A cold spraying method for high-content micro-oxidation-electroplated nickel-coated silicon carbide particles reinforced aluminum-based composite coating

Abstract

A cold spraying method for a high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating relates to a cold spraying method for an aluminum-based composite coating. Cold spraying method: micro-oxidation treatment of silicon carbide particles under atmospheric conditions, electroplating a nickel layer on the surface, low-energy ball milling with aluminum powder, and finally cold spraying. The present invention uses high-temperature oxidation and electroplating technology to plate nickel on the surface of silicon carbide powder particles to obtain a core-shell structure powder composed of a reinforcing phase silicon carbide particle and a ductile metal nickel shell, thereby avoiding the poor bonding between the reinforcing phase silicon carbide and the matrix metal aluminum and the structural defects caused by the collision and fragmentation of silicon carbide particles, increasing the deposition rate, avoiding harmful microstructural changes or oxidation, reducing thermal effects, improving the particle-particle and particle-matrix bonding strength, the structural uniformity inside the coating, and reducing the structural defects caused by silicon carbide fragmentation, and having excellent antioxidant properties, corrosion resistance and wear resistance.

Description

Technical Field

[0001] The invention relates to a cold spraying method for an aluminum-based composite coating. Background Art

[0002] Aluminum-based (SiCp / Al) composite coatings reinforced with high silicon carbide particles (volume fractions exceeding 40%) exhibit exceptional performance characteristics (such as high thermal conductivity, low material density, and high wear resistance), making them the most widely used composite coating in the aerospace industry. However, technological advancements and changes in the material's service environment are placing higher demands on the performance of SiCp / Al composite coatings. Conventional SiCp / Al composite coatings are no longer able to meet these requirements, necessitating the development of higher-performance SiCp / Al composite coatings.

[0003] Although high-content SiCp / Al composite coatings have excellent wear resistance, their corrosion resistance varies. As the SiCp content increases, high-content SiCp will produce a denser coating due to the compaction effect, so the crack propagation speed in the substrate is slower, and the SiCp density in the coating will also delay the corrosion from extending through the cracks. On the other hand, the current research on SiCp / Al composite coatings is slow. Comprehensive analysis mainly has the following reasons: (1) SiCp has poor uniformity in the aluminum matrix, and many existing methods also make it difficult to disperse it evenly. Moreover, during the cold spraying process, some powder particles are lost due to the reaction force of collision, and the amount of SiCp actually retained is far from the theoretical value. (2) The interface wettability between SiCp and Al matrix is poor, resulting in poor load transfer capacity of SiC and interface fracture. Interface fracture is considered to be the main reason for the brittleness of high volume fraction SiCp / Al composite coatings, because interface fracture provides a channel for crack propagation during deformation without the intervention of matrix metal, and even SiCp forms a crack source at the interface due to collision fragmentation. The bonding quality between particles in the cold spraying process directly determines the conductivity, physical isolation performance, bonding strength and mechanical properties of the deposit. Therefore, modifying the particle interface characteristics and effectively regulating the bonding between particles are the prerequisites for achieving performance control of cold spray coatings, repairing and remanufacturing metal components and additive manufacturing components. Therefore, introducing surface treatment of SiCp reinforcement particles to improve its wetting effect as a particle reinforcement in the metal, inhibiting interface fracture by strengthening interface bonding, and thus improving the protective function of the magnesium alloy surface is an effective means to improve its service life.

[0004] For SiC particle-reinforced aluminum-based composites, the technology for coating the bulk material surface is now well established, including electroless plating on the surface of high-volume-fraction SiC particle-reinforced aluminum-based composites and sol-gel coating on the surface of SiC particle-reinforced aluminum-based composites. However, due to the relatively large specific surface area and surface energy of the microparticles, the microparticles easily agglomerate, and the very small radius of curvature, depositing metal films on the surface of SiC particles is quite difficult. Currently, thermal reduction nickel plating and electroless nickel plating on SiC particles are the main methods used, but their efficiency is relatively low. Furthermore, for the preparation of silicon carbide particle-reinforced aluminum-based composite materials, the methods for preparing silicon carbide particle-reinforced aluminum-based composite coatings include thermal spraying, laser cladding, and chemical vapor deposition. The extremely high process temperatures of thermal spraying and laser cladding present problems related to the heterogeneity, porosity, and low wettability of the matrix particles. For example, due to the formation of Al4C3, high-temperature processing of the Al-SiC system is limited because the needle-shaped crystals produce crack initiation zones due to their brittleness, resulting in Al4C3 having poor mechanical and corrosion properties. Among these methods, the coating thickness prepared by chemical vapor deposition is limited, usually below tens of microns, and the coating deposition rate is also relatively slow. Summary of the Invention

[0005] In order to address the deficiencies in the above-mentioned prior art, the present invention discloses a method for preparing a cold-sprayed high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating. The present invention uses high-temperature oxidation and electroplating technology to plate nickel on the surface of silicon carbide powder particles to obtain a core-shell structure powder composed of a reinforcing phase silicon carbide particle and a shell of ductile metal nickel. 40wt.% micro-oxidation-electroplated nickel-coated silicon carbide particles and 60wt.% aluminum powder are subjected to an optimized ball milling process to obtain an aluminum-based composite powder with uniform distribution of nickel-coated silicon carbide particles, thereby avoiding the poor bonding between the reinforcing phase silicon carbide and the matrix metal aluminum and the structural defects caused by the collision and fragmentation of silicon carbide particles. Based on the excellent deposition rate of cold spraying technology, the ability to avoid harmful microstructural changes or oxidation, and the reduction of thermal effects, the particle-particle and particle-matrix bonding strength, the structural uniformity within the coating, and the reduction of structural defects caused by silicon carbide fragmentation can be improved, thereby facilitating the acquisition of a high-content nickel-coated silicon carbide particle reinforced aluminum-based composite coating with excellent antioxidant, corrosion resistance, and wear resistance.

[0006] The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating of the present invention is carried out by the following steps:

[0007] Step 1: Under atmospheric conditions, the silicon carbide particles are subjected to a micro-oxidation treatment in a muffle furnace to in-situ grow a nano-amorphous silicon dioxide layer on the surface of the silicon carbide particles to obtain nano-silicon dioxide-coated silicon carbide particles;

[0008] The micro-oxidation treatment comprises the following steps: first, ultrasonically cleaning the silicon carbide particles with anhydrous ethanol for 20-30 minutes, then ultrasonically cleaning them with deionized water for 10-15 minutes, and finally drying them; spreading the cleaned silicon carbide particles on a crucible and placing them in a muffle furnace, heating the muffle furnace to 1100-1200° C. and then keeping the temperature for 4-6 hours, replenishing air into the muffle furnace every 0.5-1 hour, and finally cooling the crucible;

[0009] Step 2: Electroplating a nickel layer on the surface of the nano-silicon dioxide-coated silicon carbide particles to obtain slightly oxidized-electroplated nickel-coated silicon carbide particles;

[0010] Step 3: Using a ball mill, the slightly oxidized and nickel-plated silicon carbide particles and the aluminum powder are subjected to low-energy ball milling to uniformly distribute the slightly oxidized and nickel-plated silicon carbide particles in the aluminum powder to obtain a mixed powder;

[0011] The mass ratio of the aluminum powder to the slightly oxidized-electroplated nickel-coated silicon carbide particles is 1-2:3;

[0012] The low-energy ball milling process comprises: mixing aluminum powder and slightly oxidized-electroplated nickel-coated silicon carbide particles and then loading the mixture into a ball mill; evacuating the ball mill and then introducing argon gas; performing dry milling with a ball-to-material ratio of 3-4:1 and a ball milling speed of 150-200 rpm for 2-4 hours, with the ball mill rotating in one direction and stopping for 5-10 minutes every 0.5-1 hour of milling to obtain a mixed powder;

[0013] Step 4: spraying the mixed powder obtained in step 3 onto the substrate by cold spraying to obtain a high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating;

[0014] The cold spraying process comprises: ultrasonically cleaning the spray substrate with anhydrous ethanol for 5-60 minutes, taking it out and drying it, then sandblasting the surface to be sprayed, and cleaning the surface to be sprayed with an air gun after the treatment; loading the mixed powder obtained in step 3 into a powder feeder, fixing the substrate and cold spraying it with a spray gun, using argon as the powder feeding gas, the cold spraying trajectory is S-shaped, the spraying trajectory line spacing is 2-3mm, the spraying beam is at 90 degrees to the surface to be sprayed, the gun speed is 150-200mm / s, the vertical distance between the gun muzzle and the surface to be sprayed is 30-35mm, the chamber pressure is 3.5-4MPa, the chamber gas temperature is 550-600℃, and the spraying is repeated several times according to the required coating thickness;

[0015] The mass fraction of Ni in the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating obtained in step 4 is 2.46-5.77%.

[0016] Principles and beneficial effects of the present invention:

[0017] 1. The present invention adopts a high-temperature micro-oxidation method to obtain nano-amorphous silicon dioxide-coated silicon carbide particles, which reduces the surface energy of the microparticles and gives the silicon carbide particles a certain electrical conductivity, which can effectively increase the adhesion of silicon carbide particles to metallic nickel, thereby improving the bonding strength between silicon carbide and the nickel layer after nickel plating, and avoiding the core-shell separation of silicon carbide particles and the nickel layer during the subsequent cold spraying process.

[0018] 2. The present invention uses electroplating technology to plate nickel on the surface of silicon carbide particles. Due to the effect of micro-oxidation in the early stage, the problem of silicon carbide ceramic particles being difficult to deposit due to their non-conductivity is solved. As the electroplating time increases, the roughness of the nickel on the surface of the silicon carbide particles increases, the coating area is larger, and the bonding strength between nickel and silicon carbide particles is high, thereby effectively avoiding defects such as cracks caused by the collision and fragmentation of silicon carbide in the subsequent coating. In addition, nickel is a common metal element with good affinity for aluminum, which can improve the wettability of metal-based composite materials and will not produce interface pollutants, defects or any other dispersions. In cold-sprayed silicon carbide particle-reinforced aluminum-based composite coatings, nickel can be used as an effective surface coating or additive to optimize the bonding interface between silicon carbide particles and the aluminum matrix, and improve the performance of the composite material, achieving better performance and application value.

[0019] 3. The present invention adopts cold spraying technology, which can deposit coatings at a lower temperature (usually hundreds of degrees Celsius) and a higher deposition rate (usually the coating deposition can reach a thickness of millimeters per minute). The temperature of the spraying process is much lower than the melting point of aluminum. The mixed powder is affected by heat, and no phase change occurs during the spraying process, which greatly suppresses the generation of thermal stress and thermal defects in the coating. It has excellent microstructure and mechanical properties. The thickness of the prepared coating is between tens of microns and tens of millimeters, and the bonding strength between the coating and the substrate is high, thereby obtaining an aluminum-based composite coating with excellent antioxidant, corrosion resistance and wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is an SEM image of the nano-silicon dioxide-coated silicon carbide particles obtained in step 1 of Example 1;

[0021] Figure 2 This is the XPS graph of the nano-silicon dioxide-coated silicon carbide particles obtained in step 1 of Example 1;

[0022] Figure 3 This is an SEM image of the slightly oxidized-electroplated nickel-coated silicon carbide particles obtained in step 2 of Example 1;

[0023] Figure 4 This is the nickel element distribution diagram of the slightly oxidized-electroplated nickel-coated silicon carbide particles obtained in step 2 of Example 1;

[0024] Figure 5 This is an SEM image of the slightly oxidized-electroplated nickel-coated silicon carbide particles obtained in step 2 of Example 2;

[0025] Figure 6 This is the nickel element distribution diagram of the slightly oxidized-electroplated nickel-coated silicon carbide particles obtained in step 2 of Example 2;

[0026] Figure 7 This is an SEM image of the slightly oxidized-electroplated nickel-coated silicon carbide particles obtained in step 2 of Example 3;

[0027] Figure 8 This is the nickel element distribution diagram of the slightly oxidized-electroplated nickel-coated silicon carbide particles obtained in step 2 of Example 3;

[0028] Figure 9 This is a cross-sectional morphology of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle-reinforced aluminum-based composite coating obtained by cold spraying in step 4 of Example 1;

[0029] Figure 10 This is a cross-sectional morphology of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle-reinforced aluminum-based composite coating obtained by cold spraying in step 4 of Example 2;

[0030] Figure 11 This is a morphology of silicon carbide particles in the aluminum-based composite coating reinforced with high-content micro-oxidation-electroplated nickel-coated silicon carbide particles obtained by cold spraying in step 4 of Example 3. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any reasonable combination of the specific implementation methods.

[0032] Specific embodiment 1: The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating of this embodiment is carried out in the following steps:

[0033] Step 1: Under atmospheric conditions, the silicon carbide particles are subjected to a micro-oxidation treatment in a muffle furnace to in-situ grow a nano-amorphous silicon dioxide layer on the surface of the silicon carbide particles to obtain nano-silicon dioxide-coated silicon carbide particles;

[0034] The micro-oxidation treatment comprises the following steps: first, ultrasonically cleaning the silicon carbide particles with anhydrous ethanol for 20-30 minutes, then ultrasonically cleaning them with deionized water for 10-15 minutes, and finally drying them; spreading the cleaned silicon carbide particles on a crucible and placing them in a muffle furnace, heating the muffle furnace to 1100° C. and then keeping the temperature for 6 hours, replenishing air into the muffle furnace every hour, and finally cooling the crucible;

[0035] Step 2: Electroplating a nickel layer on the surface of the nano-silicon dioxide-coated silicon carbide particles to obtain slightly oxidized-electroplated nickel-coated silicon carbide particles;

[0036] Step 3: Using a ball mill, the slightly oxidized and nickel-plated silicon carbide particles and the aluminum powder are subjected to low-energy ball milling to uniformly distribute the slightly oxidized and nickel-plated silicon carbide particles in the aluminum powder to obtain a mixed powder;

[0037] The mass ratio of the aluminum powder to the slightly oxidized-electroplated nickel-coated silicon carbide particles and the nickel-coated silicon carbide particles is 2:3;

[0038] The low-energy ball milling process comprises: mixing aluminum powder and micro-oxidized-electroplated nickel-coated silicon carbide particles and then loading them into a ball mill; evacuating the ball mill and then introducing argon gas; performing dry milling with a ball-to-material ratio of 3:1 and a ball milling speed of 150-200 rpm for 2-4 hours, with the ball mill rotating in one direction and stopping for 5-10 minutes after every hour of milling to obtain a mixed powder;

[0039] Step 4: spraying the mixed powder obtained in step 3 onto the substrate by cold spraying to obtain a high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating;

[0040] The cold spraying process comprises: ultrasonically cleaning the spray substrate with anhydrous ethanol for 5-60 minutes, taking it out and drying it, then sandblasting the surface to be sprayed, and cleaning the surface to be sprayed with an air gun after the treatment; loading the mixed powder obtained in step 3 into a powder feeder, fixing the substrate and cold spraying it with a spray gun, using argon as the powder feeding gas, the cold spraying trajectory is S-shaped, the spraying trajectory line spacing is 2mm, the spraying beam is at 90° to the surface to be sprayed, the gun speed is 150-200mm / s, the vertical distance between the gun muzzle and the surface to be sprayed is 30mm, the chamber pressure is 4MPa, the chamber gas temperature is 550-600℃, and the spraying is performed several times according to the required coating thickness;

[0041] The mass fraction of Ni in the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating obtained in step 4 is 2.46-5.77%.

[0042] This embodiment has the following beneficial effects:

[0043] 1. This embodiment uses high-temperature micro-oxidation to obtain nano-amorphous silicon dioxide-coated silicon carbide particles, which reduces the surface energy of the microparticles and gives the silicon carbide particles a certain degree of conductivity. It can effectively increase the adhesion of silicon carbide particles to metallic nickel, thereby improving the bonding strength between silicon carbide and the nickel layer after nickel plating, and avoiding the core-shell separation of silicon carbide particles and the nickel layer during the subsequent cold spraying process.

[0044] 2. This embodiment uses electroplating technology to plate nickel on the surface of silicon carbide particles. Due to the effect of micro-oxidation in the early stage, the problem of silicon carbide ceramic particles being difficult to deposit due to their non-conductivity is solved. As the electroplating time increases, the roughness of the nickel on the surface of the silicon carbide particles increases, the coating area is larger, and the bonding strength between nickel and silicon carbide particles is high, thereby effectively avoiding defects such as cracks caused by the collision and fragmentation of silicon carbide in subsequent coatings. In addition, nickel is a common metal element with good affinity for aluminum, which can improve the wettability of metal-based composite materials and will not produce interface contaminants, defects or any other dispersions. In cold-sprayed silicon carbide particle-reinforced aluminum-based composite coatings, nickel can be used as an effective surface coating or additive to optimize the bonding interface between silicon carbide particles and the aluminum matrix, and improve the performance of the composite material, achieving better performance and application value.

[0045] 3. This embodiment adopts cold spraying technology, which can deposit the coating at a lower temperature (usually hundreds of degrees Celsius) and a higher deposition rate (usually the coating deposition can reach a thickness of millimeters per minute). The temperature of the spraying process is much lower than the melting point of aluminum. The mixed powder is affected by heat, and no phase change occurs during the spraying process, which greatly suppresses the generation of thermal stress and thermal defects in the coating. It has excellent microstructure and mechanical properties. The thickness of the prepared coating is between tens of microns and tens of millimeters, and the bonding strength between the coating and the substrate is high, thereby obtaining an aluminum-based composite coating with excellent antioxidant, corrosion resistance and wear resistance.

[0046] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that: the micro-oxidation treatment described in step 1 includes the following steps: first, the silicon carbide particles are ultrasonically cleaned with anhydrous ethanol for 20 minutes, then ultrasonically cleaned with deionized water for 15 minutes, and finally dried; the cleaned silicon carbide particles are spread flat on a crucible and placed in a muffle furnace, the muffle furnace is heated to 1100°C and kept warm for 6 hours, air is added to the muffle furnace every 1 hour, and finally cooled with the furnace.

[0047] Specific embodiment three: This embodiment differs from specific embodiment one or two in that: the micro-oxidation treatment described in step one includes the following steps: first, the silicon carbide particles are ultrasonically cleaned with anhydrous ethanol for 20 minutes, then ultrasonically cleaned with deionized water for 15 minutes, and finally dried; the cleaned silicon carbide particles are spread flat on a crucible and placed in a muffle furnace, the muffle furnace is heated to 1100°C and kept warm for 6 hours, air is added to the muffle furnace every 1 hour, and finally cooled with the furnace.

[0048] Specific embodiment 4: This embodiment differs from any one of specific embodiments 1 to 3 in that: the purity of the silicon carbide particles in step 1 is 99.9%, the particles are irregular in shape, and the particle size is 55-65 μm.

[0049] Specific embodiment five: This embodiment differs from any one of specific embodiments one to four in that: the electroplating process described in step two is: current density: 1.0-1.4A / dm2, temperature: 50-60°C, time: 1h, pH: 3.6-4.8, the temperature of the plating solution does not exceed 95°C, and the plating solution is stirred once every 5 minutes during the electroplating process to ensure the uniformity of the nickel layer on the surface of the silicon carbide particles. After the nickel electroplating is completed, the micro-oxidation-electroplated nickel-coated silicon carbide particles are separated and ultrasonically cleaned with deionized water for 20-30 minutes, and then dried.

[0050] Specific embodiment six: This embodiment differs from specific embodiment five in that the composition of the electroplating solution is: 450 g / L nickel sulfamate, 40 g / L boric acid, 20 g / L nickel bromide, and 0.2 g / L sodium lauryl sulfate.

[0051] Specific embodiment seven: This embodiment differs from any one of specific embodiments one to six in that: the purity of the aluminum powder in step three is 99.9%, the particles are spherical, and the particle size is 20-35 μm.

[0052] Specific embodiment eight: This embodiment differs from any one of specific embodiments one to seven in that: the ball mill in step three is a planetary ball mill.

[0053] Specific embodiment nine: This embodiment differs from any one of specific embodiments one to eight in that: the process of low-energy ball milling described in step three is: aluminum powder and micro-oxidation-electroplated nickel-coated silicon carbide particles are mixed and then loaded into a ball mill; the ball mill is evacuated and then argon gas is introduced. The ball milling process is dry milling, the ball-to-material ratio is 3:1, the ball milling speed is 200r / min, the ball milling is carried out for 4h, the ball milling jar rotates in one direction, and stops for 10min after every 1h of ball milling to obtain a mixed powder.

[0054] Specific embodiment ten: This embodiment differs from any one of specific embodiments one to nine in that: the cold spraying process described in step four is: ultrasonically clean the spraying substrate with anhydrous ethanol for 30 minutes, take it out and dry it, then sandblast the surface to be sprayed, and clean the surface to be sprayed with an air gun after the treatment; the mixed powder obtained in step three is loaded into a powder feeder, and the substrate is fixed and cold sprayed using a spray gun. Argon is used as the powder feeding gas, the cold spraying trajectory is S-shaped, the spraying trajectory line spacing is 2mm, the spray beam is 90° to the surface to be sprayed, the gun speed is 200mm / s, the vertical distance between the muzzle and the surface to be sprayed is 30mm, the chamber air pressure is 4MPa, the chamber gas temperature is 600℃, and spraying is performed 5 times according to the required coating thickness.

[0055] Example 1:

[0056] The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating of this embodiment is carried out as follows:

[0057] Step 1: Under atmospheric conditions, the silicon carbide particles are subjected to a micro-oxidation treatment in a muffle furnace to in-situ grow a nano-amorphous silicon dioxide layer on the surface of the silicon carbide particles to obtain nano-silicon dioxide-coated silicon carbide particles;

[0058] The micro-oxidation treatment comprises the following steps: first, ultrasonically cleaning the silicon carbide particles with anhydrous ethanol for 25 minutes, then ultrasonically cleaning them with deionized water for 10 minutes, and finally drying them; spreading the cleaned silicon carbide particles on a crucible and placing them in a muffle furnace, heating the muffle furnace to 1100° C. and then keeping the temperature for 6 hours, replenishing air into the muffle furnace every hour, and finally cooling the crucible;

[0059] The purity of the silicon carbide particles is 99.9%, the particles are irregular in shape, and the particle size is 55-65 μm;

[0060] Step 2: Electroplating a nickel layer on the surface of the nano-silicon dioxide-coated silicon carbide particles to obtain slightly oxidized-electroplated nickel-coated silicon carbide particles;

[0061] The electroplating process is as follows: current density: 1A / dm2, temperature: 50°C, time: 1h, pH: 4, the temperature of the electroplating solution does not exceed 95°C, and the electroplating solution is stirred once every 5 minutes during the electroplating process to ensure the uniformity of the nickel layer on the surface of the silicon carbide particles. After the nickel electroplating is completed, the slightly oxidized-electroplated nickel-coated silicon carbide particles are separated and ultrasonically cleaned with deionized water for 30 minutes and dried.

[0062] The composition of the electroplating solution is: 450g / L nickel sulfamate, 40g / L boric acid, 20g / L nickel bromide, and 0.2g / L sodium lauryl sulfate;

[0063] Step 3: Using a ball mill, the slightly oxidized and nickel-plated silicon carbide particles and the aluminum powder are subjected to low-energy ball milling to uniformly distribute the slightly oxidized and nickel-plated silicon carbide particles in the aluminum powder to obtain a mixed powder;

[0064] The mass ratio of the aluminum powder to the slightly oxidized-electroplated nickel-coated silicon carbide particles and the nickel-coated silicon carbide particles is 2:3;

[0065] The aluminum powder has a purity of 99.9%, is spherical in shape, and has a particle size of 20-35 μm;

[0066] The ball mill is a planetary ball mill;

[0067] The low-energy ball milling process comprises: mixing aluminum powder and slightly oxidized-electroplated nickel-coated silicon carbide particles and then loading them into a ball mill; evacuating the ball mill and then introducing argon gas; performing dry milling with a ball-to-material ratio of 3:1 and a ball milling speed of 200 rpm for 4 hours, with the ball mill rotating in one direction and stopping for 10 minutes after every hour of milling to obtain a mixed powder;

[0068] Step 4: spraying the mixed powder obtained in step 3 onto the substrate by cold spraying to obtain a high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating;

[0069] The cold spraying process comprises: ultrasonically cleaning the spraying substrate with anhydrous ethanol for 30 minutes, taking it out and drying it, then sandblasting the surface to be sprayed, and cleaning the surface to be sprayed with an air gun after the treatment; loading the mixed powder obtained in step 3 into a powder feeder, fixing the substrate and cold spraying it with a spray gun, using argon as the powder feeding gas, the cold spraying trajectory is S-shaped, the spraying trajectory line spacing is 2 mm, the spraying beam is at 90 degrees to the surface to be sprayed, the gun speed is 200 mm / s, the vertical distance between the gun muzzle and the surface to be sprayed is 30 mm, the chamber pressure is 4 MPa, the chamber gas temperature is 600°C, and spraying is performed 5 times according to the required coating thickness;

[0070] The mass fraction of Ni in the aluminum-based composite coating reinforced with high-content micro-oxidation-electroplated nickel-coated silicon carbide particles obtained in this example was 2.46%. Microstructural observation of the aluminum-based composite coating reinforced with high-content micro-oxidation-electroplated nickel-coated silicon carbide particles obtained in this example showed an increase in coating thickness, indicating an increase in deposition amount and an increase in silicon carbide content in the coating, resulting in improved hardness, wear resistance, corrosion resistance, and oxidation resistance.

[0071] Figure 1 This is an SEM image of the nano-silicon dioxide-coated silicon carbide particles obtained in step 1 of Example 1; it shows that the surface of the silicon carbide particles obtained after the micro-oxidation treatment is mainly composed of O, Si, and C elements;

[0072] Figure 2 This is an XPS graph of the nano-silicon dioxide-coated silicon carbide particles obtained in step 1 of Example 1; it shows that the substance coated on the surface of the silicon carbide after the micro-oxidation treatment is mainly amorphous silicon dioxide; Figure 3 This is an SEM image of the slightly oxidized and nickel-electroplated silicon carbide particles obtained in step 2 of Example 1. Nickel particles of different sizes are observed attached to the surface of the slightly oxidized silicon carbide. Figure 4 This is the nickel element distribution diagram of the slightly oxidized-electroplated nickel-coated silicon carbide particles obtained in step 2 of Example 1. It is observed that the nickel element coated on the surface of the silicon carbide is evenly distributed; Figure 9This is a cross-sectional morphology of the aluminum-based composite coating with high content of slight oxidation and electroplated nickel coated with silicon carbide particles reinforced by cold spraying in step 4 of Example 1. It can be seen that the aluminum-based composite coating with high content of slight oxidation and electroplated nickel coated with silicon carbide particles reinforced by cold spraying technology was prepared.

[0073] Example 2:

[0074] The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating of this embodiment is carried out as follows:

[0075] Step 1: Under atmospheric conditions, the silicon carbide particles are subjected to a micro-oxidation treatment in a muffle furnace to in-situ grow a nano-amorphous silicon dioxide layer on the surface of the silicon carbide particles to obtain nano-silicon dioxide-coated silicon carbide particles;

[0076] The micro-oxidation treatment comprises the following steps: first, ultrasonically cleaning the silicon carbide particles with anhydrous ethanol for 20 minutes, then ultrasonically cleaning them with deionized water for 15 minutes, and finally drying them; spreading the cleaned silicon carbide particles on a crucible and placing them in a muffle furnace, heating the muffle furnace to 1100° C. and then keeping the temperature for 6 hours, replenishing air into the muffle furnace every hour, and finally cooling the crucible;

[0077] The purity of the silicon carbide particles is 99.9%, the particles are irregular in shape, and the particle size is 55-65 μm;

[0078] Step 2: Electroplating a nickel layer on the surface of the nano-silicon dioxide-coated silicon carbide particles to obtain slightly oxidized-electroplated nickel-coated silicon carbide particles;

[0079] The electroplating process is as follows: current density: 1.4A / dm2, temperature: 60°C, time: 1h, pH: 4.8, the temperature of the electroplating solution does not exceed 95°C, the electroplating solution is stirred once every 5 minutes during the electroplating process to ensure the uniformity of the nickel layer on the surface of the silicon carbide particles. After the nickel electroplating is completed, the slightly oxidized-electroplated nickel-coated silicon carbide particles are separated and ultrasonically cleaned with deionized water for 30 minutes and dried.

[0080] The composition of the electroplating solution is: 450g / L nickel sulfamate, 40g / L boric acid, 20g / L nickel bromide, and 0.2g / L sodium lauryl sulfate;

[0081] Step 3: Using a ball mill, the slightly oxidized and nickel-plated silicon carbide particles and the aluminum powder are subjected to low-energy ball milling to uniformly distribute the slightly oxidized and nickel-plated silicon carbide particles in the aluminum powder to obtain a mixed powder;

[0082] The mass ratio of the aluminum powder to the slightly oxidized-electroplated nickel-coated silicon carbide particles and the nickel-coated silicon carbide particles is 2:3;

[0083] The aluminum powder has a purity of 99.9%, is spherical in shape, and has a particle size of 20-35 μm;

[0084] The ball mill is a planetary ball mill;

[0085] The low-energy ball milling process comprises: mixing aluminum powder and micro-oxidized-electroplated nickel-coated silicon carbide particles and then loading them into a ball mill; evacuating the ball mill and then introducing argon gas; performing dry milling with a ball-to-material ratio of 3:1 and a ball milling speed of 150 rpm for 4 hours, with the ball mill rotating in one direction and stopping for 10 minutes after every hour of milling, to obtain a mixed powder;

[0086] Step 4: spraying the mixed powder obtained in step 3 onto the substrate by cold spraying to obtain a high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating;

[0087] The cold spraying process comprises: ultrasonically cleaning the spraying substrate with anhydrous ethanol for 10 minutes, taking it out and drying it, then sandblasting the surface to be sprayed, and cleaning the surface to be sprayed with an air gun after the treatment; loading the mixed powder obtained in step 3 into a powder feeder, fixing the substrate and cold spraying it with a spray gun, using argon as the powder feeding gas, the cold spraying trajectory is S-shaped, the spraying trajectory line spacing is 2mm, the spraying beam is at 90° to the surface to be sprayed, the gun speed is 200mm / s, the vertical distance between the gun muzzle and the surface to be sprayed is 30mm, the chamber pressure is 4MPa, the chamber gas temperature is 600°C, and the spraying is performed several times according to the required coating thickness;

[0088] The mass fraction of Ni in the high-content slightly oxidized-electroplated nickel-coated silicon carbide particle-reinforced aluminum-based composite coating obtained in this embodiment is 4.17%. The high-content slightly oxidized-electroplated nickel-coated silicon carbide particle-reinforced aluminum-based composite coating obtained in this embodiment not only increases the coating thickness, but also provides good interfacial bonding between the coating and the substrate, thereby increasing the surface hardness, wear resistance, corrosion resistance, and oxidation resistance of the magnesium alloy. It also prevents separation between the coating and the substrate due to external environmental influences. Furthermore, due to the improved interfacial bonding, the service life of the protective coating on the magnesium alloy surface can be extended. Figure 5 This is an SEM image of the slightly oxidized and nickel-electroplated silicon carbide particles obtained in step 2 of Example 2; nickel particles of different sizes are observed to be attached to the slightly oxidized silicon carbide surface; Figure 6 This is the nickel element distribution diagram of the slightly oxidized-electroplated nickel-coated silicon carbide particles obtained in step 2 of Example 2; it is observed that the nickel element coated on the silicon carbide surface is evenly distributed. Figure 10 This is a cross-sectional morphology of the high-content slightly oxidized-electroplated nickel-coated silicon carbide particle-reinforced aluminum-based composite coating obtained by cold spraying in step 4 of Example 2. This demonstrates that the slightly oxidized-electroplated nickel-coated silicon carbide particle-reinforced aluminum-based composite coating adheres well to the ZE41 magnesium alloy substrate, with no large pores or cracks observed.

[0089] Example 3

[0090] The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating of this embodiment is carried out as follows:

[0091] Step 1: Under atmospheric conditions, the silicon carbide particles are subjected to a micro-oxidation treatment in a muffle furnace to in-situ grow a nano-amorphous silicon dioxide layer on the surface of the silicon carbide particles to obtain nano-silicon dioxide-coated silicon carbide particles;

[0092] The micro-oxidation treatment comprises the following steps: first, ultrasonically cleaning the silicon carbide particles with anhydrous ethanol for 30 minutes, then ultrasonically cleaning them with deionized water for 15 minutes, and finally drying them; spreading the cleaned silicon carbide particles on a crucible and placing them in a muffle furnace, heating the muffle furnace to 1100° C. and then keeping the temperature for 6 hours, replenishing air into the muffle furnace every hour, and finally cooling the crucible;

[0093] The purity of the silicon carbide particles is 99.9%, the particles are irregular in shape, and the particle size is 55-65 μm;

[0094] Step 2: Electroplating a nickel layer on the surface of the nano-silicon dioxide-coated silicon carbide particles to obtain slightly oxidized-electroplated nickel-coated silicon carbide particles;

[0095] The electroplating process is as follows: current density: 1.4A / dm2, temperature: 60°C, time: 1h, pH: 3.6, the temperature of the electroplating solution does not exceed 95°C, the electroplating solution is stirred once every 5 minutes during the electroplating process to ensure the uniformity of the nickel layer on the surface of the silicon carbide particles. After the nickel electroplating is completed, the slightly oxidized-electroplated nickel-coated silicon carbide particles are separated and ultrasonically cleaned with deionized water for 30 minutes and dried.

[0096] The composition of the electroplating solution is: 450g / L nickel sulfamate, 40g / L boric acid, 20g / L nickel bromide, and 0.2g / L sodium lauryl sulfate;

[0097] Step 3: Using a ball mill, the slightly oxidized and nickel-plated silicon carbide particles and the aluminum powder are subjected to low-energy ball milling to uniformly distribute the slightly oxidized and nickel-plated silicon carbide particles in the aluminum powder to obtain a mixed powder;

[0098] The mass ratio of the aluminum powder to the slightly oxidized-electroplated nickel-coated silicon carbide particles and the nickel-coated silicon carbide particles is 2:3;

[0099] The aluminum powder has a purity of 99.9%, is spherical in shape, and has a particle size of 20-35 μm;

[0100] The ball mill is a planetary ball mill;

[0101] The low-energy ball milling process comprises: mixing aluminum powder and slightly oxidized-electroplated nickel-coated silicon carbide particles and then loading them into a ball mill; evacuating the ball mill and then introducing argon gas; performing dry milling with a ball-to-material ratio of 3:1 and a ball milling speed of 200 rpm for 2 hours, with the ball mill rotating in one direction and stopping for 10 minutes after every hour of milling to obtain a mixed powder;

[0102] Step 4: spraying the mixed powder obtained in step 3 onto the substrate by cold spraying to obtain a high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating;

[0103] The cold spraying process comprises: ultrasonically cleaning the spraying substrate with anhydrous ethanol for 30 minutes, taking it out and drying it, then sandblasting the surface to be sprayed, and then cleaning the surface to be sprayed with an air gun; loading the mixed powder obtained in step 3 into a powder feeder, fixing the substrate and cold spraying it with a spray gun, using argon as the powder feeding gas, the cold spraying trajectory is S-shaped, the spraying trajectory line spacing is 2 mm, the spraying beam is at 90 degrees to the surface to be sprayed, the gun speed is 150 mm / s, the vertical distance between the gun muzzle and the surface to be sprayed is 30 mm, the chamber pressure is 4 MPa, the chamber gas temperature is 550°C, and the spraying is repeated several times according to the required coating thickness;

[0104] The mass fraction of Ni in the high-content micro-oxidation-electroplated nickel-coated silicon carbide particles reinforced aluminum-based composite coating obtained in step 4 is 5.77%. The high-content micro-oxidation-electroplated nickel-coated silicon carbide particles reinforced aluminum-based composite coating obtained in this embodiment has an increased coating thickness, and the coating and the substrate interface are well bonded, avoiding the occurrence of separation between the coating and the substrate due to the influence of the external environment, thereby improving the service life of the magnesium alloy. In addition, due to the micro-oxidation-electroplated nickel-coated silicon carbide particles, the collision and fragmentation of silicon carbide are improved, and the generation of crack sources due to the large-scale fragmentation of silicon carbide is avoided, resulting in crack expansion and the entry of corrosive liquid. At the same time, the micro-oxidation-electroplated nickel-coated silicon carbide particles improve the wettability of the coated silicon carbide and aluminum particles, and the bonding between particles is improved, so that the density of the coating is improved. Therefore, the surface hardness, wear resistance, corrosion resistance and oxidation resistance of the magnesium alloy are all improved to varying degrees. Figure 7 This is an SEM image of the slightly oxidized and nickel-electroplated silicon carbide particles obtained in step 2 of Example 3; nickel particles of different sizes are observed attached to the surface of the slightly oxidized silicon carbide; Figure 8 This is a nickel element distribution diagram of the slightly oxidized-electroplated nickel-coated silicon carbide particles obtained in step 2 of Example 3; it shows that the nickel element coated on the silicon carbide surface is uniformly distributed; Figure 11This is a morphology image of the silicon carbide particles in the aluminum-based composite coating reinforced with high-content slightly oxidized and electroplated nickel-coated silicon carbide particles obtained by cold spraying in step 4 of Example 2. This shows that after the slightly oxidized and electroplated nickel coating, the silicon carbide particles undergo a transition from complete fragmentation due to collision to partial fragmentation at the particle edges.

Claims

1. A cold spraying method for a high-content micro-oxidation-electroplated nickel-coated silicon carbide particle-reinforced aluminum-based composite coating, characterized by: The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating is carried out in the following steps: Step 1: Under atmospheric conditions, the silicon carbide particles are subjected to a micro-oxidation treatment in a muffle furnace to in-situ grow a nano-amorphous silicon dioxide layer on the surface of the silicon carbide particles to obtain nano-silicon dioxide-coated silicon carbide particles; The micro-oxidation treatment comprises the following steps: first, ultrasonically cleaning the silicon carbide particles with anhydrous ethanol for 20-30 minutes, then ultrasonically cleaning them with deionized water for 10-15 minutes, and finally drying them; spreading the cleaned silicon carbide particles on a crucible and placing them in a muffle furnace, heating the muffle furnace to 1100-1200° C. and then keeping the temperature for 4-6 hours, replenishing air into the muffle furnace every 0.5-1 hour, and finally cooling the crucible; Step 2: Electroplating a nickel layer on the surface of the nano-silicon dioxide-coated silicon carbide particles to obtain slightly oxidized-electroplated nickel-coated silicon carbide particles; Step 3: Using a ball mill, the slightly oxidized and nickel-plated silicon carbide particles and the aluminum powder are subjected to low-energy ball milling to uniformly distribute the slightly oxidized and nickel-plated silicon carbide particles in the aluminum powder to obtain a mixed powder; The mass ratio of the aluminum powder to the slightly oxidized-electroplated nickel-coated silicon carbide particles is 1-2:3; The low-energy ball milling process comprises: mixing aluminum powder and slightly oxidized-electroplated nickel-coated silicon carbide particles and then loading the mixture into a ball mill; evacuating the ball mill and then introducing argon gas; performing dry milling with a ball-to-material ratio of 3-4:1 and a ball milling speed of 150-200 rpm for 2-4 hours, with the ball mill rotating in one direction and stopping for 5-10 minutes every 0.5-1 hour of milling to obtain a mixed powder; Step 4: spraying the mixed powder obtained in step 3 onto the substrate by cold spraying to obtain a high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating; The cold spraying process comprises: ultrasonically cleaning the spray substrate with anhydrous ethanol for 5-60 minutes, taking it out and drying it, then sandblasting the surface to be sprayed, and cleaning the surface to be sprayed with an air gun after the treatment; loading the mixed powder obtained in step 3 into a powder feeder, fixing the substrate and cold spraying it with a spray gun, using argon as the powder feeding gas, the cold spraying trajectory is S-shaped, the spraying trajectory line spacing is 2-3mm, the spraying beam is at 90 degrees to the surface to be sprayed, the gun speed is 150-200mm / s, the vertical distance between the gun muzzle and the surface to be sprayed is 30-35mm, the chamber pressure is 3.5-4MPa, the chamber gas temperature is 550-600℃, and the spraying is repeated several times according to the required coating thickness; The mass fraction of Ni in the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating obtained in step 4 is 2.46-5.77%.

2. The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating according to claim 1, characterized in that: The micro-oxidation treatment in step 1 includes the following steps: first, ultrasonically cleaning the silicon carbide particles with anhydrous ethanol for 20 minutes, then ultrasonically cleaning them with deionized water for 15 minutes, and finally drying them; spreading the cleaned silicon carbide particles on a crucible and placing them in a muffle furnace, heating the muffle furnace to 1100°C and keeping it warm for 6 hours, replenishing air into the muffle furnace every hour, and finally cooling them with the furnace.

3. The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating according to claim 1, characterized in that: The micro-oxidation treatment in step 1 includes the following steps: first, ultrasonically cleaning the silicon carbide particles with anhydrous ethanol for 25 minutes, then ultrasonically cleaning them with deionized water for 10 minutes, and finally drying them; spreading the cleaned silicon carbide particles on a crucible and placing them in a muffle furnace, heating the muffle furnace to 1100°C and keeping it warm for 6 hours, replenishing air into the muffle furnace every hour, and finally cooling them with the furnace.

4. The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating according to claim 1, characterized in that: The purity of the silicon carbide particles in step 1 is 99.9%, the particles are irregular in shape, and the particle size is 55-65 μm.

5. The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating according to claim 1, characterized in that: The electroplating process in step 2 is: current density: 1.0-1.4A / dm 2 , temperature: 50-60℃, time: 1h, pH: 3.6-4.8, the temperature of the plating solution does not exceed 95℃, the plating solution is stirred once every 5 minutes during the electroplating process to ensure the uniformity of the nickel layer on the surface of the silicon carbide particles. After the nickel electroplating is completed, the micro-oxidation-electroplated nickel-coated silicon carbide particles are separated and ultrasonically cleaned with deionized water for 20-30 minutes and dried.

6. The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating according to claim 5, characterized in that: The electroplating solution comprises 450 g / L nickel sulfamate, 40 g / L boric acid, 20 g / L nickel bromide, and 0.2 g / L sodium lauryl sulfate.

7. The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating according to claim 1, characterized in that: The purity of the aluminum powder in step 3 is 99.9%, the particles are spherical, and the particle size is 20-35 μm.

8. The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating according to claim 1, characterized in that: The ball mill in step 3 is a planetary ball mill.

9. The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating according to claim 1, characterized in that: The low-energy ball milling process described in step 3 is as follows: aluminum powder and micro-oxidation-electroplated nickel-coated silicon carbide particles are mixed and loaded into a ball mill; the ball mill is evacuated and then argon is introduced. The ball milling process is dry milling, the ball-to-material ratio is 3:1, the ball mill speed is 200 r / min, the ball milling is carried out for 4 hours, the ball mill rotates in one direction, and stops for 10 minutes after every 1 hour of ball milling to obtain a mixed powder.

10. The cold spraying method of the high-content micro-oxidation-electroplated nickel-coated silicon carbide particle reinforced aluminum-based composite coating according to claim 1, characterized in that: The cold spraying process described in step 4 is as follows: ultrasonically clean the spray substrate with anhydrous ethanol for 30 minutes, take it out and dry it, then sandblast the surface to be sprayed, and clean the surface to be sprayed with an air gun after treatment; the mixed powder obtained in step 3 is loaded into the powder feeder, and the substrate is fixed and cold sprayed using a spray gun. Argon is used as the powder feeding gas, the cold spray trajectory is S-shaped, the spray trajectory line spacing is 2mm, the spray beam is 90° to the surface to be sprayed, the gun speed is 200mm / s, the vertical distance between the muzzle and the surface to be sprayed is 30mm, the chamber pressure is 4MPa, the chamber gas temperature is 600℃, and spraying is performed 5 times according to the required coating thickness.

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