Environment temperature response type chemical nickel plating coating and preparation method thereof

Abstract

The invention provides a chemical nickel-plating coating capable of dynamically adjusting the performance along with the change of the environment temperature and a preparation method of the chemical nickel-plating coating. The temperature response type material is introduced into the coating, so that the hardness and the corrosion resistance of the coating are remarkably improved under different temperature conditions, and the coating is particularly suitable for equipment protection in high-temperature, high-stress and corrosive environments. The coating has self-adaptive performance adjusting capability, and fills the technical blank of application of a traditional chemical nickel-plating coating in an extreme environment.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical nickel plating, and in particular to an intelligent coating capable of dynamically adjusting performance as ambient temperature changes, which is suitable for surface protection and function enhancement of equipment in extreme environments. Background Art

[0002] Chemical nickel coatings are widely used in the fields of machinery, electronics, and aerospace due to their excellent corrosion resistance, high hardness, and uniformity. However, traditional chemical nickel coatings have fixed properties and are difficult to adapt to the complex requirements of extreme environments (such as high temperature, high corrosion, or high stress). For example: 1. Under high temperature conditions, the hardness of ordinary chemical nickel coatings may decrease, resulting in insufficient wear resistance. 2. Under extreme temperature environments, the coating is prone to structural failure or corrosion.

[0003] In recent years, the application of responsive materials (such as shape memory alloys and thermosensitive polymers) in the field of smart coatings has attracted widespread attention. However, most of the current research focuses on organic material coatings, and there is still little research on responsiveness in metal coatings, especially in chemical plating technology. Therefore, it is of great significance to design a coating that combines chemical nickel plating with temperature-responsive materials. Summary of the invention

[0004] Aiming at the problems existing in the application of the existing chemical nickel plating coating, the invention provides an environmental temperature responsive chemical nickel plating coating and a preparation method thereof.

[0005] Implementation of the present invention: An environmental temperature responsive chemical nickel plating coating comprises a nickel-based material and a temperature responsive material dispersed in the nickel-based material, wherein the temperature responsive material is one or both of shape memory alloy particles and thermosensitive polymers. The present invention introduces a temperature responsive material into the nickel plating coating, so that the coating has the ability to dynamically adjust its performance with changes in ambient temperature, especially showing significantly enhanced hardness and corrosion resistance under high temperature conditions. This coating is particularly suitable for protection and functional enhancement in extreme environments such as aerospace, deep-sea exploration, and new energy equipment.

[0006] Preferably, the coating thickness is 8-25 um.

[0007] Preferably, the shape memory alloy particles are NiTi alloy particles. Further preferably, the particle size of the shape memory alloy particles is controlled within the range of 10-200 nm.

[0008] Preferably, the thermosensitive polymer is one of poly(N-isopropylacrylamide) (PNIPAM), polyethylene glycol methacrylate (PEGMA), and polyacrylic acid (PAA). Poly(N-isopropylacrylamide) (PNIPAM) changes from hydrophilicity to hydrophobicity at about 32 °C (LCST, lower critical solution temperature) and is a typical thermosensitive polymer. Polyethylene glycol methacrylate (PEGMA) has good thermosensitivity and controllable degradation properties. The thermosensitive response range of polyacrylic acid (PAA) can be adjusted by adding copolymers. Due to the strong thermosensitivity of thermosensitive polymers, they are easy to combine with nickel-based coatings and have good mechanical properties.

[0009] The method for preparing the above-mentioned environmental temperature responsive chemical nickel plating coating comprises the following steps: (1) preparing a plating solution: adding sodium hypophosphite, sodium citrate and polyethylene glycol to a nickel sulfate solution, and then adding shape memory alloy particles, fully mixing the components of the plating solution, and then ultrasonically dispersing the plating solution to obtain a chemical nickel plating solution; the plating solution components are: nickel sulfate: 20-30 g / L; sodium hypophosphite: 25-35 g / L; the weight of the temperature responsive material is 0.5-2% of the weight of the plating solution; sodium citrate (stabilizer): 8-10 g / L; polyethylene glycol 3-5 g / L; (2) Substrate pretreatment: first use a dilute acid solution to remove oxides and grease on the surface of the substrate; then activate the substrate by electrolysis or chemical methods to improve the surface affinity of the substrate; (3) Chemical plating: at 80-90°C, place the pretreated substrate in the plating solution, control the pH value of the plating solution between 4.5-5.0, and deposit for 60-120 minutes; (4) Post-treatment: anneal the plated component at 380-420°C for 20-40 minutes to fully combine the interface between the temperature-responsive material and the nickel-based coating, thereby obtaining an ambient temperature-responsive chemical nickel coating.

[0010] The present invention utilizes the martensite-austenite phase transition characteristics of shape memory alloys. At low temperatures, the shape memory alloy is in the martensite phase and has high plasticity. When the temperature rises above the phase transition temperature, the martensite transforms into the austenite phase, showing a significant increase in hardness and elastic modulus. Thermal deformation ability: During the temperature change process, the SMA particles can fill the microcracks inside the coating by fine-tuning the volume and reconstructing the shape, thereby improving the coating's ability to resist crack propagation. Thermal diffusion promotion: At high temperatures, the thermal conductivity of the SMA particles can improve the overall thermal stability of the coating and delay the occurrence of oxidation or corrosion reactions. The coating action mechanism of the present invention includes: (1) Hardness enhancement mechanism: When the ambient temperature rises to the phase transition temperature of the shape memory alloy (such as 300°C), the SMA particles transform from the martensite phase to the austenite phase, and the atomic arrangement inside the structure becomes denser, resulting in a significant increase in the hardness and elastic modulus of the particles. The high strength characteristics of the austenite phase are transmitted to the entire coating through the interface action, thereby enhancing the hardness and wear resistance of the coating at high temperatures. (2) Corrosion resistance enhancement mechanism: Under high temperature conditions, the phase change of SMA particles causes micro-scale shape adjustment, which can effectively close the micropores and microcracks in the coating and prevent further penetration of corrosive media (such as oxygen, moisture or salt spray). The high-temperature thermal diffusion effect at the interface between SMA particles and nickel-based coating accelerates the passivation reaction of nickel to form a dense NiO protective layer, significantly improving the corrosion resistance. (3) Self-healing performance: During repeated temperature cycles, the shape memory effect of SMA particles can repair microcracks caused by thermal expansion and contraction, and improve the fatigue resistance of the coating. The thermal expansion effect of SMA particles and the plastic fluidity of nickel-based coatings work together to adaptively bridge local defects at the coating interface. (4) Thermal management performance: The high thermal conductivity of SMA particles enables the coating to quickly dissipate heat in a high temperature environment, reducing the local heat accumulation effect, thereby slowing down the damage of high temperature to the interface between the substrate and the coating.

[0011] Thermosensitive polymers are temperature sensitive, and their physical or chemical properties (such as swelling, viscosity, phase state, etc.) change significantly when the temperature changes. The mechanism of action in the coating includes: (1) Regulation of corrosion resistance: Thermosensitive materials can swell or shrink at different temperatures. When the ambient temperature changes, the thermosensitive polymer may undergo a conformational transition, resulting in a change in the hydrophilicity or hydrophobicity of the coating surface. This change can regulate the corrosion resistance of the coating. At lower temperatures, the thermosensitive polymer may exhibit higher hydrophilicity, thereby enhancing the isolation of the coating from corrosive media in the environment; while at higher temperatures, the hydrophobicity of the material is enhanced, which helps to improve the corrosion resistance of the coating. (2) Adaptive performance regulation: Thermosensitive materials can adjust their structure and performance according to changes in ambient temperature. For example, in a high temperature environment, the phase change of the thermosensitive polymer will cause the microscopic porosity of the coating to change, thereby changing the sealing, corrosion resistance and mechanical properties of the coating. In this way, the coating can adjust its own performance under different temperature conditions through the responsiveness of the thermosensitive material, providing dynamic protection. (3) Thermal response and performance optimization: Similar to shape memory alloy particles, thermosensitive polymers also undergo structural changes when the temperature changes. This change can optimize the various properties of the coating. For example, as the temperature rises, the thermosensitive polymer may undergo a phase change, thereby changing the mechanical strength and wear resistance of the coating to adapt to different working environment conditions.

[0012] The mechanism of the interaction between thermosensitive polymers and shape memory alloy particles is based on the process of mutual cooperation of their physical or chemical response mechanisms when the temperature changes, which has multiple advantages such as adaptive performance adjustment, corrosion resistance, and wear resistance. This synergistic effect can significantly improve the stability and reliability of the coating under extreme environmental conditions. By introducing shape memory alloy particles and thermosensitive polymers into the chemical nickel plating coating, the coating can not only provide better protection in high temperature and high stress environments, but also automatically adjust its hardness, corrosion resistance and wear resistance according to temperature changes. This ability of adaptive performance adjustment enables the coating to continuously and effectively protect equipment under extreme environmental conditions, filling the technical gap of traditional chemical nickel plating coatings in high temperature, high stress and corrosive environments. This combined material system has broad application prospects, especially in aerospace, energy, marine engineering and other fields, and can provide more intelligent and lasting protection for key equipment.

[0013] By introducing shape memory alloy particles into the chemical nickel plating coating, the present invention realizes the dynamic adjustment of the coating performance with temperature changes, and has the following beneficial effects: 1. The hardness of the coating is significantly improved under high temperature environment, meeting the application requirements of high friction and high impact scenarios. 2. The corrosion resistance of the coating is enhanced, which can effectively prevent the corrosion of the substrate by high-temperature corrosive media. 3. The preparation process is simple, suitable for industrial production, and the coating thickness is uniform and highly stable. 4. It has a wide range of applications, especially suitable for surface protection and functional improvement in extreme environments. DETAILED DESCRIPTION

[0014] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0015] The coatings obtained in Examples 1-5 of the present invention were tested, and the information on various performance test standards and conditions is as follows: The hardness test standard is ASTM E384 (micro Vickers hardness test), and the equipment used is Wilson VH1202 micro hardness tester; the test conditions are: load 0.1 kgf, hold time 15 seconds.

[0016] The corrosion resistance test standard is ASTM B117 (neutral salt spray test), the equipment used is Q-FOG CCT salt spray test chamber, and the test conditions are using a 5% NaCl solution at a temperature of 35°C.

[0017] The wear resistance test standard is ASTM G99 (pin-on-disc friction and wear test), the equipment used is CETR UMTTribometer, and the test conditions are: load 5N, sliding speed 200mm / s, and friction distance 500m.

[0018] There is no reference standard for crack repair ability, so a method designed by the laboratory is used, with the size change after crack repair as the evaluation index. The equipment is an optical microscope (Olympus BX53) combined with image analysis software. Example

[0019] An environmental temperature responsive chemical nickel plating coating comprises a nickel-based material and a temperature responsive material dispersed in the nickel-based material, wherein the temperature responsive material is a temperature-sensitive polymer poly(N-isopropylacrylamide).

[0020] The preparation method of the above-mentioned environmental temperature responsive chemical nickel plating coating comprises the following steps: (1) preparation of plating solution: adding sodium hypophosphite, sodium citrate and polyethylene glycol to a nickel sulfate solution, and then adding a temperature-sensitive polymer poly (N-isopropylacrylamide), fully mixing the components of the plating solution, and then ultrasonically dispersing the plating solution to obtain a chemical nickel plating solution; the plating solution components are: nickel sulfate: 30 g / L; sodium hypophosphite: 35 g / L; the weight of the temperature responsive material is 0.5% of the weight of the plating solution; sodium citrate: 10 g / L; polyethylene glycol: 5 g / L; (2) substrate pretreatment: selecting a substrate 7 075 aluminum alloy (size 50mm×50mm×2mm) substrate, first use dilute sulfuric acid solution to remove oxides and grease on the substrate surface; then activate the substrate by electrolysis to improve the surface affinity of the substrate; (3) Chemical plating: at 85℃, put the pretreated substrate into the plating solution, control the pH value of the plating solution at 4.5, and deposit for 60 minutes; (4) Post-treatment: anneal the plated parts at 400℃ for 30 minutes to fully combine the interface between the shape memory particles and the nickel-based coating, that is, obtain an ambient temperature responsive chemical nickel coating, and obtain a nickel coating with a thickness of 8um.

[0021] The hardness test of the coating obtained in this embodiment shows that the coating hardness increases from 580 HV at room temperature to 720 HV at 40°C, indicating the dynamic enhancement effect of the thermosensitive polymer on high temperature hardness. Corrosion resistance: The corrosion resistance time in the salt spray test is up to 400 hours. From the performance test results, it can be seen that the nickel-plated coating obtained in this embodiment has good high temperature hardness enhancement performance and good corrosion resistance. Example

[0022] An ambient temperature responsive chemical nickel plating coating comprises a nickel-based material and a temperature responsive material dispersed in the nickel-based material, wherein the temperature responsive material is a mixture of shape memory alloy particles and a temperature sensitive polymer; the shape memory alloy particles are NiTi particles with a particle size of 10-50 nm, and the temperature sensitive polymer is poly(N-isopropylacrylamide).

[0023] The above-mentioned method for preparing an environmental temperature responsive chemical nickel plating coating comprises the following steps: (1) preparing a plating solution: adding sodium hypophosphite, sodium citrate and polyethylene glycol to a nickel sulfate solution, then adding a temperature responsive material, fully mixing the components of the plating solution, and then ultrasonically dispersing the plating solution to obtain a chemical nickel plating solution; the plating solution components are: nickel sulfate: 20 g / L; sodium hypophosphite: 25 g / L; the weight of the temperature responsive material is 1.5% of the weight of the plating solution, wherein the weight of the NiTi particles is 1% of the weight of the plating solution, and the weight of the temperature sensitive polymer is 0.5% of the weight of the plating solution; sodium citrate: 10 g / L; polyethylene glycol: 5 g / L L; (2) Substrate pretreatment: 300M steel (size 50mm×50mm×3mm) was selected as the substrate, and a dilute sulfuric acid solution was first used to remove oxides and grease on the substrate surface; then the substrate was activated by electrolysis to improve the surface affinity of the substrate; (3) Chemical plating: at 90°C, the pretreated substrate was placed in the plating solution, the pH value of the plating solution was controlled at 5.0, and the deposition was performed for 90 minutes; (4) Post-treatment: The plated component after chemical plating was annealed at 380°C for 40 minutes to fully combine the interface between the shape memory particles and the nickel-based coating, that is, to obtain an ambient temperature responsive chemical nickel coating, and the thickness of the nickel plating coating was 12um.

[0024] The coating obtained in this embodiment was tested, and the results were: Coating hardness: increased from 600 HV at room temperature to 850 HV at 300 °C, indicating the dynamic enhancement effect of temperature-responsive materials on high-temperature hardness.

[0025] Coating self-healing ability: Cracks in the field of view are obviously repaired and healed, and the crack width is reduced by 80%.

[0026] Coating wear resistance: The friction coefficient is reduced from 0.20 of traditional coating to 0.15, and the wear resistance is improved by about 25%.

[0027] It can be seen from the performance test results that the nickel-plated coating obtained in this embodiment has excellent high-temperature hardness strengthening hydrogen energy, good self-repairing property and excellent wear resistance. Example

[0028] An environmental temperature responsive chemical nickel plating coating comprises a nickel-based material and a temperature responsive material dispersed in the nickel-based material, wherein the temperature responsive material is a mixture of shape memory alloy particles and a temperature sensitive polymer; the shape memory alloy particles are NiTi particles with a particle size of 10-50 nm, and the temperature sensitive polymer is polyethylene glycol methacrylate.

[0029] The above-mentioned method for preparing an environmental temperature responsive chemical nickel plating coating comprises the following steps: (1) preparing a plating solution: adding sodium hypophosphite, sodium citrate and polyethylene glycol to a nickel sulfate solution, then adding a temperature responsive material, fully mixing the components of the plating solution, and then ultrasonically dispersing the plating solution to obtain a chemical nickel plating solution; the plating solution components are: nickel sulfate: 30 g / L; sodium hypophosphite: 35 g / L; the weight of the temperature responsive material is 2.0% of the weight of the plating solution, of which the weight of the NiTi particles is 1.7% of the weight of the plating solution, and the weight of the temperature sensitive polymer is 0.3% of the weight of the plating solution; sodium citrate: 8 g / L; polyethylene glycol: 3 g / L ; (2) Substrate pretreatment: 7075 aluminum alloy (size 60mm×40mm×2mm) was selected as the substrate, and a dilute hydrochloric acid solution was first used to remove oxides and grease on the substrate surface; then the substrate was activated by electrolysis to improve the surface affinity of the substrate; (3) Chemical plating: at 85°C, the pretreated substrate was placed in the plating solution, the pH value of the plating solution was controlled at 4.8, and the deposition was performed for 70 minutes; (4) Post-treatment: The plated component after chemical plating was annealed at 420°C for 20 minutes to fully combine the interface between the shape memory particles and the nickel-based coating, that is, to obtain an ambient temperature responsive chemical nickel coating, and the thickness of the nickel coating was 10um.

[0030] The test results are as follows: Corrosion resistance: Salt spray test time 500 hours. Hardness: The hardness is increased from 580 HV at room temperature to 750 HV at 40°C. From the performance test results, it can be seen that the nickel-plated coating obtained in this embodiment has excellent corrosion resistance and good high-temperature hardness strengthening performance. Example

[0031] An environmental temperature responsive chemical nickel plating coating comprises a nickel-based material and a temperature responsive material dispersed in the nickel-based material, wherein the temperature responsive material is a mixture of shape memory alloy particles and a temperature sensitive polymer; the shape memory alloy particles are NiTi particles with a particle size of 100-200 nm, and the temperature sensitive polymer is polyacrylic acid.

[0032] The above-mentioned method for preparing an environmental temperature responsive chemical nickel plating coating comprises the following steps: (1) preparing a plating solution: adding sodium hypophosphite, sodium citrate and polyethylene glycol to a nickel sulfate solution, then adding a temperature responsive material, fully mixing the components of the plating solution, and then ultrasonically dispersing the plating solution to obtain a chemical nickel plating solution; the plating solution components are: nickel sulfate: 28 g / L; sodium hypophosphite: 35 g / L; the weight of the temperature responsive material is 1.5% of the weight of the plating solution, wherein the weight of the NiTi particles is 1.0% of the weight of the plating solution, and the weight of the temperature sensitive polymer is 0.5% of the weight of the plating solution; sodium citrate: 10 g / L; polyethylene glycol: 3 g / L; (2) Substrate pretreatment: 300M steel (size 70mm×50mm×2mm) is used as the substrate. First, a dilute hydrochloric acid solution is used to remove oxides and grease on the substrate surface; then the substrate is activated by electrolysis to improve the surface affinity of the substrate; (3) Chemical plating: at 90°C, the pretreated substrate is placed in the plating solution, the pH value of the plating solution is controlled at 4.6, and the deposition is carried out for 120 minutes; (4) Post-treatment: The plated component after chemical plating is annealed at 420°C for 20 minutes to fully combine the interface between the shape memory particles and the nickel-based coating, that is, to obtain an ambient temperature responsive chemical nickel coating, and the thickness of the nickel plating coating is 20um.

[0033] The test results are as follows: High temperature hardness: The hardness is 620HV at room temperature, and the hardness is increased to 900HV at 300°C. Corrosion resistance: No obvious corrosion after 600h of salt spray test. It can be seen from the performance test results that the nickel-plated coating obtained in this embodiment has excellent high temperature hardness strengthening performance and corrosion resistance. Example

[0034] An environmental temperature responsive chemical nickel plating coating comprises a nickel-based material and a temperature responsive material dispersed in the nickel-based material, wherein the temperature responsive material is polyethylene glycol methacrylate.

[0035] The preparation method of the above-mentioned environmental temperature responsive chemical nickel plating coating comprises the following steps: (1) preparation of plating solution: adding sodium hypophosphite, sodium citrate and polyethylene glycol to a nickel sulfate solution, then adding a temperature responsive material, fully mixing the components of the plating solution, and then ultrasonically dispersing the plating solution to obtain a chemical nickel plating solution; the plating solution components are: nickel sulfate: 28 g / L; sodium hypophosphite: 35 g / L; the weight of the temperature responsive material is 1.5% of the weight of the plating solution; sodium citrate: 10 g / L; polyethylene glycol: 3 g / L; (2) substrate pretreatment: Ti-6Al-4V titanium alloy Gold (size 50mm×30mm×1mm) is used as the substrate. A dilute hydrochloric acid solution is first used to remove oxides and grease on the substrate surface. The substrate is then activated by electrolysis to improve the surface affinity of the substrate. (3) Chemical plating: At 90°C, the pretreated substrate is placed in the plating solution, the pH value of the plating solution is controlled at 4.5, and the deposition is carried out for 100 minutes. (4) Post-treatment: The plated component after chemical plating is annealed at 400°C for 35 minutes to fully combine the interface between the shape memory particles and the nickel-based coating, that is, to obtain an ambient temperature responsive chemical nickel coating, and the thickness of the nickel coating is 20um.

[0036] The test results are as follows: Wear resistance: The friction coefficient is 0.14. Corrosion resistance: The corrosion rate is 0.015 mm / year. It can be seen from the performance test results that the nickel-plated coating obtained in this embodiment has excellent wear resistance and corrosion resistance. Example

[0037] An environmental temperature responsive chemical nickel plating coating comprises a nickel-based material and a temperature responsive material dispersed in the nickel-based material. The temperature responsive material is NiTi particles with a particle size of 50-100 nm.

[0038] The above-mentioned method for preparing an environmental temperature responsive chemical nickel plating coating comprises the following steps: (1) preparing a plating solution: adding sodium hypophosphite, sodium citrate and polyethylene glycol to a nickel sulfate solution, then adding a temperature responsive material, fully mixing the components of the plating solution, and then ultrasonically dispersing the plating solution to obtain a chemical nickel plating solution; the plating solution components are: nickel sulfate: 20 g / L; sodium hypophosphite: 25 g / L; the weight of the temperature responsive material is 0.8% of the weight of the plating solution; sodium citrate: 10 g / L; polyethylene glycol: 3 g / L; (2) substrate pretreatment: 7075 aluminum alloy ( (2) A pre-treated substrate (60 mm × 40 mm × 2 mm in size) was used as the substrate. A dilute sulfuric acid solution was first used to remove oxides and grease on the substrate surface. The substrate was then activated by electrolysis to improve the surface affinity of the substrate. (3) Chemical plating: at 85°C, the pre-treated substrate was placed in the plating solution, the pH value of the plating solution was controlled at 5.0, and the deposition was performed for 120 min. (4) Post-treatment: The plated component was annealed at 400°C for 35 min to fully combine the shape memory particles with the interface of the nickel-based coating, thereby obtaining an ambient temperature responsive chemical nickel coating. The thickness of the nickel coating was 25 μm.

[0039] The test results are as follows: Corrosion resistance: The corrosion resistance time of the salt spray test is increased to 800 hours. High temperature performance: The hardness is 860 HV at 300°C. From the performance test results, it can be seen that the nickel plating layer obtained in this embodiment has excellent corrosion resistance and high temperature hardness strengthening performance. Example

[0040] An environmental temperature responsive chemical nickel plating coating comprises a nickel-based material and a temperature responsive material dispersed in the nickel-based material, wherein the temperature responsive material is polyacrylic acid.

[0041] The preparation method of the above-mentioned environmental temperature responsive chemical nickel plating coating comprises the following steps: (1) preparing a plating solution: adding sodium hypophosphite, sodium citrate and polyethylene glycol to a nickel sulfate solution, then adding a temperature responsive material, fully mixing the components of the plating solution, and then ultrasonically dispersing the plating solution to obtain a chemical nickel plating solution; the plating solution components are: nickel sulfate: 30 g / L; sodium hypophosphite: 30 g / L; the weight of the temperature responsive material is 1.2% of the weight of the plating solution; sodium citrate: 9 g / L; polyethylene glycol: 4 g / L; (2) substrate pretreatment: 7075 aluminum alloy (size: 200 g / L) (50 mm × 50 mm × 2 mm) as the substrate, first use a dilute hydrochloric acid solution to remove oxides and grease on the substrate surface; then activate the substrate by electrolysis to improve the surface affinity of the substrate; (3) Chemical plating: at 80 ° C, put the pretreated substrate into the plating solution, control the pH value of the plating solution at 4.5, and deposit for 90 minutes; (4) Post-treatment: anneal the plated piece at 400 ° C for 30 minutes to fully combine the interface between the shape memory particles and the nickel-based coating, that is, obtain an ambient temperature responsive chemical nickel coating, and the thickness of the nickel coating is 12 um.

[0042] The test results are as follows: Crack repair: Under the temperature cycle (room temperature to 300°C, 5 cycles), the crack width is reduced from 10um to 2um. Hardness: The hardness is maintained at 870HV at 300°C. From the performance test results, it can be seen that the nickel-plated coating obtained in this embodiment has excellent crack repair and high temperature hardness strengthening performance.

Claims

1. An environmental temperature responsive chemical nickel plating coating, characterized in that: It comprises a nickel-based material and a temperature-responsive material dispersed in the nickel-based material. The temperature-responsive material is one or both of shape memory alloy particles and temperature-sensitive polymers.

2. The environmental temperature responsive chemical nickel plating coating according to claim 1, characterized in that: The coating thickness is 8-25um.

3. According to the environmental temperature responsive chemical nickel plating coating according to claim 1, the shape memory alloy particles are NiTi alloy particles.

4. The environmental temperature responsive chemical nickel plating coating according to claim 2, characterized in that: The particle size of the shape memory alloy particles is controlled within the range of 10-200 nm.

5. The environmental temperature responsive chemical nickel plating coating according to claim 1, wherein the temperature sensitive polymer is one of poly (N-isopropylacrylamide), polyethylene glycol methacrylate, and polyacrylic acid.

6. A method for preparing an environmental temperature responsive chemical nickel plating coating according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: (1) preparing a plating solution: adding sodium hypophosphite, sodium citrate and polyethylene glycol to a nickel sulfate solution, and then adding a temperature-responsive material, fully mixing the components of the plating solution, and then ultrasonically dispersing the plating solution to obtain a chemical nickel plating solution; the plating solution components are: nickel sulfate: 20-30 g / L; sodium hypophosphite: 25-35 g / L; the weight of the temperature-responsive material is 0.5-2% of the weight of the plating solution; sodium citrate: 8-10 g / L; and polyethylene glycol: 3-5 g / L; (2) pretreatment of the substrate: first using a dilute acid The solution removes oxides and grease on the surface of the substrate; then the substrate is activated by electrolysis or chemical methods to improve the surface affinity of the substrate; (3) Chemical plating: at 80-90°C, the pretreated substrate is placed in the plating solution, the pH value of the plating solution is controlled between 4.5-5.0, and the deposition is carried out for 60-120 minutes; (4) Post-treatment: the plated component after chemical plating is annealed at 380-420°C for 20-40 minutes to fully combine the interface between the temperature-responsive material and the nickel-based coating, thereby obtaining an ambient temperature-responsive chemical nickel coating.