High-hardness wear-resistant composite coating prepared from red light and blue light and preparation method of high-hardness wear-resistant composite coating

Abstract

The invention discloses a high-hardness wear-resistant composite coating prepared by using red and blue light and a preparation method thereof, and the preparation method comprises the following steps: cladding powder A on a copper substrate by using a first beam of blue light in laser cladding to obtain a first intermediate transition layer; cladding the powder B on the first intermediate transition layer by using a second beam of infrared laser in laser cladding, and reacting the powder B on the first intermediate transition layer with nitrogen in the laser cladding process to obtain a second surface functional layer; a third beam of infrared laser in laser cladding is used for irradiating the second surface functional layer, and the high-hardness, high-temperature-resistant and wear-resistant composite coating is prepared. According to the method, efficient regulation and control of the material cladding process are achieved through batch irradiation of the first beam of blue light, the second beam of high-energy infrared laser and the third beam of low-energy infrared laser, and the high-quality coating high in hardness and good in abrasion resistance is prepared through the synergistic effect of the three steps.

Description

Technical Field

[0001] This invention relates to the technical field of coating preparation, specifically to a method for preparing a high-hardness, wear-resistant composite coating using red and blue light, and its application. Background Technology

[0002] Copper alloys are widely used in electronics, electrical engineering, transportation, military and aerospace industries due to their excellent electrical and thermal conductivity and good corrosion resistance. However, the low hardness and poor wear resistance of copper alloys are bottleneck problems that limit their widespread application.

[0003] Wear and other failures in copper alloys during use can cause direct economic losses. For example, replacing a ship's propeller can cost anywhere from tens of thousands to hundreds of thousands of yuan, with even greater losses during downtime. In factories, wear and failure of critical components can result in losses of tens of thousands of yuan per hour due to downtime, and failures in forklift systems or aircraft components can endanger lives.

[0004] Friction in copper alloys occurs only on the surface of the material. Improving the surface wear resistance without significantly altering the basic properties of the copper alloy will be the key to solving surface damage in copper alloy parts.

[0005] Surface coating technology involves forming functional or protective coatings on the surface of a substrate material to improve its wear resistance, corrosion resistance, conductivity, or impart special functions such as antibacterial and decorative effects. Among existing technologies, chemical vapor deposition (CVD) offers strong adhesion and excellent wear and high-temperature resistance, but it requires high-temperature environments and is costly. Physical vapor deposition (PVD) does not require excessively high temperatures, but its adhesion is relatively poor. Electroplating is low-cost and suitable for large-scale production, but uneven coating thickness during processing makes it unsuitable for some precision components. Anodizing generates an oxide layer through electrolysis, offering strong corrosion resistance, but it is only suitable for a limited number of metals. Laser cladding is a surface modification technology that uses a high-energy laser beam to melt metal powder or wire and metallurgically bond it to the substrate. This bonding method results in extremely strong adhesion between the coating and the substrate, making it difficult to peel off, and it also offers high processing precision and uniform thickness, making it widely used in mechanical parts repair and marine equipment corrosion protection.

[0006] Laser cladding uses a high-energy laser beam to metallurgically bond wear-resistant materials to a copper substrate. While retaining the core properties of the copper alloy substrate, it can significantly improve surface hardness (up to 2 to 3 times that of the substrate) and wear resistance, thereby effectively extending the service life of key components and reducing downtime, maintenance, and replacement costs caused by wear.

[0007] Copper, as a typical highly reflective metal, exhibits a reflectivity of over 95% for infrared lasers. At low laser energies, it cannot melt the coating and substrate materials, while excessively high energies cause severe fluctuations in the molten pool, leading to coating defects. This directly results in the difficulty of forming a stable molten pool on copper alloy surfaces using traditional infrared lasers. Although the absorption rate of blue light (450nm band) on copper surfaces can reach over 65%, the output power density of existing blue lasers is generally insufficient (typically <5000W), failing to meet the energy density requirements for cladding high-melting-point materials. Currently, domestic and international researchers are conducting laser cladding experiments by superimposing red and blue lasers. However, even after superimposing red and blue lasers, the high reflectivity of copper alloys to high-energy infrared lasers persists. Severe fluctuations and severe spatter cause molten pool instability, and energy loss prevents the melting of high-melting-point powders, resulting in poor forming quality. Therefore, while simply superimposing red and blue light power can suppress molten pool fluctuations, it cannot completely eliminate core problems such as spatter and absorptivity oscillations. The problems of spatter and fluctuations caused by the high reflectivity of copper alloys to infrared lasers remain fundamentally unresolved. Summary of the Invention

[0008] The purpose of this invention is to provide a method for preparing high-hardness, wear-resistant composite coatings using red and blue light, and its application. This process proposes a method for additive manufacturing of copper alloy surfaces by simultaneously cladding with three laser beams at different times and positions. The cladding process is efficiently controlled by irradiating the material in batches with a first blue laser, a second high-energy infrared laser, and a third low-energy infrared laser. First, a thin nickel coating is clad onto the copper alloy surface using blue light to mitigate the thermal property differences between copper and high-melting-point metals and to address the issue of copper directly reflecting the second infrared laser beam. The second high-energy infrared laser is then used to clad high-melting-point powder materials. The introduction of the third low-energy infrared laser avoids excessive temperature differences before and after cladding, which could lead to cracking (due to the large temperature difference between the rapid heating and cooling of the molten pool after infrared laser scanning). Through the synergistic effect of these three steps, a high-hardness, wear-resistant, high-quality coating is prepared.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] The first aspect of this invention is to provide a method for preparing a high-hardness, wear-resistant composite coating using red and blue light, comprising the following steps:

[0011] (1) Powder A is clad onto the copper substrate using the first blue light in laser cladding to obtain the first intermediate transition layer;

[0012] (2) Powder B is clad onto the first intermediate transition layer using the second infrared laser (high-energy infrared laser) in laser cladding. At the same time, during the laser cladding process, powder B on the first intermediate transition layer reacts with nitrogen to obtain the second surface functional layer.

[0013] (3) A high-hardness, high-temperature resistant and wear-resistant composite coating is obtained by irradiating the second surface functional layer with the third infrared laser (low-energy infrared laser) in laser cladding.

[0014] Among them, the first blue light beam, the second infrared laser beam, and the third infrared laser beam are kept on the same line and parallel in their direction of travel (that is, the first blue light beam, the second infrared laser beam, and the third infrared laser beam all propagate along the same straight path and are parallel to each other).

[0015] The melting point of powder A is lower than that of powder B.

[0016] As a preferred implementation method,

[0017] Step (1),

[0018] The powder A is selected from at least one of nickel powder (Ni), NiCu, or NiCr powder; and / or

[0019] The particle size of powder A is 10-35 μm; and / or,

[0020] The wavelength of the first blue light beam is 400nm-550nm; and / or,

[0021] The power of the first blue light beam is 1500-3000W; and / or,

[0022] The diameter of the first blue light spot is 1 mm-4 mm; and / or,

[0023] The powder feeding rate for laser cladding using the first blue light beam is 1 g / min - 10 g / min; and / or,

[0024] The laser scanning speed for laser cladding using the first blue light beam is 10 mm / s-50 mm / s; and / or,

[0025] The protective gas used for laser cladding using the first blue light beam is argon; and / or,

[0026] The thickness of the first intermediate transition layer is 100μm-200μm; and / or,

[0027] The copper matrix is ​​pure copper, chromium zirconium copper, or aluminum oxide dispersed copper oxide.

[0028] As a preferred implementation method,

[0029] Step (2),

[0030] The powder B is selected from at least one of W, Re, Ta, Mo, and Nb; and / or,

[0031] The particle size of powder B is 15-53 μm; preferably, the particle size of powder A is smaller than that of powder B; and / or,

[0032] The first blue laser beam emerges 0.5-0.6 seconds earlier than the second infrared laser beam; and / or,

[0033] The second infrared laser beam is located directly behind the first blue laser beam, and the distance between the first blue laser beam and the second infrared laser beam is 5mm-30mm.

[0034] As a preferred implementation method,

[0035] Step (2),

[0036] The wavelength of the second infrared laser beam is 1000nm-1200nm; and / or,

[0037] The power of the second infrared laser beam is 2000W-4000W; and / or,

[0038] The spot diameter of the second infrared laser beam is 1mm-4mm; and / or,

[0039] The powder feeding rate for laser cladding using the second infrared laser beam is 8-20 g / min; and / or,

[0040] The laser scanning speed for laser cladding using the second infrared laser beam is 10 mm / s-50 mm / s.

[0041] As a preferred implementation method,

[0042] Step (2),

[0043] The protective gas for laser cladding using the second infrared laser beam is nitrogen; simultaneously with the emission of the second infrared laser beam, the nitrogen gas is ejected, causing the powder B on the first intermediate transition layer to react with the nitrogen gas; and / or,

[0044] The nitrogen gas injection rate is 8-20 g / min; and / or,

[0045] The thickness of the second surface functional layer is 0.4mm-1mm.

[0046] As a preferred implementation method,

[0047] Step (3),

[0048] The second infrared laser beam emerges 0.5-0.6 seconds earlier than the third infrared laser beam; and / or,

[0049] The third infrared laser beam is located directly behind the second infrared laser beam, and the distance between the third infrared laser beam and the second infrared laser beam is 5mm-30mm.

[0050] As a preferred implementation method,

[0051] Step (3),

[0052] The wavelength of the third infrared laser beam is 1000nm-1200nm; and / or,

[0053] The power of the third infrared laser beam is 500W-1000W; and / or,

[0054] The diameter of the spot of the third infrared laser beam is 1mm-4mm; and / or,

[0055] The laser scanning speed for laser cladding using the third infrared laser beam is 10 mm / s-50 mm / s; and / or,

[0056] The protective gas for laser cladding using the third infrared laser beam is argon.

[0057] A second aspect of the present invention is to provide a high-hardness, wear-resistant composite coating prepared by the method according to the first aspect of the present invention.

[0058] As a preferred implementation method,

[0059] The hardness of the high-hardness wear-resistant composite coating is 500-600 HV; and / or,

[0060] The wear rate of the high-hardness wear-resistant composite coating is 5×10⁻⁶. -7 mm³ / N·m ~6.5×10 -7 mm³ / N·m.

[0061] The third aspect of the present invention is to provide the application of the high-hardness wear-resistant composite coating prepared by the method of the first aspect of the present invention using red and blue light in wear-resistant equipment.

[0062] Infrared laser cladding technology faces technical bottlenecks in the surface processing of copper alloy substrates. Copper metal has a reflectivity of over 95% for near-infrared laser light (1064nm wavelength, infrared laser band). This inherent optical characteristic directly results in extremely low energy absorption efficiency of the copper surface under infrared laser irradiation; at conventional power densities, less than 5% of the light energy is converted into effective heat energy. Secondly, copper's exceptional thermal conductivity of 397 W / m·K further exacerbates energy dissipation. Applying laser cladding coatings to copper alloy surfaces requires higher power, but excessively high power can lead to dynamic instability of the molten pool, causing severe problems such as melt spatter, porosity defects, and element loss. More importantly, even if a molten pool is formed, an excessively rapid cooling rate makes it difficult to achieve an effective metallurgical bond between the cladding layer and the substrate.

[0063] Although blue light reduces the reflectivity of copper surfaces, its energy is low. When faced with the cladding requirements for preparing high-melting-point coatings (such as W, Re, Ta, Mo, Nb, etc.) on copper alloy substrates, it simply cannot provide enough energy to completely melt the powder particles.

[0064] Currently, scholars at home and abroad are conducting laser cladding experiments by superimposing red and blue lasers. However, even after superimposing red and blue lasers, the copper alloy still has the problem of high reflection of high-energy infrared lasers. Violent fluctuations and severe spatter cause instability of the molten pool. At the same time, energy loss makes it impossible to melt high-cladding powders (such as W, Re, Ta, Mo, Nb, etc.), resulting in poor forming quality.

[0065] The high reflectivity of solid copper alloys to infrared lasers causes severe fluctuations in the molten pool, a problem that exists regardless of whether infrared lasers are used alone or in combination with infrared lasers. The purpose of this invention is to solve this problem, and the solution is as follows:

[0066] 1) First, a first beam of blue light is emitted to melt the copper alloy substrate and simultaneously clad the intermediate nickel-based transition layer. Then, a second high-energy infrared laser is emitted, simultaneously delivering refractory high-melting-point alloy powder. Finally, a third low-energy infrared laser is emitted for the slow cooling of the coating. In the second step, the high-energy infrared laser acts directly on the first intermediate transition layer, such as the nickel layer. This solves the problem of high reflectivity of solid copper to infrared lasers, thus conserving sufficient energy to fully melt the material and maintain a stable molten pool. In the forward direction, the blue light is always ahead of the high-energy infrared laser, and the high-energy infrared laser is always ahead of the low-energy infrared laser. The first beam of blue light is mainly used to prepare a nickel transition layer on the copper alloy surface, mitigating the thermal property differences between copper and the high-melting-point coating, and preventing the second high-energy infrared laser beam from being reflected by the copper alloy. The second infrared laser beam acts directly on the nickel surface, preserving most of its energy and thus leveraging the high-energy characteristics of the infrared laser to achieve efficient melting of the powder. Simultaneously, nitrogen gas is ejected. High-melting-point refractory alloys can react with nitrogen gas at high temperatures (>1000°C) to form stable nitrides (such as TaN and NbN). These compounds have high hardness, high melting point, and good electrical conductivity. The nitrided coating has high overall hardness, high melting point, and good electrical conductivity.

[0067] 2) High-melting-point refractory powders are relatively hard and brittle, and prone to cracking under rapid laser heating and cooling. To address this issue, a third low-energy infrared laser is introduced as an auxiliary heat source. This third-beam modulation technology, through post-laser heating, significantly reduces the temperature gradient and slows the cooling rate during the second infrared laser cladding process. This reduces residual stress and suppresses porosity and crack defects, thereby improving coating density and bonding strength. The optimized cladding layer retains ultra-high hardness, conductivity, and wear resistance while also possessing high bonding strength and low porosity, resulting in corrosion resistance and fatigue resistance, effectively avoiding delamination and cracking risks. This technological breakthrough further expands the application potential of high-melting-point powders in high-temperature protective coatings and heavy-duty wear-resistant components, achieving a synergistic improvement in performance advantages and molding quality.

[0068] In summary, this process proposes a method for additive manufacturing of copper alloy surface cladding using three laser beams with different emission times and positions. The cladding process is efficiently controlled by irradiating the copper alloy surface in batches with a first blue laser, a second high-energy infrared laser, and a third low-energy infrared laser. First, a thin nickel coating is clad onto the copper alloy surface using blue laser to mitigate the thermal property differences between copper and high-melting-point metals and to address the issue of copper directly reflecting the second infrared laser beam. The second high-energy infrared laser is then used to clad the high-melting-point powder material. The introduction of the third low-energy infrared laser prevents excessive temperature differences before and after cladding, which could lead to cracking (due to the large temperature difference between the rapid heating and cooling of the molten pool after infrared laser scanning). Through the synergistic effect of these three steps, a high-quality coating with high hardness and good wear resistance is prepared. Attached Figure Description

[0069] Figure 1 A schematic diagram of the laser cladding process provided for the implementation of this invention.

[0070] Explanation of reference numerals in the attached figures:

[0071] 1-First blue light; 2-Second infrared laser; 3-Third infrared laser; 4-Powder A; 5-Copper substrate; 6-First intermediate transition layer; 7-Powder B; 8-Molten pool of powder B; 9-High-hardness, high-temperature resistant, and wear-resistant composite coating. Detailed Implementation

[0072] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0073] like Figure 1 As shown, this invention provides a method for preparing a high-hardness, wear-resistant composite coating using red and blue light, comprising the following steps:

[0074] (1) Powder A4 is clad onto copper substrate 5 using the first blue light 1 in laser cladding to obtain the first intermediate transition layer 6;

[0075] (2) The second infrared laser 2 in the laser cladding process is used to clad powder B 7 on the first intermediate transition layer. At the same time, during the laser cladding process, a molten pool 8 of powder B is formed, and the powder B on the first intermediate transition layer reacts with nitrogen to obtain the second surface functional layer.

[0076] (3) The high-hardness, high-temperature resistant and wear-resistant composite coating 9 is obtained by irradiating the second surface functional layer with the third infrared laser 3 in laser cladding.

[0077] Before processing, the surface of the copper alloy (e.g., chromium zirconium copper, dispersed copper, pure copper) substrate is ground with a grinding machine and then cleaned and dried with alcohol. High-melting-point metal powder Ta (or W, Re, Mo, Nb, etc.) and intermediate transition layer powders such as nickel powder (Ni), NiCu, or NiCr) are placed in a drying oven, and the temperature is adjusted to 120℃. After drying for 60 minutes, high-melting-point metal powder molybdenum powder is placed in powder feeder B, and intermediate transition layer nickel powder is placed in powder feeder A. At this time, the height of the laser nozzle from the copper alloy substrate is adjusted to between 15-30 mm, and the angle with the horizontal plane is between 70-85 degrees. The protective gas is argon or nitrogen. After the machine position is adjusted, the machine begins to clad the copper alloy surface.

[0078] The process begins with the first blue laser beam being emitted and powder feeder A starting simultaneously. The blue laser power is 1500-2000W, the spot diameter is 2mm, the cladding overlap rate is selected as 50%-70%, the powder feeding rate is 1-10g / min, and the laser scanning speed is set to 10mm / s-50mm / s. At this point, the blue laser can effectively melt the low-melting-point copper alloy first, while simultaneously cladding a nickel coating on the substrate surface. The nickel coating thickness is approximately 100μm-150μm. 0.5-0.6 seconds after the first blue laser beam is emitted / advanced, a second high-power infrared laser beam is emitted, and powder feeder B is activated to emit powder while simultaneously spraying nitrogen gas. The coaxial powder feeding system B delivers high-melting-point molybdenum powder with a particle size of 15-45μm. The second high-power infrared laser beam is positioned 5-30mm directly behind the first blue laser beam. After the blue light irradiation lasts for 0.5-0.6 seconds, a thin nickel coating has been formed. At this time, the second infrared laser beam acts directly on the nickel layer, and most of the energy is saved for melting the high-melting-point powder. The infrared laser power is 2000W-4000W, the spot diameter is 2 mm, the cladding overlap rate is 50%-70%, and the laser scanning speed is set to 10mm / s-50mm / s (consistent with the first beam). The gas flow rate is 2-10L / min to further melt the high-melting-point alloy molybdenum powder (or W, Re, Ta, Mo, Nb, etc.). In addition to avoiding the reflection of the infrared laser by copper, the nickel intermediate layer can also serve as a transition layer to reduce the large difference in thermal properties between the copper substrate and the high-melting-point alloy, thus preventing cracking during preparation or use. Simultaneously, nitrogen gas is ejected, causing the entire coating to undergo a nitriding reaction. A third low-energy infrared laser is positioned directly behind the high-energy infrared laser. This laser beam has an energy of 100W-800W and a scanning speed of 10mm / s-50mm / s (consistent with the first and second beams). The three beams remain parallel and aligned in their forward direction. The third low-power infrared laser is emitted 0.5-0.6 seconds after the second high-energy infrared laser. This third low-power infrared laser is positioned 5-30mm directly behind the second high-power infrared laser. This third low-energy infrared laser provides lower heat input, preventing excessively rapid cooling and allowing for slow cooling without affecting the coating's existing properties, thus avoiding cracking.

[0079] After the blue light liquefies the solid copper and coats it with an intermediate nickel transition layer, completing the formation of the molten pool at the current point, it moves forward. The first infrared laser beam is emitted at the lag distance L (5-30mm apart), while high-melting-point alloy powder (such as W, Re, Ta, Mo, Nb, etc.) and nitrogen gas are sprayed into the molten pool. During its solidification stage, the third low-energy infrared laser beam reduces the cooling rate to avoid excessive stress and brittleness that could lead to cracking, resulting in a uniform structure and stable performance, ultimately obtaining a high-performance, high-quality coating.

[0080] Specific implementation plan:

[0081] Before processing, the surface of the copper alloy (e.g., chromium zirconium copper, dispersed copper, pure copper) substrate is ground with a grinding machine and cleaned and dried with alcohol. High-melting-point metal powder B (or W, Re, Ta, Mo, Nb, etc.) and intermediate transition layer powder A (e.g., nickel powder, NiCu, or NiCr) are placed in a drying oven, and the temperature is adjusted to 120℃ for 60 minutes. Powder B is then placed in powder feeder B, and powder A is placed in powder feeder A. At this point, the height of the laser nozzle from the copper alloy substrate is adjusted to between 15-30 mm, and the angle between the laser nozzle and the horizontal plane of the copper alloy substrate is between 70-85 degrees. The protective gas is argon or nitrogen. After the machine position is adjusted, the machine begins to clad the copper alloy surface.

[0082] The process begins with the first blue laser beam being emitted and powder feeder A starting simultaneously for laser cladding. The cladding overlap rate is selected to be 50%-70%. At this stage, the blue laser effectively melts the low-melting-point copper alloy while simultaneously cladding a nickel coating onto the substrate surface. The nickel coating thickness is approximately 100μm-150μm. 0.5-0.6 seconds after the first blue laser beam is emitted / advanced, a second high-power infrared laser beam is emitted, and powder feeder B is activated to dispense powder while simultaneously spraying nitrogen gas. The coaxial powder feeding system B delivers the powder. The second high-power infrared laser beam is positioned 5-30mm directly behind the first blue laser beam. When the blue laser irradiation duration is reached, a relatively thin nickel coating has formed. The second infrared laser beam then acts directly on the nickel layer, conserving most of its energy to melt the high-melting-point powder, forming the second surface functional layer. Furthermore, the nickel interlayer not only prevents copper from reflecting the infrared laser but also serves as a transition layer, reducing the significant thermophysical differences between the copper substrate and the high-melting-point alloy, thus preventing cracking during preparation or use. A third low-energy infrared laser is positioned directly behind the second high-energy infrared laser beam. This third infrared laser beam has a lower energy than the second one. The three beams are aligned and parallel in their forward direction. The third low-energy infrared laser beam is emitted 0.5-0.6 seconds after the second high-energy infrared laser beam. The third low-energy infrared laser beam is positioned 5-30 mm behind the second high-energy infrared laser beam. This third low-energy infrared laser beam provides lower heat input, preventing excessive cooling and allowing the coating to cool slowly without affecting its existing properties, thus avoiding cracking. At the same time, nitrogen gas is emitted, causing a nitriding reaction to occur on the surface of the coating.

[0083] After the first blue light liquefies the solid copper and melts the intermediate nickel transition layer, completing the formation of the molten pool at the current point, it moves forward. The second infrared laser is emitted at the lag distance L (5-30mm apart) and simultaneously sprays powder B into the molten pool. During its solidification stage, the third low-energy infrared laser reduces the cooling rate to avoid excessive stress and brittleness that could lead to cracking, resulting in a uniform structure and ultimately obtaining a high-performance, high-quality coating.

[0084] Example 1

[0085] (1) Before processing, the surface of the pure copper substrate is polished with a grinding machine and cleaned and dried with alcohol. Adjust the height of the laser nozzle and the pure copper substrate to 18 mm and the angle between the laser nozzle and the horizontal plane of the pure copper substrate to 80 degrees. After adjusting the machine position, the machine starts to prepare the first intermediate transition layer by laser cladding on the pure copper substrate. Place the nickel powder (particle size of 10-35 μm) into the powder feeder A, start the first beam of blue light for laser cladding and start the powder feeder A at the same time. During laser cladding, the protective gas is argon, the laser power of the blue light is 1800W, the wavelength is 450nm, the spot diameter is 2 mm, the cladding overlap rate is selected as 60%, the powder feeding rate is 5g / min, and the laser scanning speed is set to 25mm / s. At this time, the blue light can be effectively used to melt the low melting point copper alloy first, and at the same time, a nickel coating is clad on the substrate surface. The thickness of the nickel coating is about 100μm.

[0086] (2) After the first blue light beam exits / advances for 0.5 seconds, a second high-power infrared laser beam is emitted, and powder feeder B is opened to discharge powder while simultaneously spraying nitrogen gas. The coaxial powder feeding system delivers tantalum powder, a high-melting-point metal powder with a particle size of 15-53 μm, from powder feeder B. The second high-power infrared laser beam is 12.5 mm behind the first blue light beam. When the blue light irradiation duration reaches its limit, a thin nickel coating has been formed. At this time, the second infrared laser beam directly acts on the nickel layer, and most of its energy is preserved for melting the high-melting-point powder. The infrared laser has a power of 3000 W and a wavelength of 1150 nm. The spot diameter is 2 mm, the cladding overlap rate is selected as 60%, the laser scanning speed is set to 25 mm / s (consistent with the first beam), and the powder feeding rate is 10 g / min to further melt the high melting point alloy tantalum powder (the nickel intermediate layer can not only avoid the reflection of the infrared laser by copper, but also serve as a transition layer to reduce the large difference in thermal properties between the copper substrate and the high melting point alloy, thus avoiding cracking during preparation or use). At the same time, nitrogen gas is sprayed at a spray rate of 10 g / min (i.e., the protective gas for laser cladding is nitrogen gas). At this time, the entire coating undergoes a nitriding reaction to obtain the second surface functional layer; the thickness of the second surface functional layer is 0.6 mm.

[0087] (3) Then, a third low-energy infrared laser is set directly behind the second high-power infrared laser. The energy of this infrared laser is 700W, the wavelength is 1150nm, the spot diameter is 2mm, and the laser scanning speed is set to 25mm / s (consistent with the direction of the first and second lasers). The protective gas is argon. The three lasers are kept on the same line and parallel in the forward direction. The third low-power infrared laser is emitted 1 (0.5s) after the second high-power infrared laser emits light / advances. The third low-power infrared laser is 12.5mm away from the second high-power infrared laser. The third low-power infrared laser can provide lower heat input, and prevents the coating from cooling down too quickly without affecting the existing performance of the coating, so as to avoid cracking.

[0088] Example 2

[0089] (1) Before processing, the surface of the pure copper substrate is polished with a grinding machine and cleaned and dried with alcohol. Adjust the height of the laser nozzle and the pure copper substrate to 18 mm and the angle between the laser nozzle and the horizontal plane of the pure copper substrate to 70 degrees. After adjusting the machine position, the machine starts to prepare the first intermediate transition layer by laser cladding on the pure copper substrate. Place the nickel powder (particle size of 10-35 μm) into the powder feeder A, start the first beam of blue light for laser cladding and start the powder feeder A at the same time. During laser cladding, the protective gas is argon, the laser power of the blue light is 1800W, the wavelength is 450nm, the spot diameter is 2 mm, the cladding overlap rate is selected as 60%, the powder feeding rate is 5g / min, and the laser scanning speed is set to 25mm / s. At this time, the blue light can be effectively used to melt the low melting point copper alloy first, and at the same time, a nickel coating is clad on the substrate surface. The thickness of the nickel coating is about 100μm.

[0090] (2) After the first blue light beam is emitted / advanced for 0.6 seconds, a second high-power infrared laser beam is emitted and the powder feeder B is turned on to emit powder and simultaneously spray nitrogen gas. The coaxial powder feeding system B delivers high-melting-point metal powder (Nb powder) with a particle size of (15-45μm). The second high-power infrared laser beam is 15mm behind the first blue light beam. When the blue light irradiation duration reaches the specified time, a thin nickel coating has been formed. At this time, the second infrared laser beam directly acts on the nickel layer, and most of the energy is preserved for melting the high-melting-point powder. The infrared laser has a power of 2500W and a wavelength of 1150 nm. nm, spot diameter 2 mm, cladding overlap rate selected 60%, laser scanning speed set to 25 mm / s, powder feeding rate 12 g / min to further melt high melting point Nb powder. In addition to avoiding the reflection of infrared laser by copper, the nickel intermediate layer can also serve as a transition layer to reduce the large difference in thermal properties between copper substrate and high melting point alloy, avoiding cracking during preparation or use. At the same time, nitrogen gas is sprayed at a spray rate of 9 g / min (i.e., the protective gas for laser cladding is nitrogen gas). At this time, the entire coating undergoes a nitriding reaction to obtain the second surface functional layer; the thickness of the second surface functional layer is 0.8 mm.

[0091] (3) Then, behind the second high-power infrared laser, and behind the high-energy infrared laser, a third low-energy infrared laser is set. The energy of this infrared light is 700W, the wavelength is 1150nm, the spot diameter is 2mm, and the laser scanning speed is set to 25mm / s (consistent with the first and second lasers). The protective gas is argon. The three lasers are kept on the same line and parallel in the forward direction. The third low-power infrared laser is emitted 0.6s after the second high-energy infrared laser is emitted / advanced. The third low-power infrared laser is 15mm behind the second high-power infrared laser. The third low-energy infrared laser can provide lower heat input. Without affecting the existing performance of the coating, it prevents the temperature from dropping too quickly and allows it to cool slowly to avoid cracking. At the same time, nitrogen gas is sprayed out. At this time, the coating surface undergoes a nitriding reaction.

[0092] Comparative Example 1

[0093] It adopts the same technical solution as Example 1, except that the operation of using the third infrared laser in laser cladding to irradiate the second surface functional layer is not performed. That is, only laser cladding using the first blue light and laser cladding using the second infrared laser are performed.

[0094] Comparative Example 2

[0095] It adopts the same technical solution as Example 1, except that the protective gas for laser cladding with the second infrared laser is argon.

[0096] Comparative Example 3

[0097] It adopts the same technical solution as Example 1, except that the preparation of nickel coating in step (1) is not carried out, and only the first blue light in step (1) is used for blue light irradiation, but powder A is not added.

[0098] The properties of the composite coating prepared by the above method are shown in Table 1.

[0099] Table 1

[0100] Example hardness Wear rate (mm³ / N·m) Example 1 550HV <![CDATA[5.2×10 -7 ]]> Example 2 600HV <![CDATA[6.3×10 -7 ]]> Comparative Example 1 300HV <![CDATA[6.9×10 -7 ]]> Comparative Example 2 380HV <![CDATA[7.6×10 -7 ]]> Comparative Example 3 280HV <![CDATA[7.8×10 -7 ]]>

[0101] The results in Table 1 show that in Comparative Example 1, where the third infrared laser beam used in laser cladding is not applied to the second functional surface layer (i.e., only the first blue laser beam and the second infrared laser beam are used for laser cladding), the refractory powder will crack due to rapid cooling, disrupting the coating's continuity. Local areas will lose their load-bearing capacity due to stress concentration, macroscopically manifesting as reduced hardness. During the friction and wear test, the crack edges expand due to cyclic stress, ultimately leading to coating peeling (abrasive wear) and significantly increasing the wear volume. It also causes lubrication failure; while an intact TaN coating can reduce adhesive wear due to its high hardness, cracked abrasive debris (such as Ta2O5 particles) may act as a third abrasive, exacerbating wear. Therefore, not using the third beam results in poor surface quality during coating preparation, leading to cracking and severe wear.

[0102] As can be seen from the results in Table 1, when the protective gas for laser cladding using the second infrared laser in Comparative Example 2 is argon, the absence of nitrogen to produce a nitriding reaction will result in low coating hardness and increased coating wear.

[0103] As can be seen from the results in Table 1, in Comparative Example 3, failing to first emit blue light to melt the copper alloy substrate and simultaneously clad the intermediate nickel-based transition layer will cause the copper substrate to have high reflectivity to high-energy infrared lasers. The violent fluctuations and severe spatter will cause the molten pool to be unstable, resulting in poor forming quality.

[0104] In summary, this invention achieves efficient control of the material cladding process by irradiating the material in batches with a first blue light beam, a second high-energy infrared laser beam, and a third low-energy infrared laser beam. Through the synergistic effect of these three steps, a high-quality coating with high hardness and good wear resistance is prepared.

[0105] The above embodiments are merely illustrative examples and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing high hardness wear resistant composite coating using red and blue light, characterized in that, The method comprises the following steps: (1) using a first blue light in laser cladding to clad powder A on a copper substrate to obtain a first layer of intermediate transition layer; (2) using a second infrared laser in laser cladding to clad powder B on the first intermediate transition layer, and at the same time, in the process of laser cladding, making the powder B on the first layer of intermediate transition layer react with nitrogen to obtain a second layer of surface functional layer; (3) using a third infrared laser in laser cladding to irradiate on the second layer of surface functional layer to prepare a high-hardness high-temperature-resistant wear-resistant composite coating; wherein the first blue light, the second infrared laser and the third infrared laser are kept in the same line and parallel in the forward direction; The melting point of the powder A is lower than that of the powder B.

2. The method for preparing a high-hardness wear-resistant composite coating by using red and blue light according to claim 1, characterized in that: step (1), the powder A is selected from at least one of nickel powder, NiCu or NiCr powder; and / or, the particle size of the powder A is 10-35 μm; and / or, the wavelength of the first blue light is 400 nm-550 nm; and / or, the power of the first blue light is 1500-3000 W; and / or, the spot diameter of the first blue light is 1 mm-4 mm; and / or, the powder feeding rate of laser cladding using the first blue light is 1 g / min-10 g / min; and / or, the laser scanning speed of laser cladding using the first blue light is 10 mm / s-50 mm / s; and / or, the protective gas of laser cladding using the first blue light is argon; and / or, the thickness of the first layer of intermediate transition layer is 100 μm-200 μm; and / or, the copper substrate is pure copper, chromium-zirconium copper or aluminum oxide dispersed copper.

3. The method for preparing a high-hardness wear-resistant composite coating by using red and blue light according to claim 1, characterized in that: step (2), the powder B is selected from at least one of W, Re, Ta, Mo and Nb; and / or, the particle size of the powder B is 15-53 μm; and / or, the light emission time of the first blue light laser is 0.5-0.6 s earlier than that of the second infrared laser; and / or, the second infrared laser is located directly behind the first blue light, and the distance between the first blue light and the second infrared laser is 5 mm-30 mm.

4. The method for preparing a high-hardness wear-resistant composite coating by using red and blue light according to claim 1, characterized in that: step (2), the wavelength of the second infrared laser is 1000 nm-1200 nm; and / or, the power of the second infrared laser is 2000 W-4000 W; and / or, the spot diameter of the second infrared laser is 1 mm-4 mm; and / or, the powder feeding rate of laser cladding using the second infrared laser is 8-20 g / min; and / or, the laser scanning speed of laser cladding using the second infrared laser is 10 mm / s-50 mm / s. 5.The method of claim 1, wherein: the step (2) is performed by using the second infrared laser beam to perform laser cladding on the first layer of the intermediate transition layer; the nitrogen gas is sprayed out at the same time when the second infrared laser beam emits light, so that the powder B on the first layer of the intermediate transition layer reacts with the nitrogen gas; and / or the spraying rate of the nitrogen gas is 8-20 g / min; and / or the thickness of the second layer of the surface functional layer is 0.5-1 mm. 6.The method of claim 1, wherein: the step (3) is performed by using the third infrared laser beam to perform laser cladding on the second layer of the intermediate transition layer; the second infrared laser beam emits light 0.5-0.6 s earlier than the third infrared laser beam; and / or the third infrared laser beam is located directly behind the second infrared laser beam, and the distance between the third infrared laser beam and the second infrared laser beam is 5-30 mm. 7.The method of claim 1, wherein: the step (3) is performed by using the third infrared laser beam to perform laser cladding on the second layer of the intermediate transition layer; the wavelength of the third infrared laser beam is 1000-1200 nm; and / or the power of the third infrared laser beam is 500-1000 W; and / or the spot diameter of the third infrared laser beam is 1-4 mm; and / or the laser scanning speed of the laser cladding using the third infrared laser beam is 10-50 mm / s; and / or the protective gas of the laser cladding using the third infrared laser beam is argon. 8.A high-hardness wear-resistant composite coating prepared by the method of any one of claims 1-7. 9.The high-hardness wear-resistant composite coating of claim 8, wherein: the hardness of the high-hardness wear-resistant composite coating is 500-600 HV; and / or the thickness of the high-hardness wear-resistant composite coating is 0.5-1 mm. 10.The application of the high-hardness wear-resistant composite coating prepared by the method of any one of claims 1-7 in wear-resistant equipment. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The wear rate of the high-hardness wear-resistant composite coating is 5x10 -7 mm³ / N·m~6.5x10 -7 mm³ / N·m. ​

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