阅读说明：本技术 熔盐电解用钨阴极及其制备方法和激光熔覆技术的用途 (Tungsten cathode for molten salt electrolysis, preparation method thereof and application of laser cladding technology ) 是由 张鸣一 高平 王昊 于 2021-09-29 设计创作，主要内容包括：本发明公开了一种熔盐电解用钨阴极的制备方法,包括如下步骤：在钨基体的待激光熔覆的表面依次激光熔覆铜、不锈钢和抗腐蚀金属复合材料,得到具有铜熔覆层、不锈钢熔覆层和抗腐蚀金属熔覆层的钨阴极；其中,所述待激光熔覆的表面为自钨基体的同一端部起,钨基体长度的1/10处至钨基体长度的1/4处之间区域的钨基体表面；所述抗腐蚀金属复合材料由如下成分组成：C 0.02wt％～0.06wt％、Si 1.5wt％～2.5wt％、W 2.5wt％～3.5wt％、Fe≤7wt％、Mo10wt％～20wt％、Cr 20wt％～30wt％、ZrO 8wt％～20wt％、B0.4wt％～0.8wt％和余量的Ni。该方法可将传统钨阴极的使用寿命由200天左右延长至310～320天。(The invention discloses a preparation method of a tungsten cathode for molten salt electrolysis, which comprises the following steps: sequentially carrying out laser cladding on the surface to be subjected to laser cladding on the tungsten substrate to obtain a tungsten cathode with a copper cladding layer, a stainless steel cladding layer and an anti-corrosion metal cladding layer; the surface to be laser-clad is the tungsten substrate surface in the area from the same end of the tungsten substrate to the position from 1/10 of the length of the tungsten substrate to 1/4 of the length of the tungsten substrate; the corrosion-resistant metal composite material comprises the following components: 0.02 to 0.06 weight percent of C, 1.5 to 2.5 weight percent of Si, 2.5 to 3.5 weight percent of W, less than or equal to 7 weight percent of Fe, 10 to 20 weight percent of Mo, 20 to 30 weight percent of Cr, 8 to 20 weight percent of ZrO, 0.4 to 0.8 weight percent of B0.06 weight percent and the balance of Ni. The method can prolong the service life of the traditional tungsten cathode from about 200 days to 310-320 days.)

1. A preparation method of a tungsten cathode for molten salt electrolysis is characterized by comprising the following steps:

sequentially carrying out laser cladding on the surface to be subjected to laser cladding on the tungsten substrate to obtain a tungsten cathode with a copper cladding layer, a stainless steel cladding layer and an anti-corrosion metal cladding layer; wherein the content of the first and second substances,

the surface to be laser-clad is the tungsten substrate surface in the area from the same end of the tungsten substrate to the position from 1/10 of the length of the tungsten substrate to 1/4 of the length of the tungsten substrate;

the corrosion-resistant metal composite material comprises the following components: 0.02 to 0.06 weight percent of C, 1.5 to 2.5 weight percent of Si, 2.5 to 3.5 weight percent of W, less than or equal to 7 weight percent of Fe, 10 to 20 weight percent of Mo, 20 to 30 weight percent of Cr, 8 to 20 weight percent of ZrO, 0.4 to 0.8 weight percent of B and the balance of Ni.

2. The method of claim 1, further comprising the steps of: and carrying out surface treatment and annealing on the tungsten cathode with the copper cladding layer, the stainless steel cladding layer and the corrosion-resistant metal cladding layer to obtain the tungsten cathode for molten salt electrolysis.

3. The production method according to claim 2, wherein the surface treatment comprises: and respectively adopting a paddle wheel, a hemp wheel and a cotton wheel to carry out rough polishing, middle polishing and fine polishing on the tungsten cathode, and then wiping the surface of the polished tungsten cathode.

4. The preparation method according to claim 3, wherein the annealing temperature is 200-350 ℃ and the holding time is 6-8 h.

5. The production method according to any one of claims 1 to 4, wherein the tungsten substrate is selected from a tungsten rod subjected to surface blasting; the copper is selected from spherical copper powder with the granularity of 300-500 meshes; the stainless steel is selected from 316L stainless steel spherical powder with the granularity of 300-500 meshes; the particle size of the corrosion-resistant metal composite material is 300-500 meshes.

6. The method according to any one of claims 1 to 4, wherein the process parameters of laser melting the copper are as follows: the output power of the laser cladding equipment is 4.5-5.5 kW, the powder feeding speed is 16-18 g/min, the protective gas flow is 18-20L/min, and the powder feeding gas flow is 1.4-1.6L/min;

the process parameters of laser cladding stainless steel are as follows: the output power of the laser cladding equipment is 3-4 kW, the powder feeding speed is 14-17 g/min, the protective gas flow is 16-18L/min, and the powder feeding gas flow is 1.2-1.5L/min;

the process parameters of laser cladding the corrosion-resistant metal composite material are as follows: the output power of the laser cladding equipment is 3.5-4.5 kW, the powder feeding speed is 14-17 g/min, the protective gas flow is 16-18L/min, and the powder feeding gas flow is 1.2-1.5L/min;

the laser cladding adopts ultra-high speed laser cladding equipment with rated power more than or equal to 6 kW.

7. The production method according to any one of claims 1 to 4, wherein the thickness of the copper cladding layer is 1.8 to 2.2 mm; the thickness of the stainless steel cladding layer is 1-1.5 mm; the thickness of the corrosion-resistant metal cladding layer is 1.5-2.0 mm.

8. A tungsten cathode for molten salt electrolysis, characterized by being produced by the production method according to any one of claims 1 to 7.

9. The tungsten cathode for molten salt electrolysis according to claim 8, characterized in that the tungsten cathode for molten salt electrolysis has a service life of more than 310 days.

10. The application of a laser cladding technology in improving the corrosion resistance of a tungsten cathode is characterized in that a corrosion-resistant material is laser cladded on a tungsten substrate.

Technical Field

The invention relates to a tungsten cathode for molten salt electrolysis and a preparation method thereof, and also relates to application of a laser cladding technology.

Background

When rare earth metal is prepared by adopting a rare earth molten salt electrolysis method, fluoride and oxide are mostly adopted as molten salt electrolyte, the current during electrolysis is up to thousands of amperes, the temperature of the electrolyte can reach over 1000 ℃, and the working condition is very severe, so that metal with strong corrosion resistance and high melting property is required to be selected as a cathode. Currently, tungsten cathodes are generally used in production.

In practical production, the tungsten cathode exposed above the molten salt liquid level (especially the part close to the molten salt liquid level) is exposed under the high-temperature condition of 700-850 ℃ for a long time and is easy to be impacted by the airflow of volatile gas, and the part is easy to be oxidized, so that the corrosion and the failure of the tungsten cathode are caused. Because tungsten belongs to rare metal and is expensive, frequent replacement of the tungsten cathode not only increases the production cost, but also affects the production efficiency. Therefore, it is necessary to develop a new process for improving the corrosion resistance of the tungsten cathode material and prolonging the service life of the tungsten cathode.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a method for preparing a tungsten cathode for molten salt electrolysis, which can improve the corrosion resistance of the tungsten cathode and prolong the service life of the tungsten cathode.

The invention also aims to provide the high-temperature-resistant and corrosion-resistant tungsten cathode for molten salt electrolysis.

It is a further object of the present invention to provide the use of a laser cladding technique for improving the corrosion resistance of tungsten cathodes.

In one aspect, the invention provides a preparation method of a tungsten cathode for molten salt electrolysis, which comprises the following steps:

sequentially carrying out laser cladding on the surface to be subjected to laser cladding on the tungsten substrate to obtain a tungsten cathode with a copper cladding layer, a stainless steel cladding layer and an anti-corrosion metal cladding layer; wherein the content of the first and second substances,

the surface of the tungsten substrate to be subjected to laser cladding is the surface of the tungsten substrate in the area from the same end of the tungsten substrate to the position from 1/10 of the length of the tungsten substrate to 1/4 of the length of the tungsten substrate;

the corrosion-resistant metal composite material comprises the following components: 0.02 to 0.06 weight percent of C, 1.5 to 2.5 weight percent of Si, 2.5 to 3.5 weight percent of W, less than or equal to 7 weight percent of Fe, 10 to 20 weight percent of Mo, 20 to 30 weight percent of Cr, 8 to 20 weight percent of ZrO, 0.4 to 0.8 weight percent of B0.06 weight percent and the balance of Ni.

According to some embodiments of the invention, the corrosion resistant metal composite is comprised of: 0.03 to 0.06 weight percent of C, 2 to 2.5 weight percent of Si, 3 to 3.5 weight percent of W, less than or equal to 5 weight percent of Fe, 14 to 15 weight percent of Mo, 23 to 26 weight percent of Cr, 13 to 17 weight percent of ZrO13wt, 0.6 to 0.8 weight percent of B and the balance of Ni. The corrosion-resistant metal composite material prepared according to the proportion has high-temperature resistance and corrosion resistance, and is good in laser cladding effect and not easy to fall off.

As shown in fig. 1, the cladding region of the present invention includes a middle region 1 and an end region 2. The thickness of each cladding layer of the end region 2 is gradually increased from the end part to the middle part of the cladding region; the thickness of each cladding layer of the middle region 1 is equal to the maximum thickness of each cladding layer of the end regions 2. Therefore, the internal stress generated by the tungsten cathode in the using process can be reduced, and the cracking or falling of the cladding layer can be avoided. In the present invention, the thickness of the copper cladding layer, the thickness of the stainless steel cladding layer, and the thickness of the corrosion-resistant metal cladding layer all refer to the thickness of the cladding layer in the middle region 1.

The preparation method according to the present invention preferably further comprises the steps of: and carrying out surface treatment and annealing on the tungsten cathode with the copper cladding layer, the stainless steel cladding layer and the corrosion-resistant metal cladding layer to obtain the tungsten cathode for molten salt electrolysis.

According to the production method of the present invention, preferably, the surface treatment includes: and respectively adopting a paddle wheel, a hemp wheel and a cotton wheel to carry out rough polishing, middle polishing and fine polishing on the tungsten cathode, and then wiping the surface of the polished tungsten cathode.

According to some embodiments of the invention, the specific process of surface treatment is: firstly, leveling by adopting a shutter wheel, and roughly polishing; then a hemp wheel (special fiber wheel) is used for middle throwing; then, finely polishing by using a cotton wheel, and cooperatively using polishing paste; and finally, polishing the surface of the polished tungsten cathode. Therefore, the residual fine melting channel on the metal surface after cladding can be reduced, and the erosion resistance of the tungsten cathode is improved.

According to the preparation method provided by the invention, preferably, the annealing temperature is 200-350 ℃, and the heat preservation time is 6-8 h.

According to some embodiments of the invention, the annealing temperature is 200-250 ℃ and the holding time is 6-8 h. Under the annealing condition, the internal stress of the tungsten substrate and the cladding layer can be effectively removed, and the internal stress crack or the surface stress crack of the tungsten cathode is prevented when the tungsten cathode is used.

In the invention, the copper cladding layer can be copper powder; preferably copper powder with the granularity of 300-500 meshes; more preferably, spherical pure copper powder with the granularity of 300-500 meshes is subjected to laser cladding. Because tungsten belongs to refractory metal, and the tungsten cathode is prepared by adopting a sintering process, the strength of the tungsten cathode is very low, and the traditional welding process or the common laser cladding process is adopted, so that on one hand, a tungsten matrix is difficult to melt to form a molten pool for surfacing, and on the other hand, when an anti-corrosion metal composite material is directly cladded on the surface of the tungsten matrix, the tungsten matrix is easy to crack by pulling, and a cladding layer is easy to fall off. Aiming at the phenomenon, the invention discovers that pure copper can fill up the gap generated by sintering the tungsten cathode, so that the matrix is more compact, and the cooling process of laser melting copper can not generate larger pulling force on the tungsten matrix, thereby effectively preventing the tungsten matrix from being pulled to crack. In addition, the bonding force between the copper cladding layer and the tungsten matrix is high, the cladding layer is not easy to fall off, and the service life of the tungsten cathode for molten salt electrolysis is prolonged.

In the invention, the stainless steel cladding layer can be made of stainless steel; preferably 316L stainless steel; more preferably 316L stainless steel spherical powder with the granularity of 300-500 meshes for laser cladding. Researches show that the corrosion-resistant metal composite material is directly cladded on the copper cladding layer, so that the corrosion-resistant metal cladding layer is cracked and even falls off, and the stainless steel is selected as a transition metal layer, so that the corrosion-resistant metal cladding layer can be prevented from being cracked and falling off, and the fusion effect among the cladding layers can be improved. In addition, the corrosion resistance of the tungsten cathode can be further improved by selecting 316L stainless steel.

According to the production method of the present invention, preferably, the tungsten substrate is selected from a tungsten rod subjected to surface blasting; the copper is selected from spherical copper powder with the granularity of 300-500 meshes; the stainless steel is selected from 316L stainless steel spherical powder with the granularity of 300-500 meshes; the particle size of the corrosion-resistant metal composite material is 300-500 meshes.

According to some embodiments of the present invention, the surface of the tungsten rod is first subjected to sand blasting, so that impurities on the surface of the tungsten rod can be removed, the surface roughness of the tungsten substrate can be increased, the adhesion area of cladding can be increased, and the bonding effect can be enhanced.

According to other embodiments of the present invention, the copper is selected from spherical copper powder having a particle size of 300 to 500 mesh; the stainless steel is selected from 316L stainless steel spherical powder with the granularity of 300-500 meshes; the particle size of the corrosion-resistant metal composite material is 300-500 meshes of powder. When the granularity of the copper/stainless steel/corrosion-resistant metal composite material is larger than 500 meshes, the powder is not fully melted during cladding, and the fusion effect is poor; when the granularity of the copper/stainless steel/corrosion-resistant metal composite material is less than 300 meshes, the powder is easy to burn and the dust is large during powder spraying.

According to the preparation method of the invention, preferably, the process parameters of laser melting copper are as follows: the output power of the laser cladding equipment is 4.5-5.5 kW, the powder feeding speed is 16-18 g/min, the protective gas flow is 18-20L/min, and the powder feeding gas flow is 1.4-1.6L/min;

the process parameters of laser cladding stainless steel are as follows: the output power of the laser cladding equipment is 3-4 kW, the powder feeding speed is 14-17 g/min, the protective gas flow is 16-18L/min, and the powder feeding gas flow is 1.2-1.5L/min;

the process parameters of laser cladding the corrosion-resistant metal composite material are as follows: the output power of the laser cladding equipment is 3.5-4.5 kW, the powder feeding speed is 14-17 g/min, the protective gas flow is 16-18L/min, and the powder feeding gas flow is 1.2-1.5L/min;

the laser cladding adopts ultra-high speed laser cladding equipment with rated power more than or equal to 6 kW.

The ultra-high speed laser cladding equipment is laser cladding equipment with the linear speed of 100m/min, the dilution rate of less than 3 percent and the spot diameter of less than 1 mm. For example, ZKZM-3256 model of Mediterranean laser technology Limited in West Ann.

According to some embodiments of the invention, the ultra-high-speed laser cladding equipment with the power of more than or equal to 6kW is adopted, so that the defects of low welding power, large heat affected zone to the substrate, poor welding uniformity and the like of common laser cladding equipment can be overcome, and the tension crack of the tungsten substrate in the laser cladding process and the cracking and chipping of the surface of the cladding layer after the cladding are finished are effectively reduced.

According to other embodiments of the present invention, when the output power of the laser cladding apparatus is lower than the lower limit of the above range, a molten pool cannot be formed, resulting in poor fusion effect of each cladding layer; when the output power of the laser cladding equipment is higher than the upper limit of the range, cladding metal is burnt, the surface smoothness of a cladding layer is reduced, the thermal stress is increased, and the cracking tendency is increased.

According to still other embodiments of the present invention, when the powder feeding speed is lower than the lower limit of the above range, the thickness of the cladding layer may be insufficient and the uniformity of the cladding layer may be degraded; when the powder feeding speed is higher than the upper limit of the above range, the clad metal powder cannot be completely melted, and the fusion effect is poor.

According to the preparation method provided by the invention, preferably, the thickness of the copper cladding layer is 1.8-2.2 mm; the thickness of the stainless steel cladding layer is 1-1.5 mm; the thickness of the corrosion-resistant metal cladding layer is 1.5-2.0 mm.

According to some embodiments of the invention, the copper cladding layer has a thickness of 1.8 to 2.2 mm; the thickness of the stainless steel cladding layer is 1.3-1.5 mm; the thickness of the corrosion-resistant metal cladding layer is 1.5-2.0 mm. Therefore, the high-temperature oxidation resistance and the corrosion resistance (acid corrosion and salt corrosion) of the tungsten cathode can be enhanced to the maximum extent at lower cost, and the fusion effect among layers is ensured to prevent the tungsten cathode from falling off.

In another aspect, the present invention provides a tungsten cathode for molten salt electrolysis prepared by the above preparation method.

The tungsten cathode for molten salt electrolysis has the service life of more than 310 days. According to some embodiments of the invention, the tungsten cathode for molten salt electrolysis has a lifetime of 311 to 320 days.

In another aspect, the invention provides an application of a laser cladding technology in improving the corrosion resistance of a tungsten cathode, and the laser cladding technology is used for laser cladding of a corrosion-resistant material on a tungsten substrate. The laser cladding technology is successfully applied to refractory metal (tungsten matrix). The use may include the steps of the above-described preparation method, which are not described in detail herein.

The preparation method adopts the laser cladding technology, and sequentially melts the copper, the stainless steel and the corrosion-resistant metal composite material on the surface of the tungsten substrate, thereby overcoming the technical problems that the tungsten substrate is easy to crack during laser cladding, and the formed cladding layer is easy to crack and fall off; and the fusion effect among each layer of cladding layer is good, the corrosion resistance of the tungsten cathode can be effectively improved, and the service life of the traditional tungsten cathode can be prolonged from about 200 days to 310-320 days.

Drawings

Fig. 1 is a longitudinal sectional view of a tungsten cathode of the present invention.

The reference numbers are as follows: 1-a middle region; 2-end region_。

Detailed Description

The present invention will be further described with reference to specific embodiments, but the scope of the present invention is not limited thereto.

The materials, equipment and test methods used in the examples and comparative examples are as follows:

(1) the laser cladding equipment comprises: ZKZM-3256 type ultra-high speed laser cladding equipment of Sienna Zhongmei laser technology Co., Ltd, wherein the rated power of the equipment is 6 kW;

in the invention, the output power of the laser cladding equipment is equal to the rated power multiplied by the power output ratio of the equipment;

(2) spherical pure copper powder and 316L stainless steel spherical powder: all purchased from Xindun alloy welding material spraying Co., Ltd, Nangong City;

(3) testing conditions of the service life of the tungsten cathode are as follows: the electrolyte is mixed molten salt of rare earth fluoride and lithium fluoride, the electrolysis temperature is 1100 ℃, and the electrolysis current is 8000A.

Example 1

(1) Preparation of corrosion-resistant metal composite

Weighing the raw materials according to the following mixture ratio: 0.03 wt% of C, 2.0 wt% of Si, 3.0 wt% of W, 5 wt% of Fe, 14 wt% of Mo, 23 wt% of Cr, 15 wt% of ZrO, 0.6 wt% of B and the balance of Ni; the sum of the weight percentages of the components is 100 wt%.

The raw materials are placed in a planetary ball mill for refining and uniform mixing to obtain the corrosion-resistant metal composite material with the granularity of 300 meshes.

(2) Pretreatment of tungsten rods

Taking a tungsten rod with the diameter of 80mm and the length of 1000mm, and carrying out surface purification and texturing treatment on the tungsten rod by adopting a sand blasting process to obtain the tungsten rod subjected to surface sand blasting treatment.

(3) Laser cladding

Spherical pure copper powder with the granularity of 300 meshes, 316L stainless steel spherical powder with the granularity of 300 meshes and an anti-corrosion metal composite material with the granularity of 300 meshes are respectively placed in laser cladding equipment, and the tungsten rod subjected to surface sand blasting treatment is subjected to laser cladding (the cladding area is an area which is 120-250 mm away from the end part of the tungsten rod), so that a tungsten cathode with a copper cladding layer, a stainless steel cladding layer and an anti-corrosion metal cladding layer is obtained;

the laser cladding copper adopts a cladding process with high power and low powder feeding rate, and the specific process parameters are as follows: power output ratio of 85%, powder feeding speed of 17g/min, protective gas amount: 18L/min, powder feeding gas: 1.5L/min, the cladding thickness is 2.0 mm;

the laser cladding stainless steel adopts a cladding process with medium power and medium powder feeding speed, and the specific process parameters are as follows: the power output ratio is 60%, the powder feeding speed is 16g/min, and the protective gas amount is as follows: 17L/min, powder feeding gas: 1.3L/min, the cladding thickness is 1.3 mm;

the laser cladding corrosion-resistant metal composite material adopts a cladding process with low power and medium powder feeding speed, and the specific process parameters are as follows: the power output ratio is 62%, the powder feeding speed is 16g/min, and the protective gas amount is as follows: 18L/min, powder feeding gas: 1.4L/min, and the cladding thickness is 1.8 mm.

(4) Surface treatment and annealing

Leveling the tungsten cathode by adopting a shutter wheel, and performing rough polishing; then a hemp wheel (special fiber wheel) is used for middle throwing; then, finely polishing by using a cotton wheel, and cooperatively using polishing paste; and finally, polishing the surface of the polished tungsten cathode, and placing the polished tungsten cathode in a resistance furnace for annealing treatment at the annealing temperature of 200 ℃ for 8 hours to obtain the tungsten cathode for molten salt electrolysis.

The service life of the tungsten cathode is tested, and the test result shows that the service cycle of the tungsten cathode is 311 days.

Example 2

The procedure was as in example 1 except for the following steps.

(3) Laser cladding

Spherical pure copper powder with the granularity of 300 meshes, 316L stainless steel spherical powder with the granularity of 300 meshes and an anti-corrosion metal composite material with the granularity of 300 meshes are respectively placed in laser cladding equipment, and a tungsten rod subjected to surface sand blasting treatment is subjected to laser cladding to obtain a tungsten cathode with a copper cladding layer, a stainless steel cladding layer and an anti-corrosion metal cladding layer;

the laser cladding copper adopts a cladding process with high power and low powder feeding rate, and the specific process parameters are as follows: power output ratio of 82%, powder feeding speed of 16g/min, protective gas amount: 18L/min, powder feeding gas: 1.4L/min, and the cladding thickness is 1.8 mm;

the laser cladding stainless steel adopts a cladding process with medium power and medium powder feeding speed, and the specific process parameters are as follows: the power output ratio is 65%, the powder feeding speed is 17g/min, and the protective gas amount is as follows: 18L/min, powder feeding gas: 1.4L/min, and the cladding thickness is 1.5 mm;

the laser cladding corrosion-resistant metal composite material adopts a cladding process with low power and medium powder feeding speed, and the specific process parameters are as follows: the power output ratio is 60%, the powder feeding speed is 17g/min, and the protective gas amount is as follows: 18L/min, powder feeding gas: 1.4L/min, and the cladding thickness is 1.5 mm.

The service life of the tungsten cathode is tested, and the test result shows that the service cycle of the tungsten cathode is 315 days.

Example 3

The procedure was as in example 1 except for the following steps.

(3) Laser cladding

Spherical pure copper powder with the granularity of 500 meshes, 316L stainless steel spherical powder with the granularity of 500 meshes and an anti-corrosion metal composite material with the granularity of 500 meshes are respectively placed in laser cladding equipment, and the tungsten rod subjected to surface sand blasting treatment is subjected to laser cladding (the cladding area is an area which is 120-250 mm away from the end part of the tungsten rod), so that a tungsten cathode with a copper cladding layer, a stainless steel cladding layer and an anti-corrosion metal cladding layer is obtained;

the laser cladding copper adopts a cladding process with high power and low powder feeding rate, and the specific process parameters are as follows: power output ratio of 88%, powder feeding speed of 18g/min, protective gas amount: 18L/min, powder feeding gas: 1.6L/min, and the cladding thickness is 2.2 mm;

the laser cladding stainless steel adopts a cladding process with medium power and medium powder feeding speed, and the specific process parameters are as follows: the power output ratio is 65%, the powder feeding speed is 17g/min, and the protective gas amount is as follows: 18L/min, powder feeding gas: 1.5L/min, and the cladding thickness is 1.5 mm;

the laser cladding corrosion-resistant metal composite material adopts a cladding process with low power and medium powder feeding speed, and the specific process parameters are as follows: power output ratio of 70%, powder feeding speed of 17g/min, protective gas amount: 18L/min, powder feeding gas: 1.5L/min, and the cladding thickness is 2.0 mm.

The service life of the tungsten cathode is tested, and the test result shows that the service cycle of the tungsten cathode is 320 days.

Comparative example 1

The tungsten rod with the diameter of 80mm and the length of 1000mm is used as a tungsten cathode, the service life of the tungsten cathode is tested, and the test result shows that the service cycle of the tungsten cathode is 201 days.

Under the same working condition, the service life of the untreated tungsten cathode is 201 days, while the service life of the tungsten cathode prepared by the preparation method is 311-320 days, and is prolonged by more than 54%. The above results show that the service life of the tungsten cathode prepared by the invention is more than 310 days.

The present invention is not limited to the above-described embodiments, and any variations, modifications, and substitutions which may occur to those skilled in the art may be made without departing from the spirit of the invention.