Graphene / metal wear-resistant material based on laser and CVD composite process and preparation method and application thereof

Abstract

This invention discloses a graphene / metal wear-resistant material based on a laser and CVD composite process, its preparation method, and its application, belonging to the field of friction and wear resistance technology. The method involves in-situ pre-growth of graphene seed crystals on a metal substrate surface via laser alloying, followed by graphene growth using chemical vapor deposition (CVD) to obtain the graphene / metal wear-resistant material. In this method, the pre-growth of graphene seed crystals via laser in-situ growth creates a metallurgical bond between the graphene film and the metal substrate. This tight bond between the graphene film and the metal substrate improves the material's friction and wear resistance. Furthermore, the use of CVD for large-area graphene growth based on the laser-pre-grown graphene seed crystals overcomes the limitation of laser-based large-area growth, resulting in a thicker graphene film. This further enhances the friction and wear resistance of the metal material, extending the service life and safety of the graphene / metal wear-resistant material.

Description

Technical Field

[0001] This invention belongs to the field of friction and wear resistance, specifically relating to a graphene / metal wear-resistant material based on laser and CVD composite process, its preparation method and application. Background Technology

[0002] Friction and wear are ubiquitous in daily life, and the friction and wear between materials often lead to energy and economic losses. In modern industry, friction and wear have always been one of the main causes of mechanical equipment failure and material failure. Due to the friction and wear of mechanical parts, metal components are damaged. The most common methods to solve this problem are adding protective layers, using lubricants, and composite materials. Among these, the most effective method is to add a protective layer to the metal surface to reduce friction, thereby protecting the metal material. Graphene, due to its excellent mechanical properties, extremely low coefficient of friction, good mechanical properties, chemical stability, and low environmental pollution, can be used as a solid lubricant to form a protective layer on the metal surface to reduce friction, thus having a very broad application prospect in the field of metal protection.

[0003] Graphene, with its high strength and extremely low coefficient of friction, offers a new approach to improving the friction-reducing and wear-resistant properties of materials. Currently, the most common method for growing graphene on metal surfaces is chemical vapor deposition (CVD). This method can grow large-area graphene films on metal surfaces of any size. However, its drawbacks include poor adhesion between the grown graphene film and the substrate, thin film thickness, long processing time, and the involvement of flammable and explosive gases. Liquid-phase methods for preparing graphene films also suffer from insufficient adhesion, failing to provide lasting protection to the metal. Therefore, there is an urgent need to develop an efficient and low-cost method for growing high-adhesion, large-area, high-quality, and relatively thick graphene films on metal surfaces. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a graphene / metal wear-resistant material based on laser and CVD composite process, its preparation method and application, so as to solve the technical problems that the graphene film prepared by the existing method is thin, the bonding strength with the metal substrate is insufficient, and it is prone to wear and failure due to physical friction and changes in the service environment during service.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] This invention discloses a method for preparing graphene / metal wear-resistant materials based on a laser and CVD composite process. A solid carbon source is pre-placed on the surface of a metal substrate. Under a protective atmosphere, graphene seed crystals are pre-grown on the surface of the metal substrate by laser alloying. Then, graphene is grown by chemical vapor deposition to obtain the graphene / metal wear-resistant material.

[0007] Preferably, the metal matrix includes nickel-based high-temperature alloys, high-temperature titanium alloys, stainless steel, copper alloys, and aluminum alloys.

[0008] More preferably, the nickel-based superalloys include Inconel 600, Inconel 601, Inconel 625, Inconel 718, Inconel X750 and Incoloy 800, the high-temperature titanium alloys include TC4, TC6 and Ti811, and the aluminum alloys include 2A16, 2A17 and 2219.

[0009] Preferably, the solid carbon source includes nano-carbon powder, pencil lead, and solid polystyrene.

[0010] Preferably, the particle size of the solid carbon source is 20–100 nm, and the thickness of the pre-formed layer is 5–100 μm.

[0011] Preferably, the protective atmosphere is argon or nitrogen, with a flow rate of 50–400 g / min.

[0012] Preferably, the laser alloying process uses a nanosecond pulsed laser, fiber laser, CO2 laser, or semiconductor laser, with a maximum power of 10–500W.

[0013] Preferably, the parameters of the laser alloying process are: 1 to 10 processing times, spot diameter 40 to 100 μm, laser power 10 to 500 W, laser frequency 30 to 500 kHz, scanning speed 5 to 600 mm / s, and pulse width 50 to 350 ns.

[0014] Preferably, the parameters of the chemical vapor deposition method are: a holding temperature of 1000-1200℃, a gas ratio of Ar:H2:CH4 = 30:5:(1-12), a gaseous carbon source introduction time of 5-60 min, a heating rate of 10℃ / min, and a cooling rate of 5℃ / min.

[0015] Preferably, the gaseous carbon source includes methane, acetylene, propane, and petroleum gas.

[0016] The present invention also discloses a graphene / metal wear-resistant material prepared by the above preparation method.

[0017] The present invention also discloses the application of the above-mentioned graphene / metal wear-resistant material in the field of metal protection.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention discloses a method for preparing graphene / metal wear-resistant materials based on a laser and CVD composite process. First, a solid carbon source is pre-placed on the surface of a metal substrate to provide carbon atoms for graphene growth. Then, the surface of the metal substrate with the pre-placed solid carbon source is irradiated using a laser alloying process to pre-grow graphene seed crystals in situ. The purpose is to immediately generate graphene seed crystals with metallurgical bonding to the substrate in the irradiated area after the laser is turned off. Next, graphene is grown over a large area using chemical vapor deposition (CVD). CVD overcomes the limitation of laser technology in large-area graphene growth and yields thicker, higher-quality, and more tightly bonded graphene films. It is an efficient graphene growth method, ultimately producing a graphene film with strong substrate-film bonding, large area, high quality, uniform density, and multiple layers, providing durable and effective protection and performance enhancement for the substrate. By designing a specific graphene growth process—a composite process of laser alloying and chemical vapor deposition—the following advantages are achieved: First, graphene can be grown on the surface of a metal substrate. The graphene acts as an independent coating, completely covering the metal substrate surface. This enhances the adhesion between the graphene film and the metal substrate while fully utilizing graphene's extremely low coefficient of friction and excellent chemical stability to combat damage caused by mechanical friction and wear. Second, the prepared graphene film exhibits a metallurgical bond with the metal substrate, resulting in a strong and robust bond. The contact surface is composed of a graphene film with high mechanical strength and an extremely low coefficient of friction, giving the metal material better friction and wear resistance and improved mechanical strength. Third, the graphene film prepared by laser alloying does not require transfer or spin-coating to bond with the substrate, significantly enhancing the integrity of the graphene film and the bonding strength between the graphene film and the substrate. Fourth, chemical vapor deposition (CVD) allows for the convenient and rapid large-area growth of graphene on metal surfaces pre-grown with graphene seed crystals, overcoming the limitation of laser growth in large areas. This improves production efficiency, making the graphene film an effective barrier to prevent metal failure due to friction, significantly enhancing the friction and wear resistance of the metal substrate, reducing economic losses caused by performance failures, and providing new ideas for the application of graphene in friction and wear resistance. Fifth, CVD enables large-area, controllable growth on metal surfaces pre-grown with graphene seed crystals. Epitaxial growth based on carbon atoms obtained from laser pre-growth yields graphene films with strong substrate adhesion, large area, high quality, uniform density, and considerable thickness, providing a durable guarantee for improving the friction and wear resistance of metal materials. Sixth, it fully leverages the excellent properties of graphene's extremely low coefficient of friction and its tight bond with the metal substrate, giving it extremely high anti-friction capabilities. This provides the substrate with reliable strength, wear resistance, and chemical stability, which can greatly improve the service life and safety of graphene / metal wear-resistant materials and reduce the huge economic losses and safety accident rates caused by high coefficient of friction and high wear rate.Therefore, the graphene / metal material obtained by this method can overcome the shortcomings of existing materials, such as weak interfacial bonding and insufficient graphene for lubrication, which cannot meet the corresponding requirements of wear-resistant materials and thus cause damage. It can greatly extend the service life of metal materials and improve their friction and wear resistance, providing theoretical basis and empirical guidance for solving the current drawbacks of graphene in the field of friction.

[0020] Furthermore, the selected solid carbon source particle size allows for easier dissolution into the matrix, resulting in higher supersaturated solid solubility and providing a carbon source for graphene growth. The thickness of the laser-grown graphene seed crystals can be precisely controlled by adjusting the thickness of the solid carbon source coating and the laser parameters, making it a stable and controllable preparation method.

[0021] Furthermore, high-power continuous lasers can heat an alloy substrate to its own melting point in a short time, forming a molten pool, which is a highly efficient thermal processing method.

[0022] The present invention also discloses a graphene / metal wear-resistant material prepared by the above preparation method. This graphene / metal wear-resistant material fully utilizes the extremely low coefficient of friction of graphene, enabling the graphene / metal material to simultaneously possess good mechanical strength, chemical stability, and wear resistance, thereby improving the safety of metal materials during service and ultimately achieving the goal of reducing processing costs and extending the service life of metal workpieces and equipment. This represents a substantial step forward in the application of graphene in the field of metal protection.

[0023] The present invention also discloses the application of the above-mentioned graphene / metal material in metal protection. When applied, the material has a long service life and high safety, and can reduce the huge economic losses and safety accident rate caused by high friction coefficient, high wear rate and poor chemical stability. Attached Figure Description

[0024] Figure 1 The optical microscopy image and Raman characterization image of the laser-pre-grown graphene seed crystal are shown in Example 12 of the present invention. (a) is the optical microscopy image of the laser-irradiated pre-grown graphene seed crystal, and (b) is the Raman characterization image of the laser-irradiated pre-grown graphene seed crystal.

[0025] Figure 2 The images shown are optical micrographs and Raman spectroscopy images of graphene grown by chemical vapor deposition after laser pre-growth of graphene seed crystals in Example 12 of this invention. In particular, (c) is an optical micrograph of graphene grown by chemical vapor deposition, and (d) is a Raman spectroscopy image of graphene grown by chemical vapor deposition.

[0026] Figure 3 The curve showing the change in friction coefficient over time for the graphene / metal wear-resistant material prepared in this invention. Detailed Implementation

[0027] To enable those skilled in the art to understand the features and effects of the present invention, the following descriptions and definitions are only general descriptions of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in the event of any conflict, the definitions in this specification shall prevail.

[0028] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0029] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0030] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0031] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0032] This invention discloses a method for preparing graphene / metal wear-resistant materials based on a laser and CVD composite process. First, a solid carbon source is pre-placed on the surface of a metal substrate. Then, graphene seed crystals are pre-grown in situ by laser irradiation of the sample surface. Finally, graphene is further grown using chemical vapor deposition. The specific steps include:

[0033] S1. A solid carbon source with a particle size of 20-100 nm is pre-placed on the surface of a metal substrate, and the pre-placed layer thickness is 5-100 μm. Then, under a protective atmosphere, the surface of the metal substrate is irradiated with a laser to perform in-situ pre-growth of graphene seed crystals.

[0034] The metals mentioned include, but are not limited to, nickel-based superalloys (Inconel 600, Inconel 601, Inconel 625, Inconel 718, Inconel X750, or Incoloy 800), high-temperature titanium alloys (TC4, TC6, or Ti811), aluminum alloys (2A16, 2A17, or 2219), copper alloys, and stainless steel. The solid carbon sources mentioned include, but are not limited to, graphite powder, pencil lead, and polystyrene. The protective atmosphere includes, but is not limited to, argon or nitrogen, with a flow rate of 50–400 g / min. The method for in-situ laser pre-growth of graphene seed crystals is a laser alloying process, which uses a nanosecond pulsed laser, CO2 laser, fiber laser or semiconductor laser with a maximum power of 10-500W. The laser alloying process parameters are: 1-10 processing times, spot diameter of 40-100μm, scanning speed of 5-600mm / s, laser frequency of 30-500KHz, laser power of 10-500W, and pulse width of 50-350ns.

[0035] S2. Graphene films are grown by chemical vapor deposition to prepare graphene / metal wear-resistant materials.

[0036] The chemical vapor deposition method is wherein the holding temperature is 1000-1200℃, the gas ratio is Ar:H2:CH4=30:5:(1-12), the gaseous carbon source (methane, acetylene, propane or petroleum gas) is introduced for 5-60 min, the heating rate is 10℃ / min, and the cooling rate is 5℃ / min.

[0037] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0038] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0039] Example 1

[0040] In-situ pre-growth of graphene seed crystals was performed on 2A16 aluminum alloy using a semiconductor with a maximum power of 50W, and then graphene was grown on this basis using chemical vapor deposition.

[0041] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0042] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0043] Nano-carbon powder was uniformly dispersed in an ethanol solution and coated onto a 2A16 aluminum alloy substrate using a spin-coating method to provide the necessary carbon atoms for graphene growth. After drying, the sample was placed in the vacuum chamber of a laser processor to prevent oxidation during the experiment.

[0044] A semiconductor laser (maximum power 50W) was used to irradiate the surface of a 2A16 aluminum alloy substrate in an argon atmosphere. The gas flow rate was 200 g / min, and the irradiation area was 80 mm × 80 mm. The laser process parameters were: spot diameter 50 μm, processing times 5, laser scanning speed 200 mm / s, laser power 25 W, laser frequency 280 kHz, pulse width 350 ns, and width of each scanning track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0045] (2) Graphene growth by chemical vapor deposition

[0046] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1150℃, the gas ratio was Ar:H2:CH4=30:5:2, the gaseous carbon source was introduced for 10 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0047] Example 2

[0048] In-situ pre-growth of graphene seed crystals was carried out on Inconel 601 alloy using a nanosecond pulsed laser with a maximum power of 10W, and then graphene was grown on this basis using chemical vapor deposition.

[0049] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0050] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0051] Nano-carbon powder was uniformly dispersed in an ethanol solution and coated onto an Inconel 601 alloy substrate using a spin-coating method to provide the necessary carbon atoms for graphene growth. After drying, the sample was placed in the vacuum chamber of a laser processor to prevent oxidation during the experiment.

[0052] In an argon atmosphere, a nanosecond pulsed laser (maximum power 10W) ​​was used to irradiate the surface of an Inconel 601 alloy substrate. The gas flow rate was 50 g / min, and the irradiated area was 15 mm × 15 mm. The laser process parameters were: spot diameter 55 μm, number of passes 8, laser scanning speed 350 mm / s, laser power 18W, laser frequency 30 kHz, pulse width 150 ns, and width of each scan track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0053] (2) Graphene growth by chemical vapor deposition

[0054] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1050℃, the gas ratio was Ar:H2:CH4 = 30:5:5, the gaseous carbon source was introduced for 25 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0055] Example 3

[0056] Graphene seed crystals were pre-grown in situ on TC4 alloy using a fiber laser with a maximum power of 450W, and then graphene was grown using chemical vapor deposition.

[0057] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0058] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0059] A uniform layer of pencil lead was pre-coated on the surface of the TC4 alloy substrate to provide the carbon atoms required for graphene growth. The substrate was then placed in the vacuum chamber of the laser processor to prevent the sample from oxidizing during the experiment.

[0060] A fiber laser (maximum power 450W) was used to irradiate the surface of a TC4 alloy substrate under a nitrogen atmosphere. The gas flow rate was 250 g / min, and the irradiation area was 10 mm × 10 mm. The laser process parameters were: spot diameter 60 μm, processing times 1, laser scanning speed 400 mm / s, laser power 350 W, laser frequency 500 kHz, pulse width 350 ns, and width of each scanning track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0061] (2) Graphene growth by chemical vapor deposition

[0062] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1200℃, the gas ratio was Ar:H2:CH4=30:5:10, the gaseous carbon source was introduced for 50 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0063] Example 4

[0064] In-situ pre-growth of graphene seed crystals was carried out on Inconel 625 alloy using a nanosecond pulsed laser with a maximum power of 200W, and then graphene was grown on this basis using chemical vapor deposition.

[0065] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0066] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0067] A uniform layer of pencil lead is pre-coated onto the surface of the Inconel 625 alloy substrate to provide the necessary carbon atoms for graphene growth. The substrate is then placed in the vacuum chamber of the laser processor to prevent oxidation of the sample during the experiment.

[0068] In an argon atmosphere, a nanosecond pulsed laser (maximum power 200W) was used to irradiate the surface of an Inconel 625 alloy substrate. The gas flow rate was 400 g / min, and the irradiation area was 30 mm × 30 mm. The laser process parameters were: spot diameter 40 μm, number of passes 10, laser scanning speed 600 mm / s, laser power 200W, laser frequency 100 kHz, pulse width 300 ns, and width of each scan track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0069] (2) Graphene growth by chemical vapor deposition

[0070] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1000℃, the gas ratio was Ar:H2:CH4 = 30:5:4, the gaseous carbon source was introduced for 20 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0071] Example 5

[0072] In-situ pre-growth of graphene seed crystals was carried out on 2219 aluminum alloy using a CO2 laser with a maximum power of 500W, and then graphene was grown on this basis using chemical vapor deposition.

[0073] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0074] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0075] Solid polystyrene was uniformly coated onto the surface of a 2219 aluminum alloy substrate to provide the necessary carbon atoms for graphene growth. The substrate was then placed in the vacuum chamber of a laser processor to prevent oxidation of the sample during the experiment.

[0076] A CO2 laser (maximum power 500W) was used to irradiate the surface of a 2219 aluminum alloy substrate in an argon atmosphere. The gas flow rate was 50 g / min, and the irradiated area was 5 mm × 5 mm. The laser process parameters were: spot diameter 65 μm, number of passes 7, laser scanning speed 100 mm / s, laser power 220W, laser frequency 180 kHz, pulse width 80 ns, and width of each scan track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0077] (2) Graphene growth by chemical vapor deposition

[0078] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1180℃, the gas ratio was Ar:H2:CH4=30:5:1, the gaseous carbon source was introduced for 5 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0079] Example 6

[0080] In-situ pre-growth of graphene seed crystals on 2A16 aluminum alloy was carried out using a semiconductor laser with a maximum power of 250W, and then graphene was grown on this basis using chemical vapor deposition.

[0081] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0082] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0083] Solid polystyrene was uniformly coated onto the surface of a 2A16 aluminum alloy substrate to provide the necessary carbon atoms for graphene growth. The substrate was then placed in the vacuum chamber of a laser processor to prevent oxidation of the sample during the experiment.

[0084] In an argon atmosphere, a semiconductor laser (maximum power 250W) was used to irradiate the surface of a 2A16 aluminum alloy substrate. The gas flow rate was 160 g / min, and the irradiation area was 20 mm × 20 mm. The laser process parameters were: spot diameter 70 μm, processing times 10, laser scanning speed 280 mm / s, laser power 330 W, laser frequency 120 kHz, pulse width 150 ns, and width of each scanning track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0085] (2) Graphene growth by chemical vapor deposition

[0086] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1080℃, the gas ratio was Ar:H2:CH4=30:5:6, the gaseous carbon source was introduced for 30 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0087] Example 7

[0088] In-situ pre-growth of graphene seed crystals on Inconel 718 alloy was carried out using a nanosecond pulsed laser with a maximum power of 400W, and then graphene was grown on this basis using chemical vapor deposition.

[0089] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0090] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0091] Nano-carbon powder was uniformly dispersed in an ethanol solution and coated onto an Inconel 718 alloy substrate using a spin-coating method to provide the necessary carbon atoms for graphene growth. After drying, the sample was placed in the vacuum chamber of a laser processor to prevent oxidation during the experiment.

[0092] In a nitrogen atmosphere, a nanosecond pulsed laser (maximum power 400W) was used to irradiate the surface of an Inconel 718 alloy substrate. The gas flow rate was 260 g / min, and the irradiated area was 30 mm × 30 mm. The laser process parameters were: spot diameter 75 μm, number of passes 4, laser scanning speed 80 mm / s, laser power 300W, laser frequency 450 kHz, pulse width 50 ns, and width of each scan track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0093] (2) Graphene growth by chemical vapor deposition

[0094] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1010℃, the gas ratio was Ar:H2:CH4=30:5:11, the gaseous carbon source was introduced for 55 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0095] Example 8

[0096] In-situ pre-growth of graphene seed crystals on Inconel X750 alloy was carried out using a fiber laser with a maximum power of 250W, and then graphene was grown on this basis using chemical vapor deposition.

[0097] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0098] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0099] Nano-carbon powder was uniformly dispersed in an ethanol solution and then coated onto an Inconel X750 alloy substrate using a spin-coating method to provide the necessary carbon atoms for graphene growth. After drying, the sample was placed in the vacuum chamber of a laser processor to prevent oxidation during the experiment.

[0100] In a nitrogen atmosphere, an Inconel X750 alloy substrate was irradiated with a fiber laser (maximum power 250W) at a gas flow rate of 320 g / min, covering an area of ​​40 mm × 40 mm. The laser process parameters were: spot diameter 80 μm, 9 passes, laser scanning speed 35 mm / s, laser power 100 W, laser frequency 50 kHz, pulse width 230 ns, and 1 mm width for each scan track. This process achieved in-situ pre-growth of graphene seed crystals on the substrate surface.

[0101] (2) Graphene growth by chemical vapor deposition

[0102] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1110℃, the gas ratio was Ar:H2:CH4=30:5:12, the gaseous carbon source was introduced for 60 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0103] Example 9

[0104] In-situ pre-growth of graphene seed crystals was performed on TC6 alloy using a CO2 laser with a maximum power of 80W, and then graphene was grown using chemical vapor deposition.

[0105] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0106] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0107] Pencil lead was pre-coated onto the surface of the TC6 alloy substrate to provide the necessary carbon atoms for graphene growth. The substrate was then placed in the vacuum chamber of the laser processor to prevent oxidation of the sample during the experiment.

[0108] A CO2 laser (maximum power 80W) was used to irradiate the surface of a TC6 alloy substrate under a nitrogen atmosphere. The gas flow rate was 380 g / min, and the irradiated area was 35 mm × 35 mm. The laser process parameters were: spot diameter 85 μm, processing times 3, laser scanning speed 120 mm / s, laser power 320 W, laser frequency 270 kHz, pulse width 320 ns, and width of each scanning track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0109] (2) Graphene growth by chemical vapor deposition

[0110] The product after laser pre-growth of graphene seed crystals was placed in a nitrogen atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1130℃, the gas ratio was Ar:H2:CH4=30:5:1, the gaseous carbon source was introduced for 5 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0111] Example 10

[0112] In-situ pre-growth of graphene seed crystals was carried out on 2A17 alloy using a semiconductor laser with a maximum power of 150W, and then graphene was grown using chemical vapor deposition.

[0113] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0114] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0115] Pencil lead was pre-coated onto the surface of a 2A17 alloy substrate to provide the necessary carbon atoms for graphene growth. The substrate was then placed in the vacuum chamber of a laser processor to prevent oxidation of the sample during the experiment.

[0116] In a nitrogen atmosphere, a semiconductor laser (maximum power 150W) was used to irradiate the surface of a 2A17 alloy substrate. The gas flow rate was 100g / min, and the irradiated area was 23mm × 23mm. The laser process parameters were: spot diameter 90μm, number of passes 6, laser scanning speed 50mm / s, laser power 100W, laser frequency 50kHz, pulse width 110ns, and width of each scan track 1mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0117] (2) Graphene growth by chemical vapor deposition

[0118] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1070℃, the gas ratio was Ar:H2:CH4=30:5:10, the gaseous carbon source was introduced for 50 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0119] Example 11

[0120] Graphene seed crystals were pre-grown in situ on Incoloy 800 alloy using a fiber laser with a maximum power of 100W, and then graphene was grown using chemical vapor deposition.

[0121] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0122] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0123] Solid polystyrene was uniformly coated onto the surface of an Incoloy 800 alloy substrate to provide the necessary carbon atoms for graphene growth. The substrate was then placed in the vacuum chamber of a laser processor to prevent oxidation of the sample during the experiment.

[0124] In a nitrogen atmosphere, a fiber laser (maximum power 100W) was used to irradiate the surface of an Incoloy 800 alloy substrate. The gas flow rate was 330 g / min, and the irradiation area was 60 mm × 60 mm. The laser process parameters were: spot diameter 100 μm, number of passes 2, laser scanning speed 530 mm / s, laser power 420 W, laser frequency 60 kHz, pulse width 140 ns, and width of each scan track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0125] (2) Graphene growth by chemical vapor deposition

[0126] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1030℃, the gas ratio was Ar:H2:CH4=30:5:5, the gaseous carbon source was introduced for 25 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0127] Example 12

[0128] In-situ pre-growth of graphene seed crystals was carried out on Inconel 625 alloy using a nanosecond pulsed laser with a maximum power of 30W, and then graphene was grown on this basis using chemical vapor deposition.

[0129] A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes specifically includes the following steps:

[0130] (1) Laser pre-growth of graphene seed crystals on metal substrate surface

[0131] Nano-carbon powder was uniformly dispersed in an ethanol solution and coated onto an Inconel 625 alloy substrate using a spin-coating method to provide the necessary carbon atoms for graphene growth. After drying, the sample was placed in the vacuum chamber of a laser processor to prevent oxidation during the experiment.

[0132] In an argon atmosphere, a nanosecond pulsed laser (maximum power 30W) was used to irradiate the surface of an Inconel 625 alloy substrate. The gas flow rate was 300 g / min, and the irradiation area was 10 mm × 10 mm. The laser process parameters were: spot diameter 43 μm, number of passes 2, laser scanning speed 5 mm / s, laser power 30W, laser frequency 250 kHz, pulse width 350 ns, and width of each scan track 1 mm. This operation achieved the goal of in-situ pre-growth of graphene seed crystals on the substrate surface.

[0133] (2) Graphene growth by chemical vapor deposition

[0134] The product after laser pre-growth of graphene seed crystals was placed in an argon atmosphere for chemical vapor deposition to grow graphene. The holding temperature was 1060℃, the gas ratio was Ar:H2:CH4=30:5:3, the gaseous carbon source was introduced for 15 min, the heating rate was 10℃ / min, and the cooling rate was 5℃ / min. Finally, a graphene / metal wear-resistant material was prepared.

[0135] Figure 1These are optical microscope images and Raman spectroscopy images of the laser-pregrown graphene seed crystals in Example 12. Image (a) shows the typical graphene surface morphology, and image (b) shows the characteristic peaks of the pregrown graphene seed crystals and their relationship to the graphene spectrum. Figure 1 It exhibits the characteristics of multilayered graphene.

[0136] Figure 2 The images shown are optical microscope images and Raman spectroscopy images of the graphene / metal wear-resistant material prepared in Example 12. Figure (a) shows the morphological characteristics of the graphene film grown on the substrate surface, and Figure (b) shows the structural characteristics of the pre-grown graphene seed crystals, which show an increase in the number of graphene seed crystal layers compared to the pre-grown ones.

[0137] Figure 3 The graph shows the friction coefficient of the graphene / metal wear-resistant material prepared in Example 12 as a function of time. As can be seen from the figure, the friction coefficient of the prepared graphene / metal material is reduced compared to the original sample.

[0138] The above 12 embodiments successfully prepared graphene films on the surfaces of different metal materials using different lasers.

[0139] By designing specific graphene growth processes, in-situ growth of graphene films on metal substrates can be achieved, marking a significant step forward in the application of graphene in the field of metal protection. The method of laser alloying to pre-grow graphene seed crystals can improve the bonding strength between the metal substrate and the graphene film. Further graphene growth using chemical vapor deposition ensures high film-substrate bonding strength and yields a large-area, thick, high-quality graphene film, while effectively utilizing graphene's excellent chemical stability and extremely low coefficient of friction. In this invention, a method for preparing graphene / metal wear-resistant materials based on a laser and CVD composite process involves first uniformly pre-coating a solid carbon source on the metal substrate surface, then pre-growing graphene seed crystals using laser irradiation, and finally growing graphene from the laser-pre-grown graphene product using chemical vapor deposition under a protective atmosphere. The resulting graphene film completely covers the metal substrate surface as an independent coating, improving the substrate's friction and wear resistance and chemical stability, while also addressing damage caused by mechanical friction and wear. On the one hand, this method eliminates the need for transfer or spin-coating to bond graphene films to the substrate, significantly enhancing the bonding strength between graphene and the substrate. On the other hand, it allows for the convenient and rapid fabrication of thicker graphene films on metal surfaces over large areas, thereby improving production efficiency and enhancing the friction and wear resistance and chemical stability of the metal substrate. This preparation method enables graphene to serve as an effective barrier, acting as a solid lubricant to reduce friction-induced losses, greatly improving the friction resistance and chemical inertness of the metal substrate, reducing economic losses caused by performance failures, and providing new insights into the application of graphene in metal protection.

[0140] This invention addresses the problem of insufficient friction resistance in existing metallic materials by providing a method for growing graphene on the surface of a metal substrate using a combined laser technology and chemical vapor deposition process. This method solves the problems of insufficient bonding strength between the graphene film on the metal substrate and the substrate, the thinness of the graphene film used as a solid lubricant at the contact surface, the limited amount of graphene, and the inability to maintain good chemical stability and friction resistance. It reduces wear and failure caused by physical friction and temperature changes during service, improves the service life of metals in frictional environments and other related equipment and facilities, and ultimately achieves the goal of reducing losses and improving the service life and safety of metal devices and equipment.

[0141] In summary, the method for preparing graphene / metal wear-resistant materials based on a laser and CVD composite process proposed in this invention has the following advantages: Graphene's inherent chemical stability, extremely low coefficient of friction, and high mechanical strength exhibit excellent properties in the field of metal protection; simultaneously, the prepared graphene film and the metal substrate are metallurgically bonded, resulting in a strong and robust bond; the contact surface is a graphene film with high mechanical strength and a low coefficient of friction, which not only improves the wear resistance of the metal but also enhances its corrosion resistance, mechanical strength, and electrical conductivity; furthermore, chemical vapor deposition can overcome the limitation of laser-based stable large-area growth, enabling large-area controllable in-situ growth of graphene on the metal surface, obtaining high-quality, dense graphene films, and increasing the thickness of the graphene film. This allows the graphene film to act as a solid lubricant on the metal surface, providing a durable guarantee for wear resistance and improved metal mechanical properties, thereby extending the service life of the metal in the field of wear resistance and enhancing safety.

[0142] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing graphene / metal wear-resistant materials based on laser and CVD composite processes, characterized in that, A solid carbon source is pre-placed on the surface of a metal substrate. Under a protective atmosphere, graphene seed crystals are pre-grown on the surface of the metal substrate by laser alloying. Then, graphene is grown by chemical vapor deposition to obtain a graphene / metal wear-resistant material. The solid carbon source includes nano-carbon powder, pencil lead, and solid polystyrene. The particle size of the solid carbon source is 20~100 nm, and the thickness of the pre-layer is 5~100 μm. The parameters of the laser alloying process are: 1~10 processing times, spot diameter 40~100 μm, laser power 10~500 W, laser frequency 30~500 kHz, scanning speed 5~600 mm / s, and pulse width 50~350 ns. The parameters of the chemical vapor deposition method are: holding temperature 1000~1200℃, gas ratio Ar:H2:CH4=30:5:(1~12), gas carbon source introduction time 5~60 min, heating rate 10 ℃ / min, and cooling rate 5℃ / min.

2. The method for preparing graphene / metal wear-resistant material based on laser and CVD composite process according to claim 1, characterized in that, The metal matrix includes nickel-based high-temperature alloys, high-temperature titanium alloys, stainless steel, copper alloys, and aluminum alloys.

3. The method for preparing graphene / metal wear-resistant material based on laser and CVD composite process according to claim 1, characterized in that, The protective atmosphere is argon or nitrogen, with a flow rate of 50~400 g / min.

4. The method for preparing graphene / metal wear-resistant material based on laser and CVD composite process according to claim 1, characterized in that, The laser alloying process uses nanosecond pulsed lasers, fiber lasers, CO2 lasers, or semiconductor lasers, with a maximum power of 10~500 W.

5. A graphene / metal wear-resistant material prepared by any one of the preparation methods of claims 1 to 4.

6. The application of the graphene / metal wear-resistant material according to claim 5 in the field of metal protection.

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