Cladding layer and cladding layer preparation process

Abstract

The invention provides a cladding layer and a preparation technology of the cladding layer, and belongs to the technical field of cladding layer preparation. The cladding layer comprises the following components in parts by weight: 50.0-65.0 parts of iron powder; 19-30 parts of a toughening agent; 3.0 to 5.0 parts of titanium carbide powder; 2.5 to 5 parts of a composite lubricant; 2.0 to 4.0 parts of alumina powder; 0.5 to 1.5 parts of yttrium powder; 4.0 to 6.0 parts of chromium powder; 1.0 to 2.0 parts of silicon powder; and 0.5 to 1.0 part of boron powder. Through a tough metal, hard phase and lubricating phase composite multi-component synergistic system, the comprehensive performance of a cladding layer is remarkably improved, and meanwhile, through combination of high-energy ball milling homogenization, base material activation pretreatment and dynamic laser cladding parameter regulation and control, the problems of uneven dispersion and thermal stress concentration of a traditional process are solved.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of cladding layer preparation, and particularly relates to a cladding layer and a cladding layer preparation process thereof. BACKGROUND

[0002] Wire additive manufacturing is an advanced manufacturing technology that forms a complex structure or strengthens the surface by depositing cladding layers layer by layer through the combination of continuous wire feeding and high-energy heat sources (such as laser, electric arc or plasma). The core of the technology is to use wire as raw material, and to realize directional accumulation and rapid prototyping of cladding layer preparation by precisely controlling the heat source and the wire feeding path. The technology is widely used in the fields of part repair, surface strengthening and customized manufacturing. The cladding layer is the key product of wire additive manufacturing, which refers to a functional coating formed on the surface of the base material by melting the wire material. In the process of wire additive manufacturing, the cladding layer not only protects the base material and prolongs the service life of the part, but also endows the surface with specific mechanical or physical properties. The performance of the cladding layer directly depends on the composition of the wire material and the process parameters.

[0003] Traditional wire additive manufacturing cladding layers usually use single metal or simple alloy systems (such as pure iron, nickel-based alloy or cobalt-based alloy). The process relies on conventional arc or laser welding technology to form the coating through a simple melting-solidification process. Such process has fixed parameters, poor matching of powder or wire feeding rate and heat source, and lacks fine regulation of the dynamic behavior of the molten pool. In addition, the traditional cladding layer has a single composition, which is difficult to meet the multiple performance requirements of toughening, low friction and wear resistance. Due to the lack of component synergistic optimization and dynamic parameter adjustment, the coating is prone to internal pores, cracks and grain coarsening, which reduces the bonding strength and service life. In addition, the imbalance of the ratio of traditional lubricating phase and hard phase leads to high friction coefficient and large wear rate, which limits its application in harsh working conditions. SUMMARY

[0004] The present disclosure aims to at least solve one of the technical problems existing in the prior art, and provides a cladding layer and a preparation process of the cladding layer.

[0005] In one aspect of the present disclosure, a cladding layer is provided, which comprises: 50.0-65.0 parts of iron powder; 19-30 parts of a toughening agent; 3.0-5.0 parts of titanium carbide powder; 2.5-5 parts of a composite lubricant; 2.0-4.0 parts of aluminum oxide powder; 0.5-1.5 parts of yttrium powder; 4.0-6.0 parts of chromium powder; 1.0-2.0 parts of silicon powder; 0.5-1.0 parts of boron powder. Optionally, the toughness agent comprises vanadium carbide powder, cobalt powder and molybdenum powder.

[0006] Optionally, the content ratio of the vanadium carbide powder and the cobalt powder and the molybdenum powder is (6.0-10.0):(5.0-8.0):(8.0-12.0).

[0007] Optionally, the composite lubricant comprises boron nitride powder and calcium fluoride powder.

[0008] Optionally, the content ratio of the boron nitride powder and the calcium fluoride powder is (1.5-3.0):(1.0-2.0).

[0009] Optionally, the particle size of the iron powder is 50-150 µm; the particle size of the titanium carbide powder is 1-10 µm; the particle size of the aluminum oxide powder is 5-30 µm; the particle size of the yttrium powder is 0.5-5 µm; the particle size of the chromium powder is 20-100 µm.

[0010] In another aspect of the present disclosure, a preparation process of the cladding layer as described above is provided, and the preparation process comprises: iron powder 50.0-65.0 parts, toughness agent 19-30 parts, titanium carbide powder 3.0-5.0 parts, composite lubricant 2.5-4.0 parts, yttrium powder 0.5-1.5 parts, chromium powder 4.0-6.0 parts, silicon powder 1.0-2.0 parts, and boron powder 0.5-1.0 parts are mixed in a certain proportion, ball-milled and sieved to obtain a homogenized mixed powder; the substrate is sandblasted to form an activated surface with a roughness Ra of 3.2-6.3 µm, and the substrate is sequentially cleaned, dried by high-pressure nitrogen and preheated; the preheated mixed powder is loaded into a powder feeder of a laser cladding device, and multi-pass overlapping cladding is performed on the surface of the substrate to obtain a cladding layer on the surface of the substrate; the cladding layer is annealed in a vacuum annealing furnace.

[0011] Optionally, the ball-milling time is 4-6 hours; the sieving process uses a screen with a mesh size ≤50 µm.

[0012] Optionally, the cleaning time of the substrate is 10-15 minutes; the preheating temperature of the substrate is 200-300 ℃, and the holding time is 30-60 minutes.

[0013] Optionally, in the laser cladding stage, the powder feeding rate is 30-40 g / min, the laser power is 2500-3500 W, the laser focal point position is set to 1-2 mm above the substrate surface, the molten pool temperature is 1800-2200 DEG C, and after each layer of cladding, rapid solidification is carried out by using argon gas cooling at a wind speed of 3-5 m / s, and the thickness of the cladding layer is 1.0-3.0 mm.

[0014] The present disclosure provides a cladding layer and a preparation process thereof. The cladding layer comprises: 50.0-65.0 parts of iron powder; 19-30 parts of a toughness agent; 3.0-5.0 parts of titanium carbide powder; 2.5-5 parts of a composite lubricant; 2.0-4.0 parts of aluminum oxide powder; 0.5-1.5 parts of yttrium powder; 4.0-6.0 parts of chromium powder; 1.0-2.0 parts of silicon powder; and 0.5-1.0 parts of boron powder. Through the composite multi-component synergistic system of the toughness metal, the hard phase and the lubricating phase, the comprehensive performance of the cladding layer is significantly improved. At the same time, by combining high-energy ball milling homogenization, substrate activation pretreatment and dynamic laser cladding parameter regulation, the problems of uneven dispersion and thermal stress concentration in the traditional process are solved. The cladding layer prepared by the present disclosure has high strength and toughness, low friction coefficient, excellent impact resistance and wear resistance. At the same time, the surface quality is optimized through vacuum annealing and precision grinding. The technical bottleneck of single performance and easy failure of traditional coatings is broken, and the present disclosure is suitable for high-load and high-wear industrial scenes. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The flowchart of the preparation process of the cladding layer of the specific embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0016] In order for those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and are part of the embodiments of the present disclosure, but not all embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present disclosure.

[0017] In one aspect of the present disclosure, a cladding layer is provided, which comprises: 50.0-65.0 parts of iron powder; 19-30 parts of a toughness agent; 3.0-5.0 parts of titanium carbide powder; 2.5-5 parts of a composite lubricant; 2.0-4.0 parts of aluminum oxide powder; 0.5-1.5 parts of yttrium powder; 4.0-6.0 parts of chromium powder; 1.0-2.0 parts of silicon powder; and 0.5-1.0 parts of boron powder. In the embodiment, the comprehensive performance of the cladding layer is significantly improved by the multi-component synergistic system of the tough metal, the hard phase and the lubricating phase. Meanwhile, the problems of uneven dispersion and thermal stress concentration in the traditional process are solved by combining high-energy ball milling homogenization, substrate activation pretreatment and dynamic laser cladding parameter regulation. The cladding layer prepared by the application has high strength and toughness, low friction coefficient, excellent impact resistance and wear resistance. Meanwhile, the surface quality is optimized by vacuum annealing and precision grinding. The technical bottleneck of single performance and easy failure of the traditional coating is broken. The application is suitable for high-load and high-wear industrial scenes.

[0018] In some preferred embodiments, the toughening agent includes vanadium carbide powder, cobalt powder and molybdenum powder, and each component is used to balance wear resistance and impact resistance. Among them, vanadium carbide provides a wear resistance skeleton, cobalt-molybdenum alloy provides a toughness matrix, and the three form a "hard point dispersion reinforced composite structure", achieving a three-dimensional balance of "wear resistance-toughness-strength". Especially, the high-temperature synergistic strengthening of vanadium carbide and molybdenum powder forms a composite carbide, effectively improving the high-temperature strength.

[0019] As a further preferred scheme, the content ratio of the vanadium carbide powder and the cobalt powder and the molybdenum powder is (6.0~10.0):(5.0~8.0):(8.0~12.0).

[0020] In other preferred embodiments, the composite lubricant includes boron nitride powder and calcium fluoride powder. Calcium fluoride is a layered solid lubricant that can form a layered film that is easy to shear and slip at high temperatures, significantly reducing the friction coefficient. Especially, the synergistic effect of boron nitride can maintain stable lubrication performance in a wide temperature range. That is, the composite lubricant can reduce the friction coefficient and reduce the stress concentration of the hard phase caused by friction impact; at the same time, the hard phase supports the lubricating film to avoid excessive extrusion and loss of the lubricating phase under heavy load, and the two form a "friction reduction-wear resistance synergistic protective layer". At the same time, the composite lubricant also matches the matrix of the toughening agent to improve the density of the coating.

[0021] As a further preferred scheme, the content ratio of the boron nitride powder and the calcium fluoride powder is (1.5~3.0):(1.0~2.0).

[0022] In other preferred embodiments, the iron powder is prepared by high-temperature reduction reaction of iron ore in a hydrogen reduction atmosphere, and the particle size of the iron powder is 50~150µm.

[0023] In other preferred embodiments, the titanium carbide powder is prepared by high-temperature electric arc smelting of titanium powder and carbon black in an argon protection environment, and the particle size of the titanium carbide powder is 1~10µm.

[0024] In other preferred embodiments, the alumina powder is prepared by calcination decomposition of bauxite at 1200~1500℃, and the particle size of the alumina powder is 5~30µm.

[0025] In some other preferred embodiments, the yttrium powder is prepared by calcothermal reduction of yttrium oxide in a vacuum environment, and the particle size of the yttrium powder is 0.5~5µm.

[0026] In some other preferred embodiments, the chromium powder is prepared by reducing chromium trioxide in a hydrogen atmosphere at high temperature, and the particle size of the chromium powder is 20~100µm.

[0027] like Figure 1 As shown, in another aspect of this disclosure, a preparation process S100 for the cladding layer described above is proposed, specifically including the following steps S110 to S140: S110, 50.0~65.0 parts of iron powder, 19~30 parts of toughening agent, 3.0~5.0 parts of titanium carbide powder, 2.5~4.0 parts of composite lubricant, 0.5~1.5 parts of yttrium powder, 4.0~6.0 parts of chromium powder, 1.0~2.0 parts of silicon powder, and 0.5~1.0 parts of boron powder are added to a ball mill jar in proportion. The ball milling time is set to 4~6 hours. The components are evenly dispersed by mechanical force and collision to avoid the agglomeration of hard phase. The homogenized mixed powder is obtained by passing it through a sieve with a mesh size ≤50µm and stored in a dry inert atmosphere container for later use. S120. The substrate is sandblasted to remove the surface oxide layer and form an activated surface with a roughness of Ra3.2~6.3µm. The substrate is then immersed in an ultrasonic cleaning tank for 10~15 minutes to remove grease and residual abrasive. The surface is dried with high-pressure nitrogen and then transferred to a preheating furnace to be preheated to 200~300℃ and held for 30~60 minutes to reduce thermal stress during the cladding process.

[0028] S130, Laser Cladding Deposition: The mixed powder is loaded into the powder feeder, and the powder feeding rate is adjusted to match the laser power. When the iron powder particle size is 50~150µm, the powder feeding rate is 30~40g / min, and the laser power is 2500~3500W. Multiple overlapping cladding layers are applied to the substrate surface. The laser focus position is set 1~2mm above the substrate surface, and the molten pool temperature is 1800~2200℃. The temperature is monitored in real time by an infrared thermometer. After each cladding layer, argon gas is used for rapid solidification at a wind speed of 3~5m / s to suppress grain coarsening. The cumulative deposition layer thickness is 1.0~3.0mm.

[0029] It should be noted that in the laser cladding deposition process, a layer of cladding powder is first laid on the surface of the substrate by mixing powder. After laser cladding, a cladding layer is formed. This process is repeated to form multiple deposited cladding layers on the surface of the substrate, accumulating the deposited cladding layers.

[0030] S140. The cladding layer is subjected to stress-relief annealing in a vacuum annealing furnace to eliminate residual stress and improve strength and toughness, and performance testing is performed.

[0031] In step S140, the temperature of the annealing treatment is 650-750°C for 1-2 hours. At this annealing temperature, the cladding layer components (e.g., yttrium powder and toughness agent) can effectively refine the grains and release stress, avoiding the crack problem of the traditional process.

[0032] It should be noted that during the performance test of the cladding layer, mainly including the strength and toughness performance test, the friction performance test, the impact resistance performance test and the wear performance test.

[0033] The preparation process of the cladding layer will be further described below with specific examples: Example 1 In this example 1, the material components are as follows, please refer to Table 1: Iron powder: 57.5 parts; Toughness agent: vanadium carbide powder 8.0 parts, cobalt powder 6.5 parts, molybdenum powder 10.0 parts; Composite lubricant: boron nitride powder 2.25 parts, calcium fluoride powder 1.5 parts; Alumina powder: 3.0 parts, yttrium powder: 1.0 part, chromium powder: 5.0 parts, silicon powder: 1.5 parts, boron powder: 0.75 parts.

[0034] The cladding layer is prepared according to the process given above, wherein the process parameters are: pre-mixed homogenization in a high-energy ball mill, rotation speed 400 rpm, ball-to-material ratio 10:1, argon protection, ball milling time 5 hours, sieving 50 µm; When the substrate is pretreated, the sandblasting pressure is 0.7 MPa, the ultrasonic cleaning is 12 minutes, and the preheating is 250°C for 45 minutes; When laser cladding, the powder feeding rate is 35 g / min, the laser power is 3000 W, the scanning speed is 10 mm / s, the molten pool temperature is 2000°C, and the argon cooling air speed is 4 m / s; When post-processing, vacuum annealing at 700°C for 1.5 hours, grinding roughness Ra 0.6 µm.

[0035] Example 2 In this example, the vanadium carbide powder is 6.0 parts, which is at the lower limit of the toughness agent proportion range, and the other process parameters and cladding layer powder components are the same as example 1, please refer to Table 1.

[0036] Example 3 In this example, the boron nitride powder is 3.0 parts, which is at the upper limit of the composite lubricant proportion range, and the other process parameters and cladding layer powder components are the same as example 1, please refer to Table 1.

[0037] Example 4 In this embodiment, the molybdenum powder is 12.0 parts, which is at the upper limit of the range of the proportion of the toughening agent, and other process parameters and the composition of the cladding layer powder are the same as those in Example 1. Please refer to Table 1.

[0038] Example 5 In this embodiment, the yttrium powder is 0.5 parts, which is at the lower limit of the range of the proportion of the yttrium powder, and other process parameters and the composition of the cladding layer powder are the same as those in Example 1. Please refer to Table 1.

[0039] Example 6 In this embodiment, the yttrium powder is 1.5 parts at the upper limit, and other process parameters and the composition of the cladding layer powder are the same as those in Example 1. Please refer to Table 1.

[0040] Example 7 In this embodiment, the vanadium carbide powder is 10.0 parts at the upper limit, and other process parameters and the composition of the cladding layer powder are the same as those in Example 1. Please refer to Table 1.

[0041] Example 8 In this embodiment, the boron nitride powder is 1.5 parts at the lower limit, and other process parameters and the composition of the cladding layer powder are the same as those in Example 1. Please refer to Table 1.

[0042] Example 9 In this embodiment, the molybdenum powder is 8.0 parts at the lower limit, and other process parameters and the composition of the cladding layer powder are the same as those in Example 1. Please refer to Table 1.

[0043] The cladding layers prepared in the above embodiments are tested for strength and toughness, friction coefficient, impact resistance, and wear rate, and the steps are as follows: a. Strength and toughness test: standard tensile specimens are cut from the cladding layer, and three-point bending test is performed on a universal material testing machine based on ASTM E8 and ASTM E399 standards; b. Friction coefficient test: a 6-10 mm diameter cladding layer specimen (flat surface) is taken with a standard steel ball / disk, and a ball-disk friction and wear testing machine is used to perform the experiment according to ASTM G99 standard; c. Impact resistance test: standard notched impact specimens (V-shaped notch, size 10x10x55 mm) are processed, and Charpy impact test is performed on a pendulum impact testing machine according to ASTM E23 standard; d. Wear rate test: the cladding layer specimen is tested with sandpaper / hard alloy disk on a pin-disk wear testing machine according to ASTM G65 standard. The test results are shown in Table 2.

[0044] Table 1 Composition parameters of the cladding layer in Examples 1-9

[0045] Table 2 Product performance parameters of the preparation process of Example 1-Example 9

[0046] Comparative Example 1 In this comparative example, the vanadium carbide powder is 4.0 parts, which is lower than the lower limit of the range of the toughness agent ratio, and other process parameters and cladding layer powder components are the same as those in Example 1, please refer to Table 3.

[0047] Comparative Example 2 In this comparative example, the boron nitride powder is 4.0 parts, which is higher than the upper limit of the range of the composite lubricant ratio, and other process parameters and cladding layer powder components are the same as those in Example 1, please refer to Table 3.

[0048] Comparative Example 3 In this comparative example, the molybdenum powder is 15.0 parts, which is higher than the upper limit of the range of the toughness agent ratio, and other process parameters and cladding layer powder components are the same as those in Example 1, please refer to Table 3.

[0049] Comparative Example 4 In this comparative example, the yttrium powder is 0.3 parts, which is lower than the lower limit of the range of the yttrium powder ratio, and other process parameters and cladding layer powder components are the same as those in Example 1, please refer to Table 3.

[0050] Comparative Example 5 In this comparative example, the boron powder is 1.5 parts, which is higher than the upper limit of the range of the boron powder ratio, and other process parameters and cladding layer powder components are the same as those in Example 1, please refer to Table 3.

[0051] The cladding layers prepared in the above comparative examples are tested for strength and toughness, friction coefficient, impact resistance and wear rate performance, and the steps are as follows: a. Strength and toughness test: standard tensile specimens are cut from the cladding layer and three-point bending test is performed by a universal material testing machine based on ASTM E8 and ASTM E399 standards; b. Friction coefficient test: a 6-10 mm diameter cladding layer specimen (flat surface) is taken with a standard steel ball / disk, and a ball-disk friction and wear testing machine is used to test according to ASTM G99 standard; c. Impact resistance test: standard notched impact specimens (V-shaped notch, size 10x10x55 mm) are processed, and Charpy impact test is performed by a pendulum impact testing machine according to ASTM E23 standard; d. Wear rate test: the cladding layer specimen is tested with sandpaper / hard alloy disk by a pin-disk wear testing machine according to ASTM G65 standard. The test results are shown in Table 4.

[0052] Table 3 Component parameters of the cladding layer in Comparative Example 1 to Comparative Example 5

[0053] Table 4 Product performance parameters of the preparation process of Comparative Examples 1-5

[0054] According to the results of Tables 1-4 above, the insufficient vanadium carbide of Comparative Example 1 of the present application caused the strength and toughness of the cladding layer to drop to 950 MPa, and the wear rate was as high as 8.2; the insufficient yttrium powder of Comparative Example 4 caused serious grain coarsening, and the impact toughness was only 18 J / cm 2 ; the excessive boron of Comparative Example 5 caused grain boundary embrittlement, and the wear rate exceeding the interval would cause imbalance of the phase structure or performance degradation, verifying the necessity of the powder ratio range in the present application. Furthermore, when the vanadium carbide content of Example 2 was at the lower limit, the hardness phase was insufficient, resulting in reduced wear resistance and impact toughness; the friction coefficient of Example 3 was the lowest, but the excess lubricating phase caused a slight decrease in strength and toughness; when the yttrium powder content of Example 5 was at the lower limit, grain coarsening occurred, and the wear rate increased significantly; when the yttrium powder content of Example 6 reached the upper limit, the grains were refined, but the ratio needed to be controlled to avoid brittleness; when the vanadium carbide content of Example 7 reached the upper limit, the wear resistance was improved, but the toughness needed to be balanced; and when the boron nitride content of Example 8 was at the lower limit and the molybdenum powder content of Example 9 was at the lower limit, the performance of the cladding layer was degraded. Therefore, the comprehensive performance of Example 1 was the best, with balanced strength and toughness (1250 MPa), low friction (0.18), high impact toughness (45 J / cm 2 ), and low wear rate (2.1 x 10 -8 ).

[0055] In summary, through multiple example and comparative example tests, the best embodiment of the present disclosure is as follows: the toughness agent is 8.0 parts of vanadium carbide, 6.5 parts of cobalt, and 10.0 parts of molybdenum, which optimizes the ratio of hard phase and tough phase; secondly, the composite lubricant is 2.25 parts of boron nitride and 1.5 parts of calcium fluoride, which cooperatively reduces friction; in addition, 1.0 part of yttrium powder refines the grains, and the above components and ratios can improve the strengthening and toughening effect.

[0056] The present disclosure proposes a cladding layer and a cladding layer preparation process, which has the following beneficial effects compared with the prior art: the present application significantly improves the comprehensive performance of the cladding layer through a multi-component synergistic system of tough metal, hard phase, and lubricating phase, and solves the problems of uneven distribution and thermal stress concentration in traditional processes by combining high-energy ball milling homogenization, substrate activation pretreatment, and dynamic laser cladding parameter regulation. The cladding layer prepared by the present application has high strength and toughness, low friction coefficient, excellent impact resistance, and wear resistance, and the surface quality is optimized through vacuum annealing and precision grinding, breaking through the technical bottleneck of single performance and easy failure of traditional coatings, and is suitable for high-load and high-wear industrial scenarios.

[0057] It is understood that the above embodiments are only exemplary for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A cladding layer characterized in that, The cladding layer includes: 50.0~65.0 parts of iron powder; 19-30 parts of toughening agent; 3.0~5.0 parts of titanium carbide powder; 2.5 to 5 parts of compound lubricant; 2.0~4.0 parts of alumina powder; 0.5 to 1.5 parts of yttrium powder; 4.0~6.0 parts of chromium powder; 1.0~2.0 parts of silicon powder; 0.5 to 1.0 parts of boron powder.

2. The cladding layer according to claim 1, characterized in that The toughening agent includes vanadium carbide powder, cobalt powder, and molybdenum powder.

3. The cladding layer according to claim 2, characterized in that The content ratio of the vanadium carbide powder, the cobalt powder, and the molybdenum powder is (6.0~10.0):(5.0~8.0):(8.0~12.0).

4. The cladding layer of claim 1, wherein, The composite lubricant includes boron nitride powder and calcium fluoride powder.

5. The cladding layer of claim 4, wherein, The content ratio of boron nitride powder and calcium fluoride powder is (1.5~3.0):(1.0~2.0).

6. The cladding layer of claim 1, wherein, The iron powder has a particle size of 50~150µm; The particle size of the titanium carbide powder is 1~10µm; The alumina powder has a particle size of 5~30µm; The particle size of the yttrium powder is 0.5~5µm; The particle size of the chromium powder is 20~100µm.

7. A process for preparing a cladding layer as described in any one of claims 1-6, characterized in that, The preparation process includes: 50.0~65.0 parts of iron powder, 19~30 parts of toughening agent, 3.0~5.0 parts of titanium carbide powder, 2.5~4.0 parts of composite lubricant, 0.5~1.5 parts of yttrium powder, 4.0~6.0 parts of chromium powder, 1.0~2.0 parts of silicon powder, and 0.5~1.0 parts of boron powder are mixed in a certain proportion and then ball-milled and sieved to obtain a homogenized mixed powder. The substrate is sandblasted to form an activated surface with a roughness Ra of 3.2~6.3µm, and the substrate is then cleaned, dried with high-pressure nitrogen, and preheated. The preheated mixed powder is loaded into the powder feeder of the laser cladding equipment and multiple overlapping claddings are performed on the substrate surface to obtain a cladding layer on the substrate surface. The cladding layer is annealed in a vacuum annealing furnace.

8. The preparation process according to claim 7, characterized in that, The ball milling process takes 4-6 hours; The sieving process uses a screen with a mesh size ≤ 50µm.

9. The preparation process according to claim 7, characterized in that, The cleaning time for the substrate is 10-15 minutes; The temperature for preheating the substrate is 200~300℃, and the holding time is 30~60 minutes.

10. The preparation process according to claim 7, characterized in that, During the laser cladding stage, the powder feeding rate is 30~40g / min, the laser power is 2500~3500W, the laser focus position is set to 1~2mm above the substrate surface, the molten pool temperature is 1800~2200℃, and each layer is rapidly solidified by argon air cooling at a wind speed of 3~5m / s after cladding. The thickness of the cladding layer is 1.0~3.0mm.

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