阅读说明：本技术 激光在等离子体合金化触头表面原位生长石墨烯的方法 (Method for in-situ growth of graphene on surface of plasma alloying contact by laser ) 是由 孙起辉 叶晓慧 张科 于 2021-05-27 设计创作，主要内容包括：一种激光在等离子体合金化触头表面原位生长石墨烯的方法,通过等离子体合金化制备镍/金属触头材料；再通过激光加热在触头表面生长石墨烯,从而赋予复合触头材料接触界面高热导率、高电导率的物理性质和优异的机械性能,弥补了合金材料的缺点,并在工程领域更大化石墨烯特殊性能的应用。本发明提高了触头材料抗电弧烧蚀能力、抗熔焊能力、机械性能,为轨道交通和电气设备的升级改造提供理论依据和经验指导。(A method for growing graphene on the surface of a plasma alloying contact in situ by laser is characterized in that a nickel/metal contact material is prepared by plasma alloying; and then graphene grows on the surface of the contact through laser heating, so that the composite contact material is endowed with physical properties of high thermal conductivity, high electrical conductivity and excellent mechanical properties of a contact interface, the defects of alloy materials are overcome, and the application of the special performance of the graphene in the engineering field is enlarged. The invention improves the arc ablation resistance, fusion welding resistance and mechanical property of the contact material, and provides theoretical basis and empirical guidance for upgrading and reconstructing rail transit and electrical equipment.)

1. A method for in-situ growth of graphene on the surface of a plasma alloying contact by laser is characterized in that,

s1, preparing required raw material components according to target components, introducing metallic nickel by adopting a plasma alloying process, wherein in the alloying process, the current is 100-200A, the arc striking height of a plasma gun is 2.5-3.5 mm, the scanning speed is 200-500 mm/min, the feeding rate is 15-30 g/min, a nickel/metal material melt is subjected to multilayer reciprocating jet deposition under the protection action of protective gas, the thickness of each layer is 1.5-2.0 mm, the nickel/metal material melt is subjected to jet deposition on a substrate under the carrying action of ionic gas and the protective gas, and finally the nickel/copper contact material is prepared by plasma alloying;

s2, pre-coating a solid carbon source on the surface of the nickel/copper contact material, and then heating by using laser to realize in-situ growth of graphene; the laser power is 2000-6000W, the spot diameter is 50-500 μm, the laser power is 1500-5500W, and the scanning speed is 1-50 mm/s.

2. The method for in-situ growth of graphene on the surface of the plasma alloying contact by laser according to claim 1, wherein in the step S1, the particle size of the metal nickel and copper is 1-100 μm.

3. The method of claim 1, wherein in step S1, the contact material comprises copper oxide alloy, copper-nickel alloy, copper-carbon alloy, copper-tungsten alloy and/or copper-tungsten-carbon alloy.

4. The method for in-situ growth of graphene on the surface of the plasma alloying contact through laser according to claim 1, wherein in the step S2, in the process of in-situ growth of graphene through laser heating, the laser adopts fiber laser and CO₂Laser or semiconductor laser.

5. The method for in-situ growth of graphene on the surface of the plasma alloying contact through the laser according to claim 1, wherein in the step S2, the solid carbon source is graphite powder, and the thickness of the preset layer is 5-50 μm.

6. The method for in-situ growth of graphene on the surface of the plasma alloying contact by laser according to claim 1, wherein the particle size of the graphite powder in the step S2 is 30-100 nm.

7. The method for growing graphene in situ on the surface of a plasma alloying contact by laser according to claim 1 is applied to preparing in situ growth graphene/alloying metal contact materials.

8. The use of the graphene/alloyed metal contact material prepared by the method for growing graphene in situ on the surface of a plasma alloyed contact by laser according to claim 1 in a high voltage direct current air switch.

Technical Field

The invention belongs to the technical field of high-voltage electrical equipment, and particularly relates to a method for in-situ growth of graphene on the surface of a plasma alloying metal contact material based on laser heating and application thereof.

Background

The electric contact is a contact element of an electric switch, an instrument assembly and the like, and has the functions of loading current, switching on and switching off the current and the like. The performance and service condition of the contact material directly determine the starting capability, contact safety, reliability and the like of the electrical switch, and further influence the actual working condition and service life of a power distribution system. The lower end of a switch device of a rail transit traction power system is loaded on a large traction unit with the load of hundreds of kilowatts, and the contact material of a key part of the large traction unit faces huge challenges of high arc breaking difficulty, serious arc ablation and the like. The air direct current switch adopted by large-scale traction units in subways and high-speed rails has the advantages that the stability of electric arcs is enhanced due to the volt-ampere characteristics of the direct current switch, and the electric arcs and the current after being turned off generate joule heat, so that ablation, fusion welding and evaporation of contact materials are easily caused. And the ablation damage of the electric arc to the contact can cause the failure of the electric switch, thereby influencing the stable operation of traction units such as high-speed rails, subways and the like. Therefore, the development of a novel composite electrical contact material resistant to arc ablation is of great benefit to the development of the high-voltage electrical industry in China.

In a high-voltage distribution system, the contact material is mainly copper-based alloy. Copper has high electrical conductivity and high thermal conductivity, but has the defects of high melting point, high Young modulus and the like. The alloying method can improve the mechanical property of the copper-based contact, but simultaneously can sacrifice the excellent electric conduction and heat conduction properties of part of copper. And graphene is used as a new material, and the ultrahigh Young modulus, electric conductivity and thermal conductivity of the graphene provide a feasible solution for simultaneously meeting the mechanical, heat conduction and electric conductivity of the copper-based contact material.

Graphene can be grown in situ on the surface of the alloyed metal contact substrate by designing a specific alloy system. The plasma alloying method can improve the bonding strength between the metal substrate and the graphene film, and simultaneously well utilizes the excellent mechanical strength and corrosion resistance of the graphene. According to the method for in-situ growth of graphene on the surface of the alloyed metal contact material by laser heating, disclosed by the invention, the nickel/metal contact material is prepared by a plasma jet spray process, then a solid carbon source is spin-coated on the nickel metal contact material, and then the graphene is grown by laser heating. The graphene is taken as an independent coating to completely cover the surface of the alloying contact material and is directly taken as a coating to deal with ablation, fusion welding and evaporation of the contact material. On the one hand, the graphene film generated in situ does not need to be transferred or combined with a metal substrate through spin coating, so that the bonding strength between the graphene and the metal substrate is greatly enhanced, and on the other hand, the graphene film can be generated on the metal surface conveniently and rapidly in a large area, so that the production efficiency is improved, the ablation resistance of the contact material is greatly improved, and the service life of the contact material is greatly prolonged.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a method for in-situ growth of graphene on the surface of a plasma alloying contact by laser, which adopts a plasma alloying means to prepare an alloying contact material and then adopts laser to heat an in-situ growth graphene film.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for in-situ growth of graphene on the surface of a plasma alloying contact by laser is characterized in that,

s1, preparing required raw material components according to target components, introducing metallic nickel by adopting a plasma alloying process, wherein in the alloying process, the current is 100-200A, the arc striking height of a plasma gun is 2.5-3.5 mm, the scanning speed is 200-500 mm/min, the feeding rate is 15-30 g/min, a nickel/metal material melt is subjected to multilayer reciprocating jet deposition under the protection action of protective gas, the thickness of each layer is 1.5-2.0 mm, the nickel/metal material melt is subjected to jet deposition on a substrate under the carrying action of ionic gas and the protective gas, and finally the nickel/copper contact material is prepared by plasma alloying;

s2, pre-coating a solid carbon source on the surface of the nickel/copper contact material, and then heating by using laser to realize in-situ growth of graphene; the laser power is 2000-6000W, the spot diameter is 50-500 μm, the laser power is 1500-5500W, and the scanning speed is 1-50 mm/s.

Further, in step S1, the particle diameters of the metal nickel and copper are 1 to 100 μm.

Further, in step S1, the contact material includes a copper oxide alloy, a copper nickel alloy, a copper carbon alloy, a copper tungsten alloy, and/or a copper tungsten carbon alloy.

Further, in step S2, in the process of implementing in-situ graphene growth by laser heating, the laser adopts fiber laser and CO₂Laser or semiconductor laser.

Further, in step S2, the solid carbon source is graphite powder, and the thickness of the pre-layer is 5 to 50 μm.

Further, in step S2, the particle size of the graphite powder is 30-100 nm.

And further, preparing the in-situ growth graphene/alloying metal contact material.

Further, the prepared graphene/alloyed metal contact material is applied to a high-voltage direct-current air switch.

The invention has the beneficial effects that:

the invention provides a method for growing graphene on the surface of a plasma alloying metal contact material in situ by using laser heating, which fully exerts the excellent properties of high strength, ablation resistance and ultrahigh Young modulus of a full-coverage graphene film, is tightly combined with a metal substrate and has the characteristic of zero friction, so that the graphene film has ultrahigh friction resistance, provides reliable ablation resistance and wear resistance for metal, and can greatly improve the service performance and service life of the contact material.

Furthermore, micron-sized nickel powder and copper powder can be better fused by utilizing a plasma spraying process, the components are more uniform, and high-quality alloying contact materials can be obtained.

Furthermore, the copper alloy commonly used in the high-voltage field is the set 5-class copper alloy, and the invention can improve the service performance of the copper-based contact material commonly used in the market at present.

Furthermore, the working gas is also used as a powder spraying carrier gas, and the working gas can deoxidize and degas the nickel/metal alloy.

Furthermore, the nickel/metal material melt can be quickly formed within the set plasma alloying parameter range.

Furthermore, the thickness and the particle size of the set graphite powder can completely cover the surface of the alloying contact material, so that a compact graphene film can be formed.

Furthermore, the set laser heating parameters can be efficient, a compact graphene film can be grown on the surface of the contact material in a large area, and secondary transfer of the graphene film is avoided.

In conclusion, the method for in-situ growth of graphene by using the plasma alloying contact material fully exerts the excellent electrical, thermal and mechanical properties of graphene, so that the copper-based alloy contact material has high thermal conductivity, high mechanical property, arc ablation resistance and friction resistance.

Drawings

Fig. 1 is a schematic diagram of plasma alloying and laser heating for preparing graphene, wherein (a) is a schematic diagram of a plasma alloying process; (b) is a schematic diagram of laser heating in-situ preparation of graphene;

FIG. 2 is a plasma alloyed coating and a cross-sectional view;

fig. 3 shows the result of graphene characterization, wherein (a) is an optical microscope picture; (b) graphene raman spectroscopy.

Detailed Description

The invention is further described with reference to the following figures and examples.

A method for in-situ growth of graphene on the surface of a plasma alloying contact by laser is characterized in that,

s1, preparing required raw material components according to target components, introducing metallic nickel by adopting a plasma alloying process, wherein in the alloying process, the current is 100-200A, the arc striking height of a plasma gun is 2.5-3.5 mm, the scanning speed is 200-500 mm/min, the feeding rate is 15-30 g/min, a nickel/metal material melt is subjected to multilayer reciprocating jet deposition under the protection action of protective gas, the thickness of each layer is 1.5-2.0 mm, the nickel/metal material melt is subjected to jet deposition on a substrate under the carrying action of ionic gas and the protective gas, and finally the nickel/copper contact material is prepared by plasma alloying;

s2, pre-coating a solid carbon source on the surface of the nickel/copper contact material, and then heating by using laser to realize in-situ growth of graphene; the laser power is 2000-6000W, the spot diameter is 50-500 μm, the laser power is 1500-5500W, and the scanning speed is 1-50 mm/s.

Further, in step S1, the particle diameters of the metal nickel and copper are 1 to 100 μm.

Further, in step S1, the contact material includes a copper oxide alloy, a copper nickel alloy, a copper carbon alloy, a copper tungsten alloy, and/or a copper tungsten carbon alloy.

Further, in step S2, in the process of implementing in-situ graphene growth by laser heating, the laser adopts fiber laser and CO₂Laser or semiconductor laser.

Further, in step S2, the solid carbon source is graphite powder, and the thickness of the pre-layer is 5 to 50 μm.

Further, in step S2, the particle size of the graphite powder is 30-100 nm.

And further, preparing the in-situ growth graphene/alloying metal contact material.

Further, the prepared graphene/alloyed metal contact material is applied to a high-voltage direct-current air switch.

Example 1

Preparing an alloyed Cu/Ni contact material by utilizing plasma spraying, and preparing graphene on the surface of the alloyed Cu/Ni contact material in situ by adopting semiconductor laser.

The preparation steps are as follows:

(1) plasma alloying Cu/Ni contact material

The alloyed Ni/Cu contact material is prepared by a plasma jet process. The plasma alloying process parameters are as follows: the current is 100-200A, the arc starting height of the plasma gun is 2.5-3.5 mm, the scanning speed is 200-500 mm/min, and the feeding speed is 15-30 g/min. The process is shown in figure 1 (a). FIG. 2 shows the surface topography and cross-section of an alloyed layer.

(2) Semiconductor laser heating in-situ growth graphene

Using high power connectionsIrradiating continuous semiconductor laser (with wavelength of 1080nm and maximum power of 6000W) on the surface of alloyed Cu/Ni contact material preset with 5 μm graphite powder, wherein the size of the alloyed contact material is 50 × 50 × 5mm³. The laser process parameters are as follows: spot diameter of 60 μm and power density of 1 × 10³ W/cm²And the scanning speed is 10 mm/s. See FIG. 1 (b). The morphology and structure of graphene are shown in figure 3.

Example 2

Preparing alloyed Cu/Ni contact material by plasma spraying, and adopting CO₂And preparing graphene on the surface of the alloyed Cu/Ni contact material in situ by laser.

The preparation steps are as follows:

(1) plasma alloying Cu/Ni contact material

The alloyed Cu/Ni contact material is prepared by a plasma jet process. The plasma alloying process parameters are as follows: the current is 100-200A, the arc starting height of the plasma gun is 2.5-3.5 mm, the scanning speed is 200-500 mm/min, and the feeding speed is 15-30 g/min.

(2)CO₂Laser heating in-situ growth graphene

Using high power continuous CO₂Irradiating laser (wavelength of 900nm and maximum power of 10000W) on the surface of alloyed Cu/Ni contact material preset with 5 μm graphite powder, wherein the size of the alloyed contact material is 50 × 50 × 5mm³. The laser process parameters are as follows: spot diameter of 30 μm and power density of 10 × 10³W/cm²And the scanning speed is 100 mm/s.

Example 3

Preparing an alloyed Cu/C contact material by utilizing plasma jet, and preparing graphene on the surface of the alloyed Cu/C contact material in situ by adopting semiconductor laser, wherein the preparation steps are as follows:

(1) plasma alloying Cu/C contact material

And preparing the alloyed Cu/C contact material by a plasma jet process. The plasma alloying process parameters are as follows: the current is 100-200A, the arc starting height of the plasma gun is 2.5-3.5 mm, the scanning speed is 200-500 mm/min, and the feeding speed is 15-30 g/min.

(2) Semiconductor laser heating in-situ growth graphene

Irradiating the surface of alloyed Cu/C contact material preset with 5 μm graphite powder with high-power continuous semiconductor laser (with wavelength of 1080nm and maximum power of 6000W), wherein the size of the alloyed contact material is 50 × 50 × 5mm³. The laser process parameters are as follows: spot diameter of 60 μm and power density of 10 × 10³W/cm²And the scanning speed is 100 mm/s. See FIG. 1 (b).

Example 4

The preparation method comprises the following steps of preparing an alloyed Cu/C contact material by plasma jet, and preparing graphene on the surface of the alloyed Cu/C contact material in situ by adopting fiber laser:

the preparation steps are as follows:

(1) plasma alloying Cu/C contact material

And preparing the alloyed Cu/C contact material by a plasma jet process. The plasma alloying process parameters are as follows: the current is 100-200A, the arc starting height of the plasma gun is 2.5-3.5 mm, the scanning speed is 200-500 mm/min, and the feeding speed is 15-30 g/min.

(2) Optical fiber laser heating in-situ growth graphene

Irradiating the surface of an alloyed Cu/C contact material preset with 5 mu m graphite powder by using high-power continuous fiber laser (the wavelength is 1060nm, the maximum power is 5000W), wherein the size of the alloyed contact material is 50 multiplied by 5mm³. The laser process parameters are as follows: spot diameter of 40 μm and power density of 2X 10³W/cm²And the scanning speed is 20 mm/s.

Example 5

Preparing an alloyed Cu/W contact material by utilizing plasma spraying, and preparing graphene on the surface of the alloyed Cu/W contact material in situ by adopting fiber laser, wherein the preparation steps are as follows:

the preparation steps are as follows:

(1) plasma alloying Cu/W contact material

And preparing the alloyed Cu/W contact material by a plasma jet process. The plasma alloying process parameters are as follows: the current is 100-200A, the arc starting height of the plasma gun is 2.5-3.5 mm, the scanning speed is 200-500 mm/min, and the feeding speed is 15-30 g/min.

(2) Optical fiber laser heating in-situ growth graphene

Irradiating the surface of an alloyed Cu/W contact material preset with 5 mu m graphite powder by using high-power continuous fiber laser (the wavelength is 1060nm, the maximum power is 5000W), wherein the size of the alloyed contact material is 50 multiplied by 5mm³. The laser process parameters are as follows: spot diameter of 50 μm and power density of 7X 10³W/cm²And the scanning speed is 30 mm/s. See FIG. 1 (b).

Example 6

Preparing an alloyed Cu/C/W contact material by utilizing plasma jet, and preparing graphene on the surface of the alloyed Cu/C/W contact material in situ by adopting semiconductor laser, wherein the preparation steps are as follows:

the preparation steps are as follows:

(1) plasma alloying Cu/C/W contact material

And preparing the alloyed Cu/C/W contact material by a plasma jet process. The plasma alloying process parameters are as follows: the current is 100-200A, the arc starting height of the plasma gun is 2.5-3.5 mm, the scanning speed is 200-500 mm/min, and the feeding speed is 15-30 g/min.

(2) Optical fiber laser heating in-situ growth graphene

Irradiating the surface of alloyed Cu/C/W contact material preset with 5 μm graphite powder with high-power continuous semiconductor laser (with wavelength of 1080nm and maximum power of 6000W), wherein the size of the alloyed contact material is 50 × 50 × 5mm³. The laser process parameters are as follows: the spot diameter was 40 μm, the power density was 5X 103W/cm2, and the scanning speed was 50 mm/s.

In summary, in the graphene/metal-based composite contact material designed by the invention, the graphene is used as an independent coating to completely cover the surface of the copper-based alloy, and directly undertakes the damages such as arc ablation, current joule heat, mechanical friction/fatigue and the like. Meanwhile, the nickel element is added into the substrate, so that the nickel element can be used as a catalyst for graphene growth on one hand, and the mechanical property of the copper-based alloy can be improved on the other hand.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.