is different from that in Example 1, but all other aspects are the same.

[0050] Carbon nanotubes and fullerenes were mixed evenly at a mass ratio of 1:0.12 to obtain a mixture. The mixture, propanol, citric acid, and 3-aminopropyltriethoxysilane were added to water and stirred evenly at 80~100℃. The mixture was then dried to obtain modified carbon nanotubes. The mass ratio of the mixture, propanol, citric acid, 3-aminopropyltriethoxysilane, and water was 1:1:0.15:0.15:4.

[0051] Comparative Example 5

[0052] The difference between Comparative Example 5 and Example 1 is that the preparation method of the modified carbon nanotubes in Comparative Example 5 is different from that in Example 1, but all other aspects are the same.

[0053] Carbon nanotubes were placed in a chemical vapor deposition furnace for chemical vapor deposition to obtain modified carbon nanotubes. The parameters for the chemical vapor deposition were as follows: methane and hydrogen were used as a mixed gas with a volume ratio of 1:4; the flow rate of the mixed gas was 40 sccm; the temperature was 780℃; the time was 3 h; and the pressure was 80 kPa.

[0054] Test case

[0055] 1. The tensile strength of the examples and comparative examples was tested at 300°C.

[0056] 2. Test the room temperature (25°C) conductivity of the examples and comparative examples.

[0057] Table 1

[0058] As can be seen from Table 1, the tungsten alloy electrode material of the present invention has excellent tensile strength and electrical conductivity, and excellent high-temperature stability.

[0059] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A tungsten alloy electrode material, characterized in that, The raw materials include the following weight percentages: 0.1~0.2% lanthanum boride, 0.2~0.5% zirconium oxide, 0.2~0.6% boron carbide, 0.4~0.8% cerium oxide, 0.5~1.2% tantalum carbide, 1.4~1.8% modified carbon nanotubes, and the balance tungsten powder.

2. The tungsten alloy electrode material according to claim 1, characterized in that, The method for preparing the modified carbon nanotubes is as follows: Carbon nanotubes and fullerenes were mixed evenly to obtain a mixture. The mixture, propanol, citric acid, and 3-aminopropyltriethoxysilane were added to water and stirred evenly at 80~100℃. The mixture was then dried to obtain the precursor. The precursor was placed in a chemical vapor deposition furnace for chemical vapor deposition to obtain modified carbon nanotubes.

3. The tungsten alloy electrode material according to claim 2, characterized in that, The mass ratio of carbon nanotubes to fullerenes is 1:(0.08~0.15).

4. The tungsten alloy electrode material according to claim 2, characterized in that, The mass ratio of the mixture, propanol, citric acid, 3-aminopropyltriethoxysilane, and water is 1:(0.5~1.2):(0.01~0.02):(0.01~0.02):(2~5).

5. The tungsten alloy electrode material according to claim 2, characterized in that, The parameters for the chemical vapor deposition are: a mixture of methane and hydrogen, a temperature of 750-800℃, a time of 2-4 hours, and a pressure of 50-100 kPa.

6. The tungsten alloy electrode material according to claim 5, characterized in that, The volume ratio of methane to hydrogen is 1:(3~6).

7. The tungsten alloy electrode material according to claim 5, characterized in that, The flow rate of the mixed gas is 30~50 sccm.

8. The method for preparing the tungsten alloy electrode material according to any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Lanthanum boride, zirconium oxide, boron carbide, cerium oxide, tantalum carbide, modified carbon nanotubes and tungsten powder are mixed evenly to obtain a mixture; (2) The mixture is subjected to cold isostatic pressing to obtain a green body; (3) Place the billet in a medium-frequency induction heating furnace and heat it to 800-850℃ at a heating rate of 5-15℃ / min, and hold it for 1-2 hours; then heat it to 1280-1300℃ at a heating rate of 20-25℃ / min, and hold it for 4-6 hours to obtain the precursor material. (4) The precursor material is subjected to hot isostatic pressing sintering, and then drawn, straightened, cut and polished to obtain tungsten alloy electrode material.

9. The method for preparing the tungsten alloy electrode material according to claim 8, characterized in that, The cold isostatic pressing process is performed at a temperature of 15~25℃, a pressure of 160~200Mpa, and a time of 10~16min.

10. The method for preparing the tungsten alloy electrode material according to claim 8, characterized in that, The hot isostatic pressing sintering treatment is performed at a pressure of 160~200 MPa, a temperature of 1340~1360℃, and a time of 2~4 hours.

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