A copper and copper alloy surface build-up coating and applications

Abstract

The application belongs to the field of coating material preparation, and particularly relates to a copper and copper alloy surface surfacing coating and application. The copper and copper alloy surface surfacing coating is that high-entropy alloy powder is surfacing on the surface of a Cu matrix through a plasma surfacing process with appropriate parameters to form a surfacing layer; the high-entropy alloy powder contains copper, and the content of copper is greater than 30 at.%. The interface bonding effect of the coating and the Cu matrix is good, and the coating has a hardness and wear resistance obviously higher than the Cu matrix. The application provides a new idea and method for solving the technical problems that Cu and Cu alloy are easy to oxidize and not resistant to wear in a high-temperature environment, especially, the high-entropy alloy coating-Cu matrix composite metal material prepared by using Cu35Ni25Co25Cr15 high-entropy alloy powder as raw material has good high-temperature wear resistance, and the application range of Cu and Cu alloy in the engineering and mechanical industry is widened.

Description

Technical Field

[0001] The invention belongs to the field of preparation of coating materials, and in particular relates to a copper and copper alloy surface surfacing coating and application thereof. Background Art

[0002] Cu has excellent electrical conductivity, thermal conductivity and corrosion resistance, and has been widely used in industrial fields such as metallurgy, chemical industry, and shipbuilding. However, Cu has poor strength and wear resistance, and a fast high-temperature oxidation rate, which greatly limits its application in the machinery industry. Therefore, in order to expand the application field of Cu, it is particularly important to strengthen Cu. In order to improve the strength and wear resistance of the Cu surface, surface technology is usually used to strengthen Cu, and a layer of alloy coating with higher strength and wear resistance is coated on the surface of the substrate. This not only maintains the excellent performance of the Cu substrate, but also strengthens the strength and wear resistance of the surface, while effectively reducing costs. Among the many surface strengthening technologies, plasma surfacing can be performed directly on the surface of metal parts without complex pretreatment. It is simple and fast to operate, and it is easy to realize mechanization and automation. In addition, the alloy coating of plasma surfacing has a low dilution rate and the weld layer is uniform and beautiful. The coating and the substrate can achieve metallurgical bonding with high bonding strength, which can better play the comprehensive role of the coating and the substrate. Although plasma surfacing technology has achieved certain results and economic benefits in strengthening the surface of steel and Ni-based alloys, the strong thermal conductivity of Cu and Cu alloys causes rapid heat loss in the weld zone during welding, which can easily lead to incomplete fusion and penetration. This can also cause defects such as pores, cracks, and deformation at the surfacing interface, reducing the bonding strength of the coating and thus affecting the mechanical properties. Therefore, there are few reports on coatings with good interface morphology and performance after plasma surfacing on Cu surfaces.

[0003] To achieve a well-bonded and high-performance coating on a Cu substrate, a CuNi alloy was selected as the base material for the coating based on the infinite solid solubility of Cu and Ni. Co and Cr were added to enhance the coating's wear and corrosion resistance, respectively. However, traditional single-element alloys are prone to forming detrimental phases such as intermetallic compounds and brittle phases, making it difficult to maintain microstructure and performance stability. In recent years, high-entropy alloys (HEAs) have garnered increasing attention due to their exceptional mechanical and physicochemical properties. Their high strength and hardness, excellent corrosion and wear resistance, and excellent high-temperature stability have provided valuable insights into the development of high-performance Cu alloys.

[0004] Therefore, how to use plasma surfacing method to prepare a layer of high-entropy alloy coating-Cu matrix composite metal material with stable organizational structure, excellent mechanical properties and wear resistance, especially high-temperature wear resistance, on Cu matrix is ​​a key problem that plagues researchers and companies in the industry. Summary of the Invention

[0005] In order to solve the above technical problems, combined with previous research work, it was found that Cu35Ni25Co25Cr15 high entropy alloy / diamond composite material has good mechanical and wear resistance (patent authorization number: CN114134381B). The present invention selects Cu35Ni25Co25Cr15 high entropy alloy as the research object, and adopts plasma surfacing technology to surfacing Cu35Ni25Co25Cr15 high entropy alloy coating on the surface of Cu substrate. The second purpose of the present invention is to provide a plasma surfacing preparation method of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material. The third purpose of the present invention is to provide an application of the above-mentioned high entropy alloy coating-Cu substrate composite metal material.

[0006] In the present invention, the high-entropy alloy coating is made of Cu35Ni25Co25Cr15 alloy, which has mechanical properties and wear resistance significantly higher than that of the Cu substrate; plasma surfacing technology is selected to prepare the composite metal material, which not only improves the interface bonding strength between the coating and the substrate, but also enhances the mechanical properties such as strength and hardness of the Cu substrate surface, optimizes the wear resistance of the composite metal material, especially the high-temperature wear resistance, and thus broadens the application scope of Cu and Cu alloys in the engineering and machinery industries.

[0007] The present invention is achieved through the following technical solutions:

[0008] The present invention provides a surfacing coating on the surface of copper and copper alloys, wherein high entropy alloy powder is directly surfacing-welded onto the surface of a Cu substrate by a plasma surfacing method to form a surfacing layer, thereby obtaining the surfacing coating on the surface of the copper and copper alloys; the high entropy alloy powder contains copper, and the copper content is greater than 30 at.%. The specific preparation method comprises the following steps:

[0009] (1) Preheating: Dry the high entropy alloy powder at 150-250°C for 2-3 hours and preheat the Cu matrix at 300-400°C for 0.5-1 hour.

[0010] (2) Setting of surfacing parameters. Set the movement path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 10-15 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 8-20 mm. The ion gas used is argon with a gas flow rate of 2-3 L / min. The shielding gas is nitrogen with a gas flow rate of 8-10 L / min. The surfacing current is 110-170 A and the surfacing voltage is 200-230 V.

[0011] (3) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 50-70g / min.

[0012] (4) Overlay welding: The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters to obtain a coating with a set thickness.

[0013] Preferably, the high entropy alloy powder is a Cu35Ni25Co25Cr15 alloy powder with a particle size of 75-150 μm. More preferably, the Cu35Ni25Co25Cr15 high entropy alloy powder is prepared by gas atomization. The gas atomized powder has a fine particle size, is mainly spherical, has good fluidity, and is used for better surfacing effect.

[0014] The ion gas used in the present invention is commercial pure argon, and the protective gas is commercial pure nitrogen.

[0015] Preferably, the Cu substrate is polished with 800-grit sandpaper. More preferably, the surface is sandblasted after polishing.

[0016] Preferably, the distance between the plasma spray gun muzzle and the Cu substrate surface for surfacing welding is 10-18 mm. Further preferably, the distance between the plasma spray gun muzzle and the Cu substrate surface for surfacing welding is 12-15 mm.

[0017] Preferably, the plasma surfacing welding current is 120-160 A. Further preferably, the plasma surfacing welding current is 130-160 A. Even more preferably, the plasma surfacing welding current is 140-160 A. Of course, in specific applications, a plasma surfacing welding current of 145-155 A can also achieve good results.

[0018] Preferably, the surfacing voltage is controlled at 215-225V during surfacing welding. In the present invention, using a voltage of 200V-230V or higher in combination with a high current can further enhance the performance of the coating. In particular, when the voltage is within the range of 220±5V, not only does it not require a special transformer, but it also achieves superior product performance.

[0019] When the high entropy alloy powder is a Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150μm, the performance of the coating can be further improved by using the following process parameters:

[0020] The step rate of the plasma spray gun is set to 12 mm / s, and the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface is 15 mm; the ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min, and the shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min; the surfacing current is 150 A, and the surfacing voltage is 220 V.

[0021] The present invention provides an application of a surfacing coating on the surface of copper and copper alloys; the coating is used in the engineering and / or mechanical industries. Because the Cu35Ni25Co25Cr15 high-entropy alloy coating can improve the high-temperature wear resistance of the Cu substrate, it can be used in high-temperature friction environments, broadening the service range of Cu and Cu alloys in the engineering and mechanical industries.

[0022] The composite metal material designed and prepared by the present invention has a coating dilution rate between 10-40%, a maximum hardness of the coating greater than or equal to 130HV, and an interface bonding strength greater than or equal to 11.5N.

[0023] After optimization, the composite metal material designed and prepared by the present invention has a coating dilution rate between 15-35%, a maximum hardness of the coating greater than or equal to 135HV, an interface bonding strength greater than or equal to 12N, and the composite material is loaded with a load of 30-50N and rubbed at different temperatures for 20 minutes. The wear mass loss after friction at 25°C is no more than 10 mg, the wear mass loss after friction at 300°C is no more than 20 mg, and the wear mass loss after friction at 700°C is no more than 60 mg.

[0024] After further optimization, the composite metal material designed and prepared by the present invention has a coating dilution rate between 20-35%, a maximum hardness of the coating greater than or equal to 140HV, an interface bonding strength greater than or equal to 14N, and the composite material is loaded with a load of 30-50N and rubbed at different temperatures for 20 minutes. The wear mass loss after friction at 25°C is no more than 8 mg, the wear mass loss after friction at 300°C is no more than 15 mg, and the wear mass loss after friction at 700°C is no more than 45 mg.

[0025] After further optimization, the composite metal material designed and prepared by the present invention has a coating dilution rate between 20-30%, a maximum hardness of the coating greater than or equal to 145HV, an interface bonding strength greater than or equal to 15N, and the composite material is loaded with a load of 30-50N and rubbed at different temperatures for 20 minutes. The wear mass loss after friction at 25°C is no more than 6 mg, the wear mass loss after friction at 300°C is no more than 11 mg, and the wear mass loss after friction at 700°C is no more than 37 mg.

[0026] The application adopts the Cu35Ni25Co25Cr15 high-entropy alloy powder after drying as raw material, the substrate is the Cu substrate after polishing by 800 mesh sandpaper, sand blasting treatment and preheating, adopts the plasma surfacing process, sets the step rate of the plasma torch at 10-15 mm / s, the distance between the torch mouth and the Cu substrate surface is 12-15 mm; the commercial pure argon is used as ion gas, the gas flow is 2-3 L / min, the commercial pure nitrogen is used as protective gas, the gas flow is 8-10 L / min; the surfacing voltage is 200-230 V, the surfacing current is 130-160 A; the powder feeding rate is 50-70 g / min. The Cu35Ni25Co25Cr15 high-entropy alloy-Cu substrate composite metal material is prepared. The maximum hardness of the coating is 159.20-190.68 HV, the interface bonding strength is 15.4-78.9 N, the dilution rate is 20.79-29.38%, the wear mass loss after friction at 25 DEG C is 5.1-6.0 mg, the wear mass loss after friction at 300 DEG C is 7.1-10.5 mg, and the wear mass loss after friction at 700 DEG C is 25.9-36.7 mg.

[0027] When the copper and copper alloy adopting the surface surfacing coating designed in the application is used in the service environment of 350 DEG C and below, the following surfacing process can reduce the wear amount of the coating as much as possible; the surfacing process is as follows:

[0028] The movement path of the plasma torch is set to cover the Cu substrate surface, the step rate of the plasma torch is set at 12 mm / s, and the distance between the torch mouth of the plasma torch and the Cu substrate surface is 15 mm; the ion gas used is commercial pure argon, the gas flow is 2.5 L / min, the protective gas is commercial pure nitrogen, and the gas flow is 10 L / min; the surfacing current is 160 A, and the surfacing voltage is 220 V.

[0029] When the copper and copper alloy adopting the surface surfacing coating designed in the application is used in the service environment of 500 DEG C to 750 DEG C, the following surfacing process can reduce the wear amount of the coating as much as possible; the surfacing process is as follows:

[0030] The movement path of the plasma torch is set to cover the Cu substrate surface, the step rate of the plasma torch is set at 12 mm / s, and the distance between the torch mouth of the plasma torch and the Cu substrate surface is 15 mm; the ion gas used is commercial pure argon, the gas flow is 2.5 L / min, the protective gas is commercial pure nitrogen, and the gas flow is 10 L / min; the surfacing current is 150 A, and the surfacing voltage is 220 V.

[0031] Compared with the existing surface strengthening technology, the application has the following beneficial effects:

[0032] (1) The present invention utilizes a plasma surfacing process to prepare a Cu alloy coating on a Cu substrate. This method is simple, quick, and easily mechanized and automated. Currently, there are no particularly successful examples of using plasma surfacing to prepare Cu alloy coatings on Cu or Cu alloy substrates. This invention represents a novel attempt in this research area.

[0033] (2) The present invention uses Cu35Ni25Co25Cr15 high-entropy alloy powder as raw material. This high-entropy alloy has excellent mechanical and wear resistance, especially high-temperature wear resistance. After being surfacing-welded onto a Cu substrate, the mechanical and wear resistance of the Cu substrate surface can be enhanced.

[0034] (3) The Cu35Ni25Co25Cr15 high-entropy alloy selected in the present invention has a dual-phase structure, namely the FCC_A1 phase (Cu-rich phase) and the γˊ phase (NiCoCr-rich phase). After surfacing, the Cu-rich phase is tightly bonded to the Cu substrate, resulting in a good metallurgical bonding effect at the interface, and the interface bonding strength between the coating and the substrate is relatively high.

[0035] (4) The present invention provides a new idea and method for solving the technical problem of Cu being easily oxidized and not wear-resistant in a high-temperature environment. The prepared Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu matrix composite metal material has good high-temperature wear resistance, which broadens the application range of Cu and Cu alloys in the engineering and machinery industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] To more clearly illustrate the embodiments of this application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some of the embodiments described in this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0037] Attachment Figure 1 : Microstructure morphology at the interface between the Cu35Ni25Co25Cr15 high entropy alloy coating and the Cu substrate prepared in Examples 1-4.

[0038] Figure 2 : XRD patterns of the Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal materials prepared in Examples 5-8.

[0039] Figure 3 : Maximum hardness values ​​of the Cu35Ni25Co25Cr15 high entropy alloy coatings prepared in Example 3 and Comparative Examples 1-5.

[0040] Figure 4The wear mass loss of Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu matrix composite metal material prepared in Example 3 and Comparative Examples 1-4 after friction at different temperatures.

[0041] Figure 1 Fig. 1 is a microstructure morphology of the interface between the Cu35Ni25Co25Cr15 high-entropy alloy coating and the Cu matrix prepared in Example 1; Fig. 2 is a microstructure morphology of the interface between the Cu35Ni25Co25Cr15 high-entropy alloy coating and the Cu matrix prepared in Example 2; Fig. 3 is a microstructure morphology of the interface between the Cu35Ni25Co25Cr15 high-entropy alloy coating and the Cu matrix prepared in Example 3; and Fig. 4 is a microstructure morphology of the interface between the Cu35Ni25Co25Cr15 high-entropy alloy coating and the Cu matrix prepared in Example 4. Figure 1 It can be seen that, under the same other surfacing process conditions, the interface bonding between the Cu35Ni25Co25Cr15 high-entropy alloy coating and the Cu matrix is better and better with the increase of the surfacing current. Especially when the surfacing current is increased to 150 A or more and the surfacing voltage is 220 V, the interface between the coating and the matrix appears metallurgical bonding. It can also be seen from the interface morphology that the dilution rate of the coating gradually increases with the increase of the surfacing current, and the high dilution rate can improve the interface bonding strength between the coating and the matrix, which is consistent with the result that the interface bonding force gradually increases.

[0042] It can be seen that, under the same other surfacing process conditions, the interface bonding between the Cu35Ni25Co25Cr15 high-entropy alloy coating and the Cu matrix is better and better with the increase of the surfacing current. Especially when the surfacing current is increased to 150 A or more and the surfacing voltage is 220 V, the interface between the coating and the matrix appears metallurgical bonding. It can also be seen from the interface morphology that the dilution rate of the coating gradually increases with the increase of the surfacing current, and the high dilution rate can improve the interface bonding strength between the coating and the matrix, which is consistent with the result that the interface bonding force gradually increases. Figure 2 It can be seen that the Cu35Ni25Co25Cr15 high-entropy alloy coating has a dual-phase structure, which is FCC_A1 phase (Cu-rich phase) and γ' phase (NiCoCr-rich phase) respectively. By observing the microstructure morphology of the interface, it is found that the Cu-rich phase is closely combined with the Cu matrix, which is conducive to improving the interface bonding force between the coating and the matrix, so that the coating can better play the roles of high strength, high hardness and high wear resistance.

[0043] It can be seen that the Cu35Ni25Co25Cr15 high-entropy alloy coating prepared in Example 3 has the largest hardness value, indicating that the hardness value of the coating is related to the size of the surfacing current and the welding distance. Figure 3 It can be seen that the Cu35Ni25Co25Cr15 high-entropy alloy coating prepared in Example 3 has the largest hardness value, indicating that the hardness value of the coating is related to the size of the surfacing current and the welding distance.

[0044] It can be seen that the Cu35Ni25Co25Cr15 high-entropy alloy coating prepared in Example 3 has the lowest wear mass loss after friction at different temperatures, indicating that the coating has the strongest wear resistance. Combined with the comparison of the hardness, Figure 4 It can be seen that the Cu35Ni25Co25Cr15 high-entropy alloy coating prepared in Example 3 has the largest hardness value, indicating that the hardness value of the coating is related to the size of the surfacing current and the welding distance. Figure 3 It can be seen that the Cu35Ni25Co25Cr15 high-entropy alloy coating prepared in Example 3 has the lowest wear mass loss after friction at different temperatures, indicating that the coating has the strongest wear resistance. Combined with the comparison of the hardness, DETAILED DESCRIPTION

[0045] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0046] Unless otherwise specifically indicated, all the various raw materials, reagents, instruments and equipment and the like used in the present application can be purchased from the market or can be prepared by the existing method.

[0047] The Cu35Ni25Co25Cr15 high-entropy alloy used in the present application includes a high-entropy alloy with Cu content of 34.5-35.5 at.%, Ni content of 24.5-25.5 at.%, Co content of 24.5-25.5 at.%, and Cr content of 14.5-15.5 at.%. In engineering and examples, the Cu35Ni25Co25Cr15 high-entropy alloy used in the present application is a high-entropy alloy with Cu content of 35 at.%, Ni content of 25 at.%, Co content of 25 at.%, and Cr content of 15 at.%.

[0048] Example 1:

[0049] 1. Material preparation:

[0050] (1) Prepare high-entropy alloy powder: select aerosolized Cu35Ni25Co25Cr15 high-entropy alloy powder with particle size of 75-150 μm, and dry the high-entropy alloy powder at 150-250 °C for 2-3 hours.

[0051] (2) Prepare Cu matrix: polish the Cu matrix with 800 mesh sandpaper, then sandblast the surface, and then preheat at 300-400 °C for 0.5-1 hour.

[0052] 2. Preparation of Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu matrix composite metal material:

[0053] (1) Setting of surfacing parameters. Set the movement path of the plasma torch to cover the surface of the Cu matrix, set the step rate of the plasma torch to 12 mm / s, and set the surfacing distance of the plasma torch to the surface of the Cu matrix to 15 mm; the ion gas used is commercial pure argon gas with a gas flow rate of 2.5 L / min, the protective gas is commercial pure nitrogen gas with a gas flow rate of 10 L / min; the surfacing current is 130 A, and the surfacing voltage is 220 V.

[0054] (2) Powder loading. The dried high-entropy alloy powder was loaded into the powder feeder of the plasma surfacing machine, and the powder feeding rate of the powder feeder was set to 60 g / min.

[0055] (3) Surfacing. The plasma torch was used to perform surfacing on the surface of the Cu substrate according to the pre-set motion path and parameters, until a surfacing coating with a thickness of 2 mm was formed on the substrate; a Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material was obtained.

[0056] 3. After polishing the prepared Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material, the microstructure and performance were tested, including the coating dilution rate, the maximum hardness of the coating, the interfacial bonding strength of the coating and the substrate, and the mass loss of the coating after 20 min of grinding against Si3N4 balls at different temperatures (25℃, 300℃ and 700℃). The test results are as follows:

[0057]

[0058] Example 2:

[0059] 1. Material preparation:

[0060] (1) Preparation of high-entropy alloy powder: Select the particle size of 75-150 μm of gas atomized Cu35Ni25Co25Cr15 high-entropy alloy powder, and dry the high-entropy alloy powder at 150-250℃ for 2-3 hours.

[0061] (2) Preparation of Cu substrate: After polishing the Cu substrate with 800 mesh sandpaper, the surface was sandblasted, and then preheated at 300-400℃ for 0.5-1 hour.

[0062] 2. Preparation of Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material:

[0063] (1) Surfacing parameter setting. The motion path of the plasma torch was set to cover the surface of the Cu substrate, the step rate of the plasma torch was set to 12 mm / s, and the surfacing distance between the plasma torch and the surface of the Cu substrate was set to 15 mm; the ion gas used was commercial pure argon gas with a flow rate of 2.5 L / min, the protective gas was commercial pure nitrogen gas with a flow rate of 10 L / min; the surfacing current was 140 A, and the surfacing voltage was 220 V.

[0064] (2) Powder loading. The dried high-entropy alloy powder was loaded into the powder feeder of the plasma surfacing machine, and the powder feeding rate of the powder feeder was set to 60 g / min.

[0065] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0066] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0067]

[0068]

[0069] Example 3:

[0070] 1. Material preparation:

[0071] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0072] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0073] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0074] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 15 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 150 A and the surfacing voltage is 220 V.

[0075] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0076] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0077] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0078]

[0079]

[0080] Example 4:

[0081] 1. Material preparation:

[0082] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0083] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0084] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0085] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 15 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 160 A and the surfacing voltage is 220 V.

[0086] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0087] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0088] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0089]

[0090] Example 5:

[0091] 1. Material preparation:

[0092] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0093] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0094] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0095] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 12 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 130 A and the surfacing voltage is 220 V.

[0096] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0097] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0098] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0099]

[0100] Example 6:

[0101] 1. Material preparation:

[0102] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0103] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0104] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0105] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 12 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 140 A and the surfacing voltage is 220 V.

[0106] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0107] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0108] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0109]

[0110] Example 7:

[0111] 1. Material preparation:

[0112] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0113] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0114] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0115] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 12 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 150 A and the surfacing voltage is 220 V.

[0116] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0117] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0118] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0119]

[0120] Example 8:

[0121] 1. Material preparation:

[0122] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0123] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0124] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0125] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 12 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 160 A and the surfacing voltage is 220 V.

[0126] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0127] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0128] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0129]

[0130] Comparative Example 1:

[0131] 1. Material preparation:

[0132] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0133] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0134] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0135] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 15 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 100 A and the surfacing voltage is 220 V.

[0136] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0137] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0138] 3. After polishing the prepared Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material, test its organization and performance, including coating dilution rate, maximum coating hardness, interface bonding strength between coating and substrate, and mass loss after coating and Si3N4 ball against grinding for 20 min at different temperatures (25℃, 300℃ and 700℃). The test results are as follows:

[0139]

[0140] Comparative Example 2:

[0141] 1. Material preparation:

[0142] (1) Prepare high-entropy alloy powder: select gas atomized Cu35Ni25Co25Cr15 high-entropy alloy powder with a particle size of 75-150μm, and dry the high-entropy alloy powder at 150-250℃ for 2-3 hours.

[0143] (2) Prepare Cu substrate: polish the Cu substrate with 800 mesh sandpaper, then sandblast the surface, and then preheat at 300-400℃ for 0.5-1 hour.

[0144] 2. Preparation of Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material:

[0145] (1) Set the parameters for surfacing. Set the movement path of the plasma torch to cover the surface of the Cu substrate, set the step rate of the plasma torch to 12mm / s, and set the surfacing distance between the plasma torch and the surface of the Cu substrate to 15mm; the ion gas used is commercial pure argon gas with a gas flow rate of 2.5L / min, the protective gas is commercial pure nitrogen gas with a gas flow rate of 10L / min; the surfacing current is 180A and the surfacing voltage is 220V.

[0146] (2) Powder loading. Load the dried high-entropy alloy powder into the powder feeder tank of the plasma surfacing machine, and set the powder feeding rate of the powder feeder tank to 60g / min.

[0147] (3) Surfacing. The plasma torch performs surfacing on the surface of the Cu substrate according to the pre-set movement path and parameters, until a surfacing coating with a thickness of 2mm is formed on the substrate; obtain Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material.

[0148] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0149]

[0150] Comparative Example 3:

[0151] 1. Material preparation:

[0152] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0153] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0154] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0155] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 6 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 150 A and the surfacing voltage is 220 V.

[0156] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0157] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0158] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0159]

[0160] Comparative Example 4:

[0161] 1. Material preparation:

[0162] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0163] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0164] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0165] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 22 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 150 A and the surfacing voltage is 220 V.

[0166] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0167] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0168] 3. After polishing the prepared Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material, test its organization and performance, including coating dilution rate, maximum coating hardness, interface bonding strength between coating and substrate, and mass loss after coating against Si3N4 ball for 20 min at different temperatures (25℃, 300℃ and 700℃). The test results are as follows:

[0169]

[0170]

[0171] Comparative Example 5:

[0172] 1. Material preparation:

[0173] (1) Prepare high-entropy alloy powder: select gas atomized Cu35Ni25Co25Cr15 high-entropy alloy powder with a particle size of 75-150 μm, and dry the high-entropy alloy powder at 150-250℃ for 2-3 hours.

[0174] (2) Prepare Cu substrate: polish the Cu substrate with 800 mesh sandpaper, then sandblast the surface, and then preheat at 300-400℃ for 0.5-1 hour.

[0175] 2. Preparation of Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material:

[0176] (1) Set the parameters for surfacing. Set the movement path of the plasma torch to cover the Cu substrate surface, set the step rate of the plasma torch to 12 mm / s, and set the surfacing distance between the plasma torch and the Cu substrate surface to 22 mm; the ion gas used is commercial pure argon gas with a flow rate of 2.5 L / min, and the protective gas is commercial pure nitrogen gas with a flow rate of 10 L / min; the surfacing current is 100 A, and the surfacing voltage is 220 V.

[0177] (2) Powder loading. Load the dried high-entropy alloy powder into the powder feeder tank of the plasma surfacing machine, and set the powder feeding rate of the powder feeder tank to 60 g / min.

[0178] (3) Surfacing. The plasma torch performs surfacing on the Cu substrate surface according to the pre-set movement path and parameters, until a surfacing coating with a thickness of 2 mm is formed on the substrate; obtain Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material.

[0179] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0180]

[0181]

[0182] Comparative Example 6:

[0183] 1. Material preparation:

[0184] (1) Preparation of high entropy alloy powder: Select atomized Cu35Ni25Co25Cr15 high entropy alloy powder with a particle size of 75-150 μm, and dry the high entropy alloy powder at 150-250°C for 2-3 hours.

[0185] (2) Preparation of Cu substrate: The Cu substrate was polished with 800-grit sandpaper and then sandblasted, and then preheated at 300-400°C for 0.5-1 hour.

[0186] 2. Preparation of Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material:

[0187] (1) Setting of surfacing parameters. Set the motion path of the plasma spray gun to cover the surface of the Cu substrate. Set the step rate of the plasma spray gun to 12 mm / s. Set the surfacing distance between the plasma spray gun muzzle and the Cu substrate surface to 22 mm. The ion gas used is commercial pure argon with a gas flow rate of 2.5 L / min. The shielding gas is commercial pure nitrogen with a gas flow rate of 10 L / min. The surfacing current is 150 A and the surfacing voltage is 90 V.

[0188] (2) Powder loading. Load the dried high entropy alloy powder into the powder feeding tank of the plasma cladding machine and set the powder feeding rate of the powder feeding tank to 60g / min.

[0189] (3) Overlay welding. The plasma spray gun performs overlay welding on the surface of the Cu substrate according to the pre-set motion path and parameters until a 2 mm thick overlay coating is formed on the substrate; thus, a Cu35Ni25Co25Cr15 high entropy alloy coating-Cu substrate composite metal material is obtained.

[0190] 3. The resulting Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite was polished and then subjected to microstructure and performance testing, including coating dilution rate, maximum coating hardness, interfacial bonding strength between the coating and the substrate, and mass loss of the coating after milling with Si3N4 balls for 20 minutes at different temperatures (25°C, 300°C, and 700°C). The test results are as follows:

[0191]

[0192] The present invention utilizes a plasma surfacing method on a Cu substrate to produce a Cu35Ni25Co25Cr15 high-entropy alloy coating with high mechanical properties and wear resistance, particularly high-temperature wear resistance. The coating also exhibits good metallurgical bonding at the interface with the substrate. The Cu35Ni25Co25Cr15 high-entropy alloy-Cu substrate composite metal material prepared by the present invention has a maximum hardness of 159.20-190.68 HV, an interfacial bonding strength of 15.4-78.9 N, and a coating dilution rate of 20.79-29.38%. When the composite material is loaded with a 30 N load and rubbed at different temperatures for 20 minutes, the wear mass loss after friction at 25°C is 5.1-6.0 mg, after friction at 300°C is 7.1-10.5 mg, and after friction at 700°C is 25.9-36.7 mg.

[0193] In summary, the present invention has the following advantages:

[0194] The present invention makes a groundbreaking attempt to improve the surface strength and wear resistance of Cu. First, a plasma surfacing process is used to prepare a Cu35Ni25Co25Cr15 high-entropy alloy coating on a Cu substrate. This method is simple, fast, and easily mechanized and automated. The selected Cu35Ni25Co25Cr15 high-entropy alloy coating has excellent mechanical and wear resistance, especially high-temperature wear resistance. In addition, the Cu35Ni25Co25Cr15 high-entropy alloy has a dual-phase structure, namely a Cu-rich phase and a NiCoCr-rich phase. After surfacing, the Cu-rich phase is tightly bonded to the Cu substrate, forming a good metallurgical bond at the interface. The high interfacial bonding strength is more conducive to the coating's high strength, high hardness, and high wear resistance. Finally, the present invention provides a new idea and method for solving the technical problems of Cu's easy oxidation and poor wear resistance in high-temperature environments. The prepared Cu35Ni25Co25Cr15 high-entropy alloy coating-Cu substrate composite metal material has excellent high-temperature wear resistance, broadening the application range of Cu and Cu alloys in the engineering and machinery industries.

[0195] Finally, it should be noted that the above description of the disclosed embodiments is provided to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A surfacing coating on the surface of copper and copper alloys, characterized by: The high entropy alloy powder is directly surfacing on the surface of the Cu substrate by a plasma surfacing method to form a surfacing layer, thereby obtaining the copper and copper alloy surface surfacing coating; the high entropy alloy powder is a Cu35Ni25Co25Cr15 alloy powder prepared by gas atomization, and the particle size is selected to be 75-150 μm. The preparation method comprises the following steps: (1) Preheating Dry the high entropy alloy powder at 150-250°C for 2-3 hours and preheat the Cu matrix at 300-400°C for 0.5-1 hour; (2) Setting of surfacing parameters The movement path of the plasma spray gun was set to cover the surface of the Cu substrate. The step rate of the plasma spray gun was set to 10-15 mm / s, and the welding distance between the plasma spray gun muzzle and the Cu substrate surface was set to 8-20 mm. The ion gas used was argon with a gas flow rate of 2-3 L / min, and the shielding gas was nitrogen with a gas flow rate of 8-10 L / min. The welding current was 110-170 A, and the welding voltage was 200-230 V. (3) Powder filling The dried high entropy alloy powder is loaded into the powder feeding tank of the plasma cladding machine and the powder feeding rate of the powder feeding tank is set to 50-70 g / min; (4) Surfacing The plasma spray gun performs surfacing welding on the surface of the Cu substrate according to the pre-set motion path and parameters to obtain a coating with a set thickness.

2. The copper and copper alloy surface surfacing coating according to claim 1, characterized in that: In step (2), the distance between the plasma spray gun nozzle and the Cu substrate surface for surfacing welding is 10-18 mm.

3. The copper and copper alloy surface surfacing coating according to claim 2, characterized in that: In the step (2), the distance between the plasma spray gun muzzle and the Cu substrate surface for surfacing is 12-15 mm.

4. The copper and copper alloy surface surfacing coating according to claim 1, characterized in that: The plasma surfacing current in step (2) is 120-160 A.

5. The copper and copper alloy surface surfacing coating according to claim 4, characterized in that: The plasma surfacing current in step (2) is 130-160 A.

6. The copper and copper alloy surface surfacing coating according to claim 5, characterized in that: The plasma surfacing current in step (2) is 145-155 A.

7. The copper and copper alloy surface surfacing coating according to claim 4, characterized in that: In the step (2), the surfacing voltage is 215-225 V.

8. Use of a surfacing coating on the surface of copper and copper alloys according to any one of claims 1 to 7, characterized in that: The coating is used in the engineering and / or mechanical industries.

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