Preparation method of high-entropy alloy powder and surface bionic ploughshare self-grinding blade coating

Abstract

The application relates to a preparation method of a high-entropy alloy powder and a surface biomimetic ploughshare self-sharpening coating, which comprises the following steps: pretreating the surface of a base material 65Mn steel; preparing Al2FeCoNiCrW 0.5 The size of the high-entropy alloy powder is 200-300 meshes; a surface biomimetic coating is prepared by adopting a laser cladding method, high-energy-density laser beams are used to melt the high-entropy alloy powder and the surface material of the contacted base material together, a metallurgical reaction is caused, and finally, the cladding layer with excellent performance is formed by rapid cooling and solidification; wherein the back of the ploughshare is cladded to obtain a ribbed biomimetic anti-friction wear-resistant structure, and the front of the ploughshare is cladded to obtain a convex biomimetic anti-friction wear-resistant structure. The high-entropy alloy coating is prepared on both sides of the ploughshare blade by using the laser cladding technology, so that two biomimetic surfaces with different wear resistances are formed, the blade becomes sharper with wear, the self-sharpening effect is achieved, and the wear resistance and the anti-friction performance of the surface of the ploughshare are improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery processing technology, specifically to a method for preparing a biomimetic plowshare self-sharpening blade coating based on high-entropy alloy powder. Background Technology

[0002] In modern agricultural production, agricultural machinery is widely used, and the development of agricultural mechanization has brought about tremendous changes to agricultural production. Therefore, the stability and reliability of mechanized agricultural operations are particularly important. Many factors affect the stability and reliability of agricultural machinery, with the most significant issue being the severe wear and tear on agricultural machinery components during use. Surveys show that approximately 50% of agricultural machinery malfunctions each year are caused by component failures, and wear and breakage of soil-contacting components account for about 80% of these failures. Therefore, improving the wear resistance of soil-contacting components plays a crucial role in the development of agricultural mechanization.

[0003] The wear mechanism of agricultural machinery components in soil is primarily abrasive wear. For example, the blades of plowshares, harrows, subsoilers, furrow openers, and rotary tillers, which break up soil, experience intense wear primarily from hard abrasive particles such as stones and sand when the blades cut into the soil and break up clods. Existing wear-resistant treatment methods for these components address this wear mechanism by creating an additive manufacturing process. This involves forming a wear-resistant layer on the surface of the machinery, such as through welding, cladding, or thermal spraying. However, this method has several drawbacks: the wear-resistant layer is difficult to bond to the surface, leading to breakage; the process is also complex and costly. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a biomimetic plowshare self-sharpening blade coating based on high-entropy alloy powder. This method is used to solve the problem of severe wear on soil-contacting parts of agricultural machinery during use.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: This method for preparing a biomimetic plowshare self-sharpening coating based on high-entropy alloy powder includes the following steps:

[0006] Step 1: Pre-treatment of the 65Mn steel substrate surface;

[0007] Step 2: Preparation of Al2FeCoNiCrW 0.5 High-entropy alloy powder, wherein the raw material composition of the high-entropy alloy powder, expressed in molar ratio, is as follows:

[0008] Al:Fe:Co:Ni:Cr:W=2:1:1:1:1:0.5; the size of the high-entropy alloy powder is 200-300 mesh;

[0009] Step 3: Prepare the surface biomimetic coating:

[0010] The Al2FeCoNiCrW obtained in step two 0.5 Using high-entropy alloy powder as raw material, a laser cladding method is employed. A high-energy-density laser beam melts the high-entropy alloy powder together with the contact substrate surface material, causing a metallurgical reaction. Finally, rapid cooling and solidification form a high-performance cladding layer. Specifically, cladding is performed on the back of the plowshare according to the dimensional parameters of a prism-type bionic drag-reducing and wear-resistant structure to obtain a prism-type bionic drag-reducing and wear-resistant structure, and cladding is performed on the front of the plowshare according to the dimensional parameters of a convex-hull type bionic drag-reducing and wear-resistant structure to obtain a convex-hull type bionic drag-reducing and wear-resistant structure. After laser cladding, a plowshare with high-entropy alloy powder and a bionic plowshare self-sharpening blade coating is obtained.

[0011] The preparation method for high-entropy alloy powder with a size of 200-300 mesh in step two of the above scheme is as follows: First, use a QXQM-4L planetary ball mill to mix and grind the proportioned Al powder, Fe powder, Co powder, Ni powder, Cr powder, and W powder. The ball-to-powder ratio is 2:1, the ball mill speed is 180 r / min, and the mixing and grinding time is 2.5 h. After the powder mixing test is completed, the mixed powder is collected and placed in a drying oven to dry for 60 min at a temperature of 80℃, to obtain high-entropy alloy powder with a size of 200-300 mesh.

[0012] The laser cladding method in the above scheme is specifically as follows: Al2FeCoNiCrW is prepared using a JSD-3000W continuous fiber laser. 0.5 The high-entropy alloy coating uses a laser with a power of 2000W, a scanning speed of 7 mm / s, a laser spot diameter of 3 mm, a powder feeding speed of 1.2 r / min, and an overlap rate of 40%. Argon gas is introduced during the cladding process to prevent the material from oxidizing at high temperatures, and the argon gas flow rate is 5 L / min.

[0013] In the above scheme, the prism-shaped biomimetic drag-reducing and wear-resistant structure is a prism-shaped geometric structure on the surface of a scallop. The prism cross-section is arc-shaped, the contact surface width between the prism and the substrate is 5mm, the highest point of the prism arc is h=3mm, the prism-shaped biomimetic drag-reducing and wear-resistant structure is located at the lower part of the plowshare in contact with the soil, and the spacing of the prism-shaped biomimetic drag-reducing and wear-resistant structure on the plowshare is 2mm.

[0014] In the above scheme, the convex-shaped biomimetic drag-reducing and wear-resistant structure is a convex-shaped geometric structure of the head of a dung beetle. The bottom diameter of the spherical crown of the convex crown is D=10 mm and the height of the spherical crown is h=2 mm. The convex-shaped biomimetic drag-reducing and wear-resistant structure is located on the upper part of the plowshare in contact with the soil. The distribution density of the convex-shaped biomimetic drag-reducing and wear-resistant structure on the plowshare is 30%. Beneficial effects

[0015] (1) The present invention utilizes laser cladding technology to prepare high-entropy alloy coatings on both sides of the plowshare blade to form two biomimetic surfaces with different wear resistance, thereby making the blade sharper and sharper as it is ground, achieving the effect of self-sharpening. It can realize the combination of laser cladding technology and biomimetic surface technology, effectively improving the wear resistance and drag reduction performance of the plowshare surface.

[0016] (2) The present invention optimizes the composition of high-entropy alloy powder and laser cladding parameters. The cladding layer prepared by the method of the present invention has the characteristics of good macroscopic formability, dense microstructure, high bonding strength, low dilution rate and high hardness, and good wear resistance.

[0017] (3) The present invention optimizes the structure of the biomimetic surface. The biomimetic surface coating prepared by the method of the present invention can effectively improve the anti-soil-sticking ability of the plowshare, thereby effectively achieving the function of wear resistance and drag reduction, and significantly improving the self-sharpening effect of the cutting tool.

[0018] (4) The self-sharpening plowshare prepared by this method can directly improve the reliability, service life and operating efficiency of the whole tillage machinery, reduce the energy consumption of operation, and at the same time, the auxiliary time (replacing the plowshare, maintenance, etc.) is greatly shortened due to the extended fault-free operation time.

[0019] (5) The self-sharpening plowshare prepared by the method of the present invention mainly uses laser cladding technology to prepare a high-entropy alloy coating on the surface of 65Mn steel to form two biomimetic surfaces with different wear resistance, thereby making the blade sharper and sharper as it is sharpened, achieving the effect of self-sharpening. It can realize the combination of laser cladding technology and biomimetic surface technology, effectively improving the wear resistance and drag reduction performance of the plowshare surface.

[0020] (6) The plowshare of the present invention has cladding layers with different wear resistance on both sides, which makes the blades sharper and sharper as they are sharpened, achieving the effect of self-sharpening blades and greatly improving the service life of the plowshare. Attached Figure Description

[0021] Figure 1 This is a picture of the back of a plowshare;

[0022] Figure 2 This is a front view of the plowshare;

[0023] Figure 3 It is a plowshare. Figure 1 ;

[0024] Figure 4 It is a plowshare. Figure 2 ;

[0025] Figure 5 It is a plowshare. Figure 3 ;

[0026] Figure 6 It is a convex hull layout diagram. Detailed Implementation

[0027] This method for preparing a biomimetic plowshare self-sharpening coating based on high-entropy alloy powder includes the following steps:

[0028] Step 1: Pre-treatment of the 65Mn steel substrate surface.

[0029] Step 2: Preparation of Al2FeCoNiCrW 0.5 High-entropy alloy powder, wherein the raw material composition of the high-entropy alloy powder, expressed in molar ratio, is as follows:

[0030] Al:Fe:Co:Ni:Cr:W=2:1:1:1:1:0.5; the size of the high-entropy alloy powder is 200-300 mesh.

[0031] Elements such as Fe, Co, Cr, and Ni are mostly stable elements in the fcc structure. High-entropy alloy coatings composed of these elements have numerous slip systems and a large number of dislocations or twins to support deformation, which is beneficial for improving plasticity. Al is a commonly used alloying element that promotes the transformation of the fcc structure to the bcc structure. It also has good miscibility with other elements, which can suppress the precipitation of the Laves phase and avoid its detrimental effect on plasticity. Furthermore, it readily precipitates coherently with the B2 phase, thus playing a strengthening role. The addition of lightweight Al can enhance the properties of Al2FeCoNiCrW. 0.5 The hardness and strength of high-entropy alloys are significantly increased. Fe element is beneficial to the precipitation of strengthening phases and can significantly improve the mechanical properties of the coating. W element can play a solid solution strengthening role at room temperature, effectively improving the strength, hardness and plasticity of high-entropy alloy coatings.

[0032] Step 3: Prepare the surface biomimetic coating:

[0033] The Al2FeCoNiCrW obtained in step two 0.5Using high-entropy alloy powder as raw material, a laser cladding method is employed. A high-energy-density laser beam melts the high-entropy alloy powder together with the contact substrate surface material, causing a metallurgical reaction. Finally, rapid cooling and solidification form a high-performance cladding layer. Specifically, cladding is performed on the back of the plowshare according to the dimensional parameters of a prism-type bionic drag-reducing and wear-resistant structure to obtain a prism-type bionic drag-reducing and wear-resistant structure, and cladding is performed on the front of the plowshare according to the dimensional parameters of a convex-hull type bionic drag-reducing and wear-resistant structure to obtain a convex-hull type bionic drag-reducing and wear-resistant structure. After laser cladding, a plowshare with high-entropy alloy powder and a bionic plowshare self-sharpening blade coating is obtained.

[0034] High-entropy alloys typically possess high hardness, wear resistance, and excellent corrosion resistance, enabling them to withstand harsh service environments. By coating traditional materials with a high-performance high-entropy alloy protective layer, not only can the application range of traditional materials be expanded and material utilization efficiency improved to control costs, but the superior reliability of high-entropy alloys can also be maximized.

[0035] Laser cladding is a surface modification technique that uses a laser beam to rapidly clad alloy coatings onto a metal surface. High-energy laser irradiation causes the material and substrate to fuse rapidly, and through multiple overlapping layers, a cladding layer of a certain thickness can be formed on the substrate. Compared to other surface modification techniques such as thermal spraying and magnetron sputtering, laser cladding of high-entropy alloy coatings exhibits superior properties such as high bonding strength, low dilution rate, high hardness, good wear resistance, and dense microstructure. Example

[0036] This method for preparing a biomimetic plowshare self-sharpening coating based on high-entropy alloy powder includes the following steps:

[0037] (1) Surface pretreatment:

[0038] The 65Mn steel substrate measures 40×20×10mm. Before cladding, the surface to be clad is ground with an angle grinder to remove oil, rust, and oxide film. Next, 400# SiC sandpaper is used to polish the surface to remove any rotational marks left from the angle grinder until these marks disappear and the surface is uniform and glossy. Anhydrous ethanol is added to an ultrasonic cleaner, and the surface is cleaned for approximately 600 seconds. After cleaning, the surface is placed in a drying oven at 60℃ for 1 hour. After drying, acetone is used to wipe the cladding surface to remove oil again. The substrate is then heated to 200℃ and held at this temperature to reduce cracking. Finally, it is vacuum-sealed in a sealed bag for later use.

[0039] (2) Preparation of high-entropy alloy powder

[0040] The high-entropy alloy powder, in molar ratio, has the following raw material composition:

[0041] Al: Fe:Co: Ni:Cr:W=2:1:1:1:1:0.5.

[0042] To prepare Al2FeCoNiCrW 0.5 The high-entropy alloy powder was first mixed and ground for a long time using a QXQM-4L planetary ball mill to ensure that the powder materials were fully mixed. The ball-to-powder ratio was 2:1, the ball mill speed was 180 r / min, and the mixing and grinding time was 2.5 h.

[0043] After the powder mixing test was completed, the mixed powder was collected and dried in a drying oven at 80℃ for 60 minutes. The size of the high-entropy alloy powder after ball milling was 200-300 mesh.

[0044] (3) Preparation of biomimetic coatings on the surface

[0045] Combining the prismatic geometry of a scallop surface and the convex geometry of a dung beetle's head, using the aforementioned Al2FeCoNiCrW 0.5 Using high-entropy alloy powder as raw material, a laser cladding method is adopted. A high-energy-density laser beam is used to melt the high-entropy alloy powder together with the near-surface material of the substrate, causing a metallurgical reaction. Finally, the powder is rapidly cooled and solidified to form a cladding layer with excellent performance.

[0046] The laser cladding process uses a JSD-3000W continuous fiber laser to prepare Al2FeCoNiCrW. 0.5 High-entropy alloy coating was applied using a laser with a power of 2000W, a scanning speed of 7 mm / s, a laser spot diameter of 3 mm, a powder feeding speed of 1.2 r / min, and an overlap rate of 40%. Argon gas was introduced during the experiment to prevent oxidation of the material at high temperatures, with a flow rate of 5 L / min.

[0047] According to the dimensional parameters of the prism-type biomimetic drag-reducing and wear-resistant structure, the back of the plowshare is clad to obtain the prism-type biomimetic drag-reducing and wear-resistant structure. According to the dimensional parameters of the convex-shaped biomimetic drag-reducing and wear-resistant structure, the front of the plowshare is clad to obtain the convex-shaped biomimetic drag-reducing and wear-resistant structure.

[0048] The plowshare has cladding layers with different wear resistance on both sides, which makes the blades sharper the more they are sharpened, achieving a self-sharpening effect and greatly improving the service life of the plowshare.

[0049] The cross-section of the prism-shaped biomimetic drag-reducing and wear-resistant structure is arc-shaped, the contact surface width between the prism and the substrate is 5mm, the highest point of the arc of the prism is h=3mm, and the prism spacing is 1mm.

[0050] The characteristic dimensions of the convex-shaped biomimetic drag-reducing and wear-resistant structure are: bottom diameter of the spherical cap D=10 mm, height of the spherical cap h=2 mm, and the distribution density of the biomimetic structure on the plowshare is 30%.

[0051] Comparison of this invention with existing technologies:

[0052] (Striped plus convex design compared to ordinary design) Adhesion resistance is reduced by 13%, thickness wear by 77%, length wear by 32%, width wear by 23%, and total wear by 21%. In the table, striped plowshares have ridges on only one side, convex plowshares have convex bumps on only one side, ordinary plowshares have a wear-resistant layer formed on the surface, and striped plus convex design refers to the plowshare prepared by this invention.

[0053] (Strip plus convex to strip) Adhesion resistance is reduced by 50%, thickness wear is reduced by 52%, length wear is reduced by 28%, width wear is reduced by 10%, and total wear is reduced by 11%.

[0054] (Strip-to-convex) Adhesion resistance is reduced by 5%, thickness wear is reduced by 69%, length wear is reduced by 18%, width wear is reduced by 14%, and total wear is reduced by 12%.

[0055] As can be seen, the plowshare prepared by the present invention has cladding layers with different wear resistance on both sides, which makes the blades sharper the more they are sharpened, achieving the effect of self-sharpening and greatly improving the service life of the plowshare.

Claims

1. A method for preparing a biomimetic plowshare self-sharpening coating, characterized in that... Includes the following steps: Step 1: Pre-treatment of the 65Mn steel substrate surface; Step 2: Preparation of Al2FeCoNiCrW 0.5 High-entropy alloy powder, wherein the raw material composition of the high-entropy alloy powder, expressed in molar ratio, is as follows: Al:Fe:Co:Ni:Cr:W=2:1:1:1:1:0.5; the size of the high-entropy alloy powder is 200-300 mesh; Step 3: Prepare the surface biomimetic coating: The Al2FeCoNiCrW obtained in step two 0.5 Using high-entropy alloy powder as raw material, a laser cladding method is employed. A high-energy-density laser beam melts the high-entropy alloy powder together with the surface material of the substrate, causing a metallurgical reaction. Finally, rapid cooling and solidification form a high-performance cladding layer. Specifically, cladding is performed on the back of the plowshare according to the dimensional parameters of a prism-type bionic drag-reducing and wear-resistant structure to obtain a prism-type bionic drag-reducing and wear-resistant structure, and cladding is performed on the front of the plowshare according to the dimensional parameters of a convex-hull type bionic drag-reducing and wear-resistant structure to obtain a convex-hull type bionic drag-reducing and wear-resistant structure. After laser cladding, a surface bionic plowshare self-sharpening blade coating is obtained. The prismatic biomimetic drag-reducing and wear-resistant structure is a prismatic geometric structure on the surface of a scallop. The prismatic cross-section is arc-shaped, the contact surface width between the prismatic structure and the substrate is 5mm, the highest point of the arc of the prismatic structure is h=3mm, the prismatic biomimetic drag-reducing and wear-resistant structure is located at the lower part of the plowshare in contact with the soil, and the spacing of the prismatic biomimetic drag-reducing and wear-resistant structure on the plowshare is 2mm. The convex-shaped biomimetic drag-reducing and wear-resistant structure is a convex-shaped geometric structure of the head of a dung beetle. The bottom diameter of the spherical crown of the convex crown is D=10 mm and the height of the spherical crown is h=2 mm. The convex-shaped biomimetic drag-reducing and wear-resistant structure is located on the upper part of the plowshare in contact with the soil. The distribution density of the convex-shaped biomimetic drag-reducing and wear-resistant structure on the plowshare is 30%.

2. The method for preparing a biomimetic plowshare self-sharpening coating according to claim 1, characterized in that: The preparation method of the high-entropy alloy powder with a size of 200-300 mesh in step two is as follows: First, the Al powder, Fe powder, Co powder, Ni powder, Cr powder, and W powder in the specified ratio are mixed and ground using a QXQM-4L planetary ball mill. The ball-to-powder ratio is 2:1, the ball mill speed is 180 r / min, and the mixing and grinding time is 2.5 h. After the powder mixing test is completed, the mixed powder is collected and placed in a drying oven for drying for 60 min at a temperature of 80℃ to obtain high-entropy alloy powder with a size of 200-300 mesh.

3. The method for preparing a biomimetic plowshare self-sharpening coating according to claim 2, characterized in that: The laser cladding method specifically involves: using a JSD-3000W continuous fiber laser to prepare Al2FeCoNiCrW 0.5 The high-entropy alloy coating uses a laser with a power of 2000W, a scanning speed of 7 mm / s, a laser spot diameter of 3 mm, a powder feeding speed of 1.2 r / min, and an overlap rate of 40%. Argon gas is introduced during the cladding process to prevent the material from oxidizing at high temperatures, and the argon gas flow rate is 5 L / min.

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