Ceramic-reinforced metal-based composite gradient wear-resistant coating for mine claw and preparation method of ceramic-reinforced metal-based composite gradient wear-resistant coating

Abstract

The invention discloses a ceramic reinforced metal matrix composite gradient wear-resistant coating for a mine claw, which is characterized in that the coating comprises a first transition coating, a second transition coating and a third functional coating from inside to outside from a matrix, wherein the first transition coating is composed of the following components in percentage by volume: 20% of TiC ceramic particles and 80% of 316L stainless steel powder; the second transition coating is composed of, by volume, 30% of TiC ceramic particles and 70% of 316L stainless steel powder. The third functional coating is composed of, by volume, 50% of TiC ceramic powder and 50% of 316L stainless steel powder. The coating has the advantages of high hardness, high wear resistance and the like, has strong bonding property with a mine claw base material, and can effectively protect the surface of the claw and prolong the service life of the claw. The optimal process parameters of each gradient coating are researched, and the cladding parameters are accurately regulated and controlled, so that the defects between layers are reduced, and the hardness and wear resistance of each gradient cladding coating are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal ceramic materials, and in particular relates to a ceramic-reinforced metal-based composite gradient wear-resistant coating for a mining hook and a preparation method thereof. Background Art

[0002] Mineral resources are a vital component of natural resources and a crucial material foundation for the development of human society. They are also a key factor in driving national economic development. Mining hooks are important mechanical equipment that play a crucial role in the transportation of mining resources. However, mining hooks often operate in harsh environments, such as those with large amounts of abrasive materials, subject to varying degrees of wear and failure. These conditions place extremely high demands on the equipment's wear resistance. Frequent contact with ore causes severe wear on the hooks, requiring frequent replacement or repair. The wear and failure of these metal parts not only results in significant resource waste but can also lead to safety incidents. Therefore, there is an urgent need to improve the wear resistance of materials, extend the service life of metal parts, and provide maximum safety for mining workers.

[0003] 40CrNiMo is a medium-carbon, low-alloy, high-strength steel with excellent comprehensive mechanical properties, including high strength, high toughness, and good hardenability. In addition, 40CrNiMo has high hardness and wear resistance, making it an ideal substrate material for heavy machinery components such as mining hooks. However, under certain extreme operating conditions, its surface wear resistance still needs to be further improved to meet higher usage requirements. Coatings developed and prepared based on traditional designs are no longer able to meet the performance requirements of new equipment components. Therefore, it is particularly important to adopt advanced surface modification technologies to improve the wear resistance and service life of components. Laser cladding technology, as an advanced surface modification technology, can form a coating with excellent performance on the surface of the substrate, thereby significantly improving the material's wear resistance, corrosion resistance and other properties. This technology uses a high-energy laser beam to rapidly melt a powder material of a specific composition and solidify it on the substrate surface, forming a coating with good metallurgical bonding. It has been widely used in the wear-resistant field.

[0004] In recent years, research on improving the performance of Fe-based coatings by laser cladding TiC ceramic particles has mainly focused on the basic theory of cladding, the process parameters for preparing the cladding layer, and the performance testing of single-pass cladding layers. Due to the large difference in physical and chemical properties between the Fe-based alloy and the TiC hard phase, stress concentration, cracks, and easy peeling of the coating are prone to occur. The use of laser cladding to prepare gradient coatings can effectively reduce the stress between the Fe-based alloy and TiC. Therefore, it is of great significance to study the preparation of TiC gradient coatings by laser cladding. Summary of the Invention

[0005] The present invention provides a ceramic-reinforced metal-based composite gradient wear-resistant coating for mining hooks and a method for its preparation. To overcome the shortcomings of prior art, such as internal unevenness, prone to cracking, and easy separation between the coating and the substrate, the present invention provides a ceramic-reinforced metal-based composite gradient wear-resistant coating for mining hooks and a method for its preparation. This coating offers advantages such as high hardness and wear resistance, while also exhibiting strong adhesion to the mining hook substrate, effectively protecting the hook surface and extending its service life.

[0006] The first object of the present invention is to provide a ceramic-reinforced metal-based composite gradient wear-resistant coating for a mining hook, which coating includes: a first transition coating, a second transition coating, and a third functional coating from the inside to the outside of the substrate; wherein: the first transition coating is composed of the following components in a volume ratio: 20% TiC ceramic particles and 80% 316L stainless steel powder; the second transition coating is composed of the following components in a volume ratio: 30% TiC ceramic particles and 70% 316L stainless steel powder; the third functional coating is composed of the following components in a volume ratio: 50% TiC ceramic powder and 50% 316L stainless steel powder.

[0007] Specifically, the thickness of the first transition coating is 0.5 to 1 mm, the thickness of the second transition coating is 0.5 to 1 mm, and the thickness of the third functional coating is 0.5 to 1 mm.

[0008] Specifically, the particle size of the TiC ceramic particles is 45 to 75 μm, and the particle size of the 316L stainless steel powder is 53 to 150 μm.

[0009] The second object of the present invention is to provide a method for preparing the ceramic-reinforced metal-based composite gradient wear-resistant coating for mining hooks, the method comprising the following steps:

[0010] S1 sequentially mix TiC ceramic particles and 316L stainless steel powder in a certain volume ratio and dry them to obtain a first mixed powder, a second mixed powder, and a third mixed powder;

[0011] S2 pre-treats the surface of the mining hook to obtain a pre-treated mining hook;

[0012] S3: clamping the pretreated mining hook on the laser cladding equipment, evenly spreading the first mixed powder on the pretreated mining hook, and forming a first transition coating on the surface of the pretreated mining hook through the first laser cladding process;

[0013] S4: evenly spreading the second mixed powder on the first transition coating layer, and forming a second transition coating layer on the surface of the first transition coating layer through a second laser cladding process;

[0014] S5 then evenly spreads the third mixed powder on the second transition coating, and forms a third functional coating on the surface of the second transition coating through a third laser cladding process, thereby obtaining a ceramic-reinforced metal-based composite gradient wear-resistant coating for mining hooks.

[0015] Specifically, the process parameters of the first laser cladding in step S3 are set as follows: spot diameter of 3 mm, defocus of 17 mm, laser power of 1400-2000 W, scanning rate of 15-17 mm / s, powder feeding speed of 1 r / min, overlap rate of 35-40%, and powder-carrying gas flow of argon of 5-40 L / min.

[0016] Specifically, the process parameters of the second laser cladding treatment in step S4 are set as follows: spot diameter is 3 mm, defocus is 17 mm, laser power is 2100-2400 W, scanning rate is 18-20 mm / s, powder feeding speed is 1.6 r / min, overlap rate is 41-45%, and powder-carrying gas flow is argon with a flow rate of 5-40 L / min.

[0017] Specifically, the process parameters of the third laser cladding treatment in step S5 are set as follows: spot diameter is 3 mm, defocus is 17 mm, laser power is 2500-2800 W, scanning rate is 18-20 mm / s, powder feeding speed is 1 r / min, overlap rate is 46-50%, and powder-carrying gas flow is argon with a flow rate of 5-40 L / min.

[0018] Specifically, the drying treatment in step S1 is to place the mixed powder in a vacuum drying oven and dry it at 100-120° C. for 60-90 minutes.

[0019] Specifically, step S2 includes washing and polishing the surface of the mining hook to obtain a pre-treated mining hook.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] (1) The present invention provides a gradient coating composed of TiC ceramic particles and 316L stainless steel in different volume ratios. The TiC ceramic particles can form particle reinforcement, refine the structure, and improve the hardness and wear resistance of the coating. The addition of 316L stainless steel can improve the toughness of the coating and extend the service life of the coating.

[0022] (2) The present invention adopts a gradient coating design, gradually increasing the TiC ceramic content layer by layer, so that different layers have a gradient transition, reducing internal defects and residual stress in the coating, thereby effectively suppressing cracks and pores in the coating, improving the interlayer bonding strength and the density of the intra-layer structure; and the coating has a strong bonding with the mining hook base material, which can effectively extend the service life of the hook;

[0023] (3) The laser cladding technology disclosed in the present invention can optimize the coating structure according to the requirements of different gradient coatings, and study the optimal process parameters of each gradient coating. By precisely controlling the cladding parameters, the defects between layers are reduced, the hardness and wear resistance of each gradient cladding layer are improved, and the coating performance is improved to meet the application requirements under complex working conditions.

[0024] (4) The present invention optimizes the process parameters of each layer in turn during the laser cladding process, and regulates the microstructure and mechanical properties of each coating layer by setting the process parameters within a specific range; regulates the temperature and solidification rate of the molten pool by optimizing the laser power range, and thus optimizes the microstructure and mechanical properties of each coating layer; affects the width, depth and dilution rate of the cladding layer and the uniformity of each coating layer by optimizing the scanning speed; optimizes the amount of powder sprayed onto the substrate per unit time by setting the powder feeding speed within a specific range, and thus regulates the thickness of the coating and the distribution of alloy elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 (a) is the metallographic structure of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention at 25X magnification;

[0026] Figure 1 (b) is the metallographic structure of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention at 50X magnification;

[0027] Figure 1 (c) is a metallographic structure diagram of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention at a magnification of 100X;

[0028] Figure 2 The XRD pattern of the third functional layer a in the composite gradient wear-resistant coating a prepared in Example 1 of the present invention;

[0029] Figure 3 Schematic diagram of the hardness of each layer of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention;

[0030] Figure 4 Schematic diagram of wear marks on the base a of the mining hook in Example 1 of the present invention;

[0031] Figure 5 Schematic diagram of the wear marks of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the contents of the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which the present invention pertains. The terms used in this specification are intended only to describe specific embodiments and are not intended to limit the present invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the listed items. It should be understood that, unless otherwise specified, the various raw materials in the present invention may be commercially available.

[0034] Example 1

[0035] S1: 20% TiC ceramic particles (particle size 45 μm) and 80% 316L stainless steel powder (particle size 53 μm) were mixed, placed in a vacuum drying oven, and dried at 100° C. for 60 min to obtain a first mixed powder a; 30% TiC ceramic particles and 70% 316L stainless steel powder were mixed, placed in a vacuum drying oven, and dried at 110° C. for 70 min to obtain a second mixed powder a; 50% TiC ceramic powder and 50% 316L stainless steel powder were mixed, placed in a vacuum drying oven, and dried at 120° C. for 90 min to obtain a third mixed powder a;

[0036] S2 washes the surface of the mining hook with ethanol to remove oil stains, and removes metal oxides by polishing to obtain a pretreated mining hook a;

[0037] S3: Mount the mining hook a on the laser cladding equipment, evenly spread the first mixed powder a on the pre-treated mining hook, adjust the laser spot and powder spot to be 0.5m above the surface of the mining hook a to be clad, and adjust the powder feeding nozzle so that the powder focus coincides with the laser focus; under the protection of argon gas with a powder-carrying airflow of 15L / min, control the key parameters of laser cladding as follows: spot diameter of 3mm, defocus of 17mm, laser power of 1400W, scanning rate of 17mm / s, powder feeding speed of 1r / min, and overlap rate of 35%; through the first laser cladding treatment, the first mixed powder a is clad on the surface of the mining hook a to form a first transition coating a;

[0038] S4 evenly spreads the second mixed powder a on the first transition coating a, adjusts the laser spot and powder spot to be located 0.5 m above the surface to be clad on the surface of the first transition coating a, and adjusts the powder feeding nozzle so that the powder focus coincides with the laser focus. Under an argon gas flow rate of 5 L / min, the key parameters of laser cladding are controlled as follows: the spot diameter is set to 3 mm, the defocus distance is set to 17 mm, the laser power is set to 2100 W, the scanning rate is set to 18 mm / s, the powder feeding speed is set to 1.6 r / min, and the overlap rate is set to 41%. The second transition coating a is formed on the surface of the first bottom layer a through the second laser cladding process.

[0039] S5 evenly spreads the third mixed powder a on the second transition coating, adjusts the laser spot and the powder spot to be located 0.5m above the surface of the second transition coating a to be clad, and adjusts the powder feeding nozzle so that the powder focus coincides with the laser focus; under an argon gas with a powder-carrying airflow of 40L / min, the parameters of the laser cladding are adjusted as follows: the spot diameter is set to 3mm, the defocus amount is 17mm, the laser power is 2800W, the scanning rate is 20mm / s, the powder feeding speed is 1.6r / min, and the overlap rate is 50%. Through the third laser cladding treatment, a third functional coating a is formed on the surface of the second transition coating a, and a ceramic reinforced metal-based composite gradient wear-resistant coating a for mining hooks is obtained.

[0040] Example 2

[0041] S1: 20% TiC ceramic particles (particle size of 60 μm) and 80% 316L stainless steel powder (particle size of 80 μm) were mixed, placed in a vacuum drying oven, and dried at 110° C. for 90 min to obtain a first mixed powder b; 30% TiC ceramic particles and 70% 316L stainless steel powder were mixed, placed in a vacuum drying oven, and dried at 100° C. for 70 min to obtain a second mixed powder b; 50% TiC ceramic powder and 50% 316L stainless steel powder were mixed, placed in a vacuum drying oven, and dried at 100° C. for 60 min to obtain a third mixed powder b;

[0042] S2 washes the surface of the mining hook with ethanol to remove oil stains, and removes metal oxides by polishing to obtain a pretreated mining hook b;

[0043] S3: Mount the mining hook b on the laser cladding equipment, evenly spread the first mixed powder b on the pre-treated mining hook, adjust the laser spot and powder spot to be 0.5m above the surface of the mining hook b to be clad, and adjust the powder feeding nozzle so that the powder focus coincides with the laser focus; under the protection of argon gas with a powder-carrying airflow of 5L / min, control the key parameters of laser cladding as follows: spot diameter of 3mm, defocus of 17mm, laser power of 1800W, scanning rate of 15mm / s, powder feeding speed of 1r / min, and overlap rate of 37%; through the first laser cladding treatment, the first mixed powder b is clad on the surface of the mining hook b to form a first transition coating b with a thickness of 0.5mm;

[0044] S4 evenly spreads the second mixed powder b on the first transition coating b, adjusts the laser spot and powder spot to be located 0.5m above the surface of the first transition coating b to be clad, and adjusts the powder feeding nozzle so that the powder focus coincides with the laser focus. Under an argon gas flow rate of 25L / min, the key parameters of laser cladding are controlled as follows: the spot diameter is set to 3mm, the defocus is set to 17mm, the laser power is set to 2300W, the scanning rate is set to 19mm / s, the powder feeding speed is set to 1.6r / min, and the overlap rate is set to 43%. A second transition coating b with a thickness of 0.8mm is formed on the surface of the first bottom layer b through the second laser cladding process.

[0045] S5 evenly spreads the third mixed powder b on the second transition coating, adjusts the laser spot and the powder spot to be located 0.5m above the surface of the second transition coating b to be clad, and adjusts the powder feeding nozzle so that the powder focus coincides with the laser focus; under an argon gas with a powder-carrying airflow of 30L / min, the parameters of the laser cladding are adjusted as follows: the spot diameter is set to 3mm, the defocus amount is 17mm, the laser power is 2700W, the scanning rate is 18mm / s, the powder feeding speed is 1.6r / min, and the overlap rate is 48%. Through the third laser cladding treatment, a third functional coating b is formed on the surface of the second transition coating b with a thickness of 1mm; a ceramic reinforced metal-based composite gradient wear-resistant coating b for mining hooks is obtained.

[0046] Example 3

[0047] S1: 20% TiC ceramic particles (particle size 75 μm) and 80% 316L stainless steel powder (particle size 150 μm) were mixed, placed in a vacuum drying oven, and dried at 110° C. for 90 min to obtain a first mixed powder c; 30% TiC ceramic particles and 70% 316L stainless steel powder were mixed, placed in a vacuum drying oven, and dried at 100° C. for 70 min to obtain a second mixed powder c; 50% TiC ceramic powder and 50% 316L stainless steel powder were mixed, placed in a vacuum drying oven, and dried at 100° C. for 60 min to obtain a third mixed powder c;

[0048] S2 washes the surface of the mining hook with ethanol to remove oil stains, and removes metal oxides by polishing to obtain a pretreated mining hook c;

[0049] S3: Mount the mining hook c on the laser cladding equipment, evenly spread the first mixed powder c on the pre-treated mining hook, adjust the laser spot and powder spot to be 0.5m above the surface of the mining hook c to be clad, and adjust the powder feeding nozzle so that the powder focus coincides with the laser focus; under the protection of argon gas with a powder-carrying airflow of 5L / min, control the key parameters of laser cladding as follows: spot diameter of 3mm, defocus of 17mm, laser power of 1800W, scanning rate of 15mm / s, powder feeding speed of 1r / min, and overlap rate of 37%; through the first laser cladding treatment, the first mixed powder c is clad on the surface of the mining hook c to form a first transition coating c with a thickness of 1mm;

[0050] S4 evenly spreads the second mixed powder c on the first transition coating c, adjusts the laser spot and powder spot to be located 0.5 m above the surface to be clad on the first transition coating c, and adjusts the powder feeding nozzle so that the powder focus coincides with the laser focus. Under an argon gas flow rate of 25 L / min, the key parameters of laser cladding are controlled as follows: the spot diameter is set to 3 mm, the defocus is set to 17 mm, the laser power is set to 2300 W, the scanning rate is set to 19 mm / s, the powder feeding speed is set to 1.6 r / min, and the overlap rate is set to 43%. A second transition coating c is formed on the surface of the first bottom layer c through the second laser cladding process, and its thickness is 1 mm.

[0051] S5 evenly spreads the third mixed powder c on the second transition coating, adjusts the laser spot and the powder spot to be located 0.5m above the surface of the second transition coating c to be clad, and adjusts the powder feeding nozzle so that the powder focus coincides with the laser focus; under an argon gas with a powder-carrying airflow of 30L / min, the laser cladding parameters are adjusted as follows: the spot diameter is set to 3mm, the defocus amount is 17mm, the laser power is 2700W, the scanning rate is 18mm / s, the powder feeding speed is 1.6r / min, and the overlap rate is 48%. Through the third laser cladding treatment, a third functional coating c is formed on the surface of the second transition coating c with a thickness of 1mm; a ceramic reinforced metal-based composite gradient wear-resistant coating c for mining hooks is obtained.

[0052] Example 4

[0053] S1: 20% Tid ceramic particles (particle size 71 μm) and 80% 316L stainless steel powder (particle size 103 μm) were mixed, placed in a vacuum drying oven, and dried at 120°C for 90 min to obtain a first mixed powder d; 30% Tid ceramic particles and 70% 316L stainless steel powder were mixed, placed in a vacuum drying oven, and dried at 120°C for 90 min to obtain a second mixed powder d; 50% Tid ceramic powder and 50% 316L stainless steel powder were mixed, placed in a vacuum drying oven, and dried at 120°C for 90 min to obtain a third mixed powder d;

[0054] S2 washes the surface of the mining hook with ethanol to remove oil stains, and removes metal oxides by polishing to obtain a pretreated mining hook d;

[0055] S3: The mining claw d is placed and clamped on the laser cladding equipment, and the first mixed powder d is evenly spread on the pre-treated mining claw. The laser spot and the powder spot are adjusted to be 0.5m above the surface to be clad on the surface of the mining claw d. The powder feeding nozzle is adjusted so that the powder focus coincides with the laser focus. Under the protection of argon gas with a powder-carrying airflow of 40L / min, the key parameters of laser cladding are regulated as follows: spot diameter of 3mm, defocus of 17mm, laser power of 2000W, scanning rate of 17mm / s, powder feeding speed of 1r / min, and overlap rate of 40%. The first mixed powder d is clad on the surface of the mining claw d through the first laser cladding process to form a first transition coating d with a thickness of 0.5mm.

[0056] S4 evenly spreads the second mixed powder d on the first transition coating d, adjusts the laser spot and powder spot to be located 0.5m above the surface to be clad on the first transition coating d, and adjusts the powder feeding nozzle so that the powder focus coincides with the laser focus. Under argon gas with a powder carrier flow rate of 40L / min, the key parameters of laser cladding are controlled as follows: the spot diameter is set to 3mm, the defocus distance is set to 17mm, the laser power is set to 2400W, the scanning rate is set to 20mm / s, the powder feeding speed is set to 1.6r / min, and the overlap rate is set to 45%. A second transition coating d with a thickness of 0.5mm is formed on the surface of the first bottom layer d through the second laser cladding process.

[0057] S5 evenly spreads the third mixed powder d on the second transition coating, adjusts the laser spot and powder spot to be located 0.5m above the surface of the second transition coating d to be clad, and adjusts the powder feeding nozzle so that the powder focus coincides with the laser focus; under argon gas with a powder-carrying airflow of 30L / min, the laser cladding parameters are adjusted as follows: the spot diameter is set to 3mm, the defocus amount is 17mm, the laser power is 2700W, the scanning rate is 18mm / s, the powder feeding speed is 1.6r / min, and the overlap rate is 48%. Through the third laser cladding treatment, a third functional coating d with a thickness of 0.5mm is formed on the surface of the second transition coating d; a ceramic-reinforced metal-based composite gradient wear-resistant coating d for mining hooks is obtained.

[0058] Performance Testing

[0059] The cross-sectional microstructures of the metal ceramic gradient coatings obtained in Examples 1 to 5 and Comparative Examples 1 to 2 were detected using an optical microscope, and the distribution characteristics of the TiC ceramic phase in the composite gradient wear-resistant coating a were analyzed by metallographic microscopy. Figure 1 (a) is the metallographic structure diagram of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention; Figure 1 It can be seen that the surface morphology of each coating layer is intact, the ceramic particles are evenly distributed inside the coating, and the internal morphology is complete; the surface between layers is smooth and continuous, and the interior is dense. Figure 1 (b) is the metallographic structure of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention at 50X magnification; Figure 1 (c) is the metallographic structure of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention at a magnification of 100X; Figure 1 As can be seen in (b), there are unmelted TiC particles dispersed in the cladding layer. As the TiC content increases from bottom to top, the number of unmelted particles also increases. Figure 1 As can be seen from (c), the cladding layer has a dense and uniform structure. The presence of unmelted particles can hinder grain growth, thereby refining the grains and playing a role in grain refinement, which can enhance the strength of the cladding layer.

[0060] In order to explore the phase composition of the composite gradient wear-resistant coating, XRD analysis was used to analyze the phase of the surface layer of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention. Figure 2 This is the XRD pattern of the third functional layer a in the composite gradient wear-resistant coating a prepared in Example 1 of the present invention. The diffraction peaks of this layer are primarily due to the Ni-Cr elements and TiC phase in the 316L stainless steel powder. The diffraction peaks of the coating are essentially consistent with those of the Ni-Cr-Fe austenite phase (PDF#35-1375) and the TiC stationary phase (PDF#65-0966).

[0061] The microhardness distribution was measured using an HVS-1000 Vickers hardness tester with a normal load of 300g and a loading time of 15s. Measurements were taken every 100μm from the third functional layer to the base material of the mining hook. To ensure data accuracy, the average of three measurements at the same depth was used as the microhardness value of the iron-based wear-resistant coating at that depth. Hardness tests were performed sequentially on the mining hook, first transition coating, second transition coating, and third functional coating in Example 1. Figure 3 Schematic diagram of the hardness of each layer of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention; as the TiC content increases, the coating hardness gradually increases, indicating that TiC can significantly improve the microhardness of the cladding layer. The average hardness of the mining hook substrate (green), the first transition coating (purple), the second transition coating (yellow) and the third functional coating (blue) are 211HV, 610HV, 630HV and 655HV, respectively. The average microhardness of the third functional coating is about 3.1 times the average microhardness of the mining hook substrate, which is much higher than that of the substrate. Compared with the mining hook substrate, the composite gradient coating a has a higher hardness and good wear resistance.

[0062] The wear resistance of the composite gradient wear-resistant coating was tested using an MRH-3W high-speed ring-block friction and wear tester according to GB / T12444-2006 "Metallic materials wear test methods - Test ring-test block sliding wear test". The test parameters were an applied load of 150N, a grinding time of 60min, and a speed of 200r / min. The test sample size was 19×12×12mm. 3 ,For the grinding pair, GCr15 steel with a surface Rockwell hardness of 62.5HRC was selected. The surface of the sample was machined before testing to ensure similar surface finish. Figure 4 Schematic diagram of wear marks on the base a of the mining hook in Example 1 of the present invention; Figure 5 Schematic diagram of the wear scar of the composite gradient wear-resistant coating a prepared in Example 1 of the present invention. Observation of the 2D and 3D morphologies and the wear scar schematics shows that the wear scar on the mining hook substrate is wide and deep, while the wear scar on the gradient coating a is narrow and shallow, with relatively mild surface wear. This demonstrates that the addition of TiC ceramic particles improves the wear resistance of the composite gradient coating. The coating utilizes a three-layer gradient design, significantly improving its wear resistance compared to the substrate and further enhancing its wear resistance compared to traditional single-layer coatings.

[0063] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A ceramic reinforced metal-based composite gradient wear-resistant coating for mining hooks, characterized in that: The coating comprises: a first transition coating, a second transition coating, and a third functional coating from the inside to the outside of the substrate; wherein: the first transition coating is composed of the following components in a volume ratio: 20% TiC ceramic particles and 80% 316L stainless steel powder; the second transition coating is composed of the following components in a volume ratio: 30% TiC ceramic particles and 70% 316L stainless steel powder; and the third functional coating is composed of the following components in a volume ratio: 50% TiC ceramic powder and 50% 316L stainless steel powder.

2. The coating according to claim 1, characterized in that The thickness of the first transition coating is 0.5 to 1 mm, the thickness of the second transition coating is 0.5 to 1 mm, and the thickness of the third functional coating is 0.5 to 1 mm.

3. The coating according to claim 1, characterized in that The particle size of the TiC ceramic particles is 45 to 75 μm, and the particle size of the 316L stainless steel powder is 53 to 150 μm.

4. A method for preparing a ceramic-reinforced metal-based composite gradient wear-resistant coating for a mining hook according to any one of claims 1 to 3, characterized in that: The steps include: S1 sequentially mix TiC ceramic particles and 316L stainless steel powder in a certain volume ratio and dry them to obtain a first mixed powder, a second mixed powder, and a third mixed powder; S2 pre-treats the surface of the mining hook to obtain a pre-treated mining hook; S3: clamping the pretreated mining hook on the laser cladding equipment, evenly spreading the first mixed powder on the pretreated mining hook, and forming a first transition coating on the surface of the pretreated mining hook through the first laser cladding process; S4: evenly spreading the second mixed powder on the first transition coating layer, and forming a second transition coating layer on the surface of the first transition coating layer through a second laser cladding process; S5 then evenly spreads the third mixed powder on the second transition coating, and forms a third functional coating on the surface of the second transition coating through a third laser cladding process, thereby obtaining a ceramic-reinforced metal-based composite gradient wear-resistant coating for mining hooks.

5. The method according to claim 4, characterized in that The process parameters of the first laser cladding in step S3 are set as follows: spot diameter of 3 mm, defocus of 17 mm, laser power of 1400-2000 W, scanning rate of 15-17 mm / s, powder feeding speed of 1 r / min, overlap rate of 35-40%, and powder-carrying air flow of argon of 5-40 L / min.

6. The method according to claim 4, characterized in that The process parameters of the second laser cladding treatment in step S4 are set as follows: spot diameter of 3 mm, defocus of 17 mm, laser power of 2100-2400 W, scanning rate of 18-20 mm / s, powder feeding speed of 1.6 r / min, overlap rate of 41-45%, and powder-carrying gas flow of argon with a flow rate of 5-40 L / min.

7. The method according to claim 4, characterized in that The process parameters of the third laser cladding treatment in step S5 are set as follows: spot diameter of 3 mm, defocus amount of 17 mm, laser power of 2500-2800 W, scanning rate of 18-20 mm / s, powder feeding speed of 1 r / min, overlap rate of 46-50%, and powder-carrying gas flow of argon with a flow rate of 5-40 L / min.

8. The method according to claim 4, characterized in that The drying process in step S1 is to place the mixed powder in a vacuum drying oven and dry it at 100-120° C. for 60-90 minutes.

9. The method according to claim 4, characterized in that Step S2 specifically includes washing and polishing the surface of the mining hook to obtain a pre-treated mining hook.

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