Method for preparing laser cladding and heat treatment strengthened fecocrmnmn high-entropy alloy wear-resistant coating

Abstract

The application discloses a preparation method of a laser cladding and heat treatment strengthened FeCoCrNiMn high-entropy alloy wear-resistant coating, and first, a substrate surface is pretreated; then, a FeCoCrNiMn high-entropy alloy coating is prepared through laser cladding; the FeCoCrNiMn high-entropy alloy coating is polished to obtain a smooth surface; finally, annealing treatment is performed to obtain the FeCoCrNiMn high-entropy alloy wear-resistant coating. The application prepares fine-grain FeCoCrNiMn high-entropy alloy with high strength, solves the problems of low relative hardness, poor wear resistance of the FeCoCrNiMn high-entropy alloy, and in particular solves the technical problems that the production and application of large-area coating cannot be realized through traditional metallurgical preparation technology.

Description

Technical Field

[0001] This invention belongs to the field of FeCoCrNiMn high-entropy alloy wear-resistant coating preparation technology, specifically involving a method for preparing FeCoCrNiMn high-entropy alloy wear-resistant coatings strengthened by laser cladding and heat treatment. Background Technology

[0002] High-entropy alloys, with their near-equimolar proportions of major elements, can easily form single-phase solid solutions with face-centered cubic (FCC), body-centered cubic (BCC), or hexagonal close-packed (HCP) structures by precisely controlling the composition and content of these elements. These alloys exhibit excellent properties such as high hardness / strength, high fatigue resistance and fracture toughness, high-temperature oxidation resistance, and corrosion resistance. In recent years, FeCoCrNiMn alloys have attracted widespread attention due to their stable FCC single-phase structure and excellent machinability, and are considered excellent materials for aerospace and marine equipment manufacturing. However, their low hardness and poor wear resistance limit their application in tribology. Based on the relationship between microstructure and properties, FeCoCrNiMn can be strengthened and toughened through processes such as altering its internal microstructure. For example, adding a sixth element can induce a transformation from a FCC to a BCC structure, increasing grain dislocation and improving surface hardness and wear resistance. However, this technology involves a long process and the process parameters have a significant impact on the alloy properties, resulting in high costs.

[0003] Laser cladding involves simultaneously melting a substrate and powder using a high-energy-density laser beam under a protective atmosphere to form a molten pool, followed by rapid cooling to obtain a cladding layer with superior strength, impact resistance, and corrosion resistance compared to the original substrate. Laser cladding can significantly improve the overall performance of alloy materials by preparing high-entropy alloy coatings on them. Therefore, this invention proposes a method for synergistically preparing FeCoCrNiMn high-entropy alloy wear-resistant coatings using laser cladding and heat treatment processes. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing wear-resistant coatings of FeCoCrNiMn high-entropy alloy strengthened by laser cladding and heat treatment. This method produces a high-strength, fine-grained FeCoCrNiMn high-entropy alloy, which solves the problems of low relative hardness, poor wear resistance, and, in particular, the difficulty of producing and applying large-area coatings using traditional metallurgical preparation techniques.

[0005] The technical solution adopted in this invention is a method for preparing a FeCoCrNiMn high-entropy alloy wear-resistant coating strengthened by laser cladding and heat treatment, which is implemented according to the following steps:

[0006] Step 1: Pretreatment of the substrate surface;

[0007] Step 2: Laser cladding to prepare FeCoCrNiMn high-entropy alloy coating;

[0008] Step 3: Grind and polish the FeCoCrNiMn high-entropy alloy coating to obtain a smooth surface;

[0009] Step 4: Annealing treatment to obtain FeCoCrNiMn high-entropy alloy wear-resistant coating.

[0010] The invention is further characterized in that,

[0011] Step 1 is implemented in the following steps:

[0012] Step 1.1: Grind the sample surface to remove the oxide layer;

[0013] Step 1.2: Clean the substrate obtained in Step 1 to remove surface grease, organic matter, and metal residue;

[0014] Step 1.3: Rinse the substrate surface after step 1.2 to remove residual anhydrous ethanol, and let the surface dry before use.

[0015] Step 2 is implemented in the following steps:

[0016] Step 2.1: Weigh out cladding powder containing 15%-25% Fe, 15%-20% Cr, 15%-25% Ni, 15%-25% Mn, and 15%-20% Co. The sum of the mass percentages of the above powders is 100%, the purity of the powders is greater than 99%, and the particle size range is 100-250 μm.

[0017] Step 2.2: Stir for 2-6 hours to make the powder diameter range 50-100μm.

[0018] Step 2.3: Dry the mixed powder after step 2.2, and after the heat preservation is completed, cool it down to room temperature and take it out.

[0019] Step 2.4: Place the dried FeCoCrNiMn high-entropy alloy powder into a powder feeder, and spray the powder onto the surface to be clad using a powder feeding gas, which is an inert gas such as nitrogen or argon.

[0020] Step 2.5: Use a high-speed laser cladding device to clad the substrate surface to form a FeCoCrNiMn high-entropy alloy coating. Laser power: 1-2.5kW, scanning speed: 2-3m / min, powder feeding rate: 12-13g / min.

[0021] In step 2.3, the drying temperature is 80℃-150℃, and the holding time is 4h-14h.

[0022] Step 3 is implemented in the following steps:

[0023] The FeCoCrNiMn high-entropy alloy coating surface obtained in step 2 is treated using the method in step 1 to finally obtain a smooth FeCoCrNiMn high-entropy alloy coating surface.

[0024] Step 4 is implemented in the following steps:

[0025] Step 4.1: Prepare the specimen with FeCoCrNiMn high-entropy alloy coating obtained in Step 3 for annealing treatment;

[0026] Step 4.2: Set the resistance furnace temperature to 500-900℃ and start heating to gradually raise the furnace temperature to the set temperature, and use nitrogen as the protective gas inside the furnace.

[0027] Step 4.3: Anneal at 500–900℃ for 2–14 hours;

[0028] Step 4.4: After the heat preservation is completed, stop heating and allow the furnace to cool naturally to obtain the FeCoCrNiMn high-entropy alloy wear-resistant coating.

[0029] The beneficial effects of this invention are as follows: the method for preparing FeCoCrNiMn high-entropy alloy wear-resistant coatings strengthened by laser cladding and heat treatment has the following advantages: (1) The high-entropy alloy coating prepared by laser cladding has the advantages of concentrated energy, fast cooling rate, low dilution rate, and small heat-affected zone, thereby preparing a high-density large-area coating, while reducing the amount of high-entropy alloy powder used and improving economy. (2) The alloy coating strengthened by annealing has excellent surface hardness, which can effectively improve wear resistance and service life. (3) Since the preparation process is simple and economical, and no other complex equipment is required, it has great application potential in industrial production. Attached Figure Description

[0030] Figure 1 Examples 1, 2, and 3 of the method for preparing FeCoCrNiMn high-entropy alloy wear-resistant coatings strengthened by laser cladding and heat treatment according to the present invention show the surface metallographic morphology.

[0031] Figure 2 These are the friction coefficient curves of Examples 1, 2, and 3 of the method for preparing FeCoCrNiMn high-entropy alloy wear-resistant coatings strengthened by laser cladding and heat treatment according to the present invention;

[0032] Figure 3 The volume wear rates of Examples 1, 2, and 3 of the method for preparing FeCoCrNiMn high-entropy alloy wear-resistant coatings strengthened by laser cladding and heat treatment according to the present invention are shown.

[0033] Figure 4 The microhardness of Examples 1, 2, and 3 of the method for preparing FeCoCrNiMn high-entropy alloy wear-resistant coatings strengthened by laser cladding and heat treatment according to the present invention is shown. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0035] The present invention discloses a method for preparing a wear-resistant coating of FeCoCrNiMn high-entropy alloy strengthened by laser cladding and heat treatment, which is specifically implemented according to the following steps:

[0036] Step 1: Pretreatment of the substrate surface;

[0037] Step 1 is implemented in the following steps:

[0038] Step 1.1: Use 200#, 600#, and 800# metallographic sandpaper in sequence to polish the sample surface and remove the oxide layer.

[0039] Step 1.2: Clean the substrate obtained in Step 1 in an ultrasonic cleaner using anhydrous ethanol as a solvent for 5-10 minutes to remove surface grease, organic matter, and metal residue.

[0040] Step 1.3: Rinse the substrate surface after step 1.2 with deionized water to remove residual anhydrous ethanol. Allow the surface to dry before use.

[0041] Step 2: Laser cladding to prepare FeCoCrNiMn high-entropy alloy coating;

[0042] Step 2 is implemented in the following steps:

[0043] Step 2.1: Weigh out cladding powder containing 15%-25% Fe, 15%-20% Cr, 15%-25% Ni, 15%-25% Mn, and 15%-20% Co. The sum of the mass percentages of the above powders is 100%, the purity of the powders is greater than 99%, and the particle size range is 100-250 μm.

[0044] Step 2.2: To ensure good powder flowability, place the mixed powder into a ball mill jar and stir it in a planetary vertical ball mill at a speed of 50-500 r / min for 2-6 hours to achieve a powder diameter range of 50-100 μm.

[0045] Step 2.3: Dry the mixed powder obtained in Step 2.2 in a drying oven under nitrogen or argon protection at a temperature of 80℃-150℃ for 4-14 hours to remove moisture and volatile substances from the powder. After the drying period, continuously introduce nitrogen or argon into the drying oven for cooling until it reaches room temperature, then remove the powder.

[0046] Step 2.4: Place the dried FeCoCrNiMn high-entropy alloy powder into a powder feeder, and spray the powder onto the surface to be clad using a powder feeding gas, which is an inert gas such as nitrogen or argon.

[0047] Step 2.5: Use a high-speed laser cladding device to clad the substrate surface to form a FeCoCrNiMn high-entropy alloy coating. Laser power: 1-2.5kW, scanning speed: 2-3m / min, powder feeding rate: 12-13g / min.

[0048] Step 3: Grind and polish the FeCoCrNiMn high-entropy alloy coating to obtain a smooth surface;

[0049] Step 3 is implemented in the following steps:

[0050] The FeCoCrNiMn high-entropy alloy coating surface obtained in step 2 is treated using the method in step 1, as detailed in step 1; finally, a smooth surface of the FeCoCrNiMn high-entropy alloy coating is obtained.

[0051] Step 4: Annealing treatment to obtain FeCoCrNiMn high-entropy alloy wear-resistant coating;

[0052] Step 4 is implemented in the following steps:

[0053] Step 4.1: Place the specimen with the FeCoCrNiMn high-entropy alloy coating obtained in Step 3 into a box-type resistance furnace in preparation for annealing.

[0054] Step 4.2: Set the resistance furnace temperature to 500-900℃ and start heating to gradually raise the furnace temperature to the set temperature, and use nitrogen as the protective gas inside the furnace.

[0055] Step 4.3: Anneal at 500–900℃ for 2–14 hours;

[0056] Step 4.4: After the heat preservation is completed, stop heating and allow the furnace to cool naturally to obtain the FeCoCrNiMn high-entropy alloy wear-resistant coating.

[0057] To investigate the influence of annealing process parameters on the wear-resistant properties of the FeCoCrNiMn high-entropy alloy coating, surface hardness was tested using a microhardness tester with a load of 50g applied for 15s. Dry friction experiments were then conducted to characterize the wear resistance of the FeCoCrNiMn high-entropy alloy coating. The load was set at 5N, the sliding speed at 0.04m / s, the reciprocating distance at 5mm, and the experimental time at 30min. To ensure experimental accuracy, the steel ball and disc samples were ultrasonically cleaned with anhydrous ethanol before and after the experiment, and then dried to remove oil and other impurities from the sample surfaces. After the experiment, the wear track profile was measured using a laser confocal microscope, and the volumetric wear rate was calculated. Through the above tests, the high-entropy alloy wear-resistant coating of this invention exhibits excellent wear resistance.

[0058] Example 1

[0059] The specimen selected for preparing the FeCoCrNiMn high-entropy alloy wear-resistant coating was 10 mm thick 45 steel, specifically a 20×20×5 mm 45 steel sample. The following are specific examples of the preparation of the FeCoCrNiMn high-entropy alloy wear-resistant coating.

[0060] The present invention provides a method for preparing a FeCoCrNiMn high-entropy alloy wear-resistant coating, which can be achieved through the following technical solution:

[0061] Step 1: Pretreatment of the substrate surface;

[0062] Step 1 is as follows:

[0063] Step 1.1: Use 200#, 600#, and 800# metallographic sandpaper in sequence to polish the sample surface and remove the oxide layer.

[0064] Step 1.2: Clean the substrate obtained in Step 1 in an ultrasonic cleaner using anhydrous ethanol as a solvent for 5-10 minutes to remove surface grease, organic matter, and metal residue.

[0065] Step 1.3: Rinse the substrate surface after step 1.2 with deionized water to remove residual anhydrous ethanol. Allow the surface to dry before use.

[0066] Step 2 involves cladding FeCoCrNiMn high-entropy alloy onto the substrate surface.

[0067] Step 2 is as follows:

[0068] Step 2.1: The FeCoCrNiMn high-entropy alloy powder has the following chemical composition: Fe: 15%-25%, Cr: 15%-20%, Ni: 15%-25%, Mn: 15%-25%, Co: 15%-20%. The powder has a purity greater than 99% and a particle size range of 100-250 μm.

[0069] Step 2.2: To ensure good powder flowability, place the mixed powder into a ball mill jar and stir it in a planetary vertical ball mill at a speed of 50-500 r / min for 2-6 hours to achieve a powder diameter range of 50-100 μm.

[0070] Step 2.3: Dry the FeCoCrNiMn high-entropy alloy powder in a drying oven under nitrogen or argon protection. The drying temperature is 80℃-150℃, and the holding time is 4h-14h to remove moisture and volatile substances from the powder. After the holding time is completed, nitrogen or argon is continuously introduced into the drying oven for cooling. After cooling to room temperature, the powder is removed.

[0071] Step 2.4: Place the dried FeCoCrNiMn high-entropy alloy powder into a powder feeder, and spray the powder onto the surface to be clad using a powder feeding gas, which is an inert gas such as nitrogen or argon.

[0072] Step 2.5: Prepare FeCoCrNiMn high-entropy alloy coating using high-speed laser cladding equipment. Laser power: 1-82.33kW, scanning speed: 2.90m / min, powder feeding rate: 12.46g / min.

[0073] Step 3 involves grinding and polishing the surface of the laser-clad sample.

[0074] Step 3 is as follows:

[0075] Step 3.1: The surface of the cladding layer obtained in Step 2 is treated using the method in Step 1. See Step 2 for details.

[0076] Step 4 is annealing to obtain a FeCoCrNiMn high-entropy alloy wear-resistant coating;

[0077] Step 4 is as follows:

[0078] Step 4.1: Place the high-entropy alloy specimen obtained in Step 3 into a box-type resistance furnace;

[0079] Step 4.2: Set the resistance furnace temperature to 700℃ and start the heating system to gradually raise the furnace temperature to the set temperature, and use nitrogen as the protective gas inside the furnace.

[0080] Step 4.3: Anneal at 700℃ for 2 hours;

[0081] Step 4.4: After the heat preservation is completed, turn off the heating system of the resistance furnace and allow it to cool naturally with the furnace.

[0082] A high-entropy alloy wear-resistant coating of FeCoCrNiMn was subsequently obtained. For example... Figure 1Wherein (a) is the surface morphology of Example 1, (b) is the surface morphology of Example 2, (c) is the surface morphology of Example 3, (d) is the grain size frequency distribution diagram of Example 1, (e) is the grain size frequency distribution diagram of Example 2, and (f) is the grain size frequency distribution diagram of Example 3. Figure 1 It can be seen that approximately 76% of the grains on the sample surface after annealing at 700℃ for 2 hours have a grain size smaller than 150 μm, and all grains have a size smaller than 250 μm. Figure 2 As can be seen, the friction coefficient curve of Example 1 fluctuates quite drastically, with a fluctuation amplitude of approximately 0.15, and its average friction coefficient is 0.706. Figure 3 and Figure 4 It can be seen that after the friction test of 5N-4Hz, the volumetric wear rate of the coating is approximately 1.35×10⁻⁶. -4 The surface microhardness is approximately 240.5 HV. In summary, the high-entropy alloy wear-resistant coating preparation technology of this invention can refine the FeCoCrNiMn coating grains and improve wear resistance.

[0083] Example 2

[0084] The specimen selected for preparing the FeCoCrNiMn high-entropy alloy wear-resistant coating was 10 mm thick 45 steel, specifically a 20×20×5 mm 45 steel sample. The following are specific examples of the preparation of the FeCoCrNiMn high-entropy alloy wear-resistant coating.

[0085] The present invention provides a method for preparing a FeCoCrNiMn high-entropy alloy wear-resistant coating, which can be achieved through the following technical solution:

[0086] Step 1: Pretreatment of the substrate surface;

[0087] Step 1 is as follows:

[0088] Step 1.1: Use 200#, 600#, and 800# metallographic sandpaper in sequence to polish the sample surface and remove the oxide layer.

[0089] Step 1.2: Clean the substrate obtained in Step 1 in an ultrasonic cleaner using anhydrous ethanol as a solvent for 5-10 minutes to remove surface grease, organic matter, and metal residue.

[0090] Step 1.3: Rinse the substrate surface after step 1.2 with deionized water to remove residual anhydrous ethanol. Allow the surface to dry before use.

[0091] Step 2 involves cladding FeCoCrNiMn high-entropy alloy onto the substrate surface.

[0092] Step 2 is as follows:

[0093] Step 2.1: The FeCoCrNiMn high-entropy alloy powder has the following chemical composition: Fe: 15%-25%, Cr: 15%-20%, Ni: 15%-25%, Mn: 15%-25%, Co: 15%-20%. The powder has a purity greater than 99% and a particle size range of 100-250 μm.

[0094] Step 2.2: To ensure good powder flowability, place the mixed powder into a ball mill jar and stir it in a planetary vertical ball mill at a speed of 50-500 r / min for 2-6 hours to achieve a powder diameter range of 50-100 μm.

[0095] Step 2.3: Dry the FeCoCrNiMn high-entropy alloy powder in a drying oven under nitrogen or argon protection. The drying temperature is 80℃-150℃, and the holding time is 4h-14h to remove moisture and volatile substances from the powder. After the holding time is completed, nitrogen or argon is continuously introduced into the drying oven for cooling. After cooling to room temperature, the powder is removed.

[0096] Step 2.4: Place the dried FeCoCrNiMn high-entropy alloy powder into a powder feeder, and spray the powder onto the surface to be clad using a powder feeding gas, which is an inert gas such as nitrogen or argon.

[0097] Step 2.5: Prepare FeCoCrNiMn high-entropy alloy coating using high-speed laser cladding equipment. Laser power: 1-82.33kW, scanning speed: 2.90m / min, powder feeding rate: 12.46g / min.

[0098] Step 3 involves grinding and polishing the surface of the laser-clad sample.

[0099] Step 3 is as follows:

[0100] Step 3.1: The surface of the cladding layer obtained in Step 2 is treated using the method in Step 1. See Step 2 for details.

[0101] Step 4 is annealing to obtain a FeCoCrNiMn high-entropy alloy wear-resistant coating;

[0102] Step 4 is as follows:

[0103] Step 4.1: Place the high-entropy alloy specimen obtained in Step 3 into a box-type resistance furnace;

[0104] Step 4.2: Set the resistance furnace temperature to 700℃ and start the heating system to gradually raise the furnace temperature to the set temperature, and use nitrogen as the protective gas inside the furnace.

[0105] Step 4.3: Anneal at 700℃ for 8 hours;

[0106] Step 4.4: After the heat preservation is completed, turn off the heating system of the resistance furnace and allow it to cool naturally with the furnace.

[0107] A high-entropy alloy wear-resistant coating of FeCoCrNiMn was subsequently obtained. Figure 1 It can be seen that approximately 79.6% of the grains on the coating surface are below 150 μm in size, while 96% are below 250 μm. Figure 2 It can be seen that the friction coefficient of the sample annealed at 700℃ for 8 hours increased rapidly to 0.65 at the beginning of the experiment, decreased to 0.55 after a short break-in period, and then began to increase again, with an average friction coefficient of 0.635. Figure 3 and Figure 4 As can be seen, the volumetric wear rate of the coating is approximately 8.14 × 10⁻⁵ mm³ / N·m, and the microhardness is approximately 250.8 HV. In summary, the high-entropy alloy wear-resistant coating preparation technology of this invention can improve the hardness and wear resistance of the FeCoCrNiMn coating.

[0108] Example 3

[0109] The specimen selected for preparing the FeCoCrNiMn high-entropy alloy wear-resistant coating was 10 mm thick 45 steel, specifically a 20×20×5 mm 45 steel sample. The following are specific examples of the preparation of the FeCoCrNiMn high-entropy alloy wear-resistant coating.

[0110] The present invention provides a method for preparing a FeCoCrNiMn high-entropy alloy wear-resistant coating, which can be achieved through the following technical solution:

[0111] Step 1: Pretreatment of the substrate surface;

[0112] Step 1 is as follows:

[0113] Step 1.1: Use 200#, 600#, and 800# metallographic sandpaper in sequence to polish the sample surface and remove the oxide layer.

[0114] Step 1.2: Clean the substrate obtained in Step 1 in an ultrasonic cleaner using anhydrous ethanol as a solvent for 5-10 minutes to remove surface grease, organic matter, and metal residue.

[0115] Step 1.3: Rinse the substrate surface after step 1.2 with deionized water to remove residual anhydrous ethanol. Allow the surface to dry before use.

[0116] Step 2 involves cladding FeCoCrNiMn high-entropy alloy onto the substrate surface.

[0117] Step 2 is as follows:

[0118] Step 2.1: The FeCoCrNiMn high-entropy alloy powder has the following chemical composition: Fe: 15%-25%, Cr: 15%-20%, Ni: 15%-25%, Mn: 15%-25%, Co: 15%-20%. The powder has a purity greater than 99% and a particle size range of 100-250 μm.

[0119] Step 2.2: To ensure good powder flowability, place the mixed powder into a ball mill jar and stir it in a planetary vertical ball mill at a speed of 50-500 r / min for 2-6 hours to achieve a powder diameter range of 50-100 μm.

[0120] Step 2.3: Dry the FeCoCrNiMn high-entropy alloy powder in a drying oven under nitrogen or argon protection. The drying temperature is 80℃-150℃, and the holding time is 4h-14h to remove moisture and volatile substances from the powder. After the holding time is completed, nitrogen or argon is continuously introduced into the drying oven for cooling. After cooling to room temperature, the powder is removed.

[0121] Step 2.4: Place the dried FeCoCrNiMn high-entropy alloy powder into a powder feeder, and spray the powder onto the surface to be clad using a powder feeding gas, which is an inert gas such as nitrogen or argon.

[0122] Step 2.5: Prepare FeCoCrNiMn high-entropy alloy coating using high-speed laser cladding equipment. Laser power: 1-82.33kW, scanning speed: 2.90m / min, powder feeding rate: 12.46g / min.

[0123] Step 3 involves grinding and polishing the surface of the laser-clad sample.

[0124] Step 3 is as follows:

[0125] Step 3.1: The surface of the cladding layer obtained in Step 2 is treated using the method in Step 1. See Step 2 for details.

[0126] Step 4 is annealing to obtain a FeCoCrNiMn high-entropy alloy wear-resistant coating;

[0127] Step 4 is as follows:

[0128] Step 4.1: Place the high-entropy alloy specimen obtained in Step 3 into a box-type resistance furnace;

[0129] Step 4.2: Set the resistance furnace temperature to 700℃ and start the heating system to gradually raise the furnace temperature to the set temperature, and use nitrogen as the protective gas inside the furnace.

[0130] Step 4.3: Anneal at 700℃ for 14 hours;

[0131] Step 4.4: After the heat preservation is completed, turn off the heating system of the resistance furnace and allow it to cool naturally with the furnace.

[0132] As can be seen from the attached diagram, Figure 1 (a) shows the surface morphology of Example 1, (b) shows the surface morphology of Example 2, (c) shows the surface morphology of Example 3, (d) shows the grain size frequency distribution of Example 1, (e) shows the grain size frequency distribution of Example 2, and (f) shows the grain size frequency distribution of Example 3. Figure 2 These are the friction coefficient curves of Examples 1, 2, and 3 of the method for preparing FeCoCrNiMn high-entropy alloy wear-resistant coatings strengthened by laser cladding and heat treatment according to the present invention; Figure 3 The volume wear rates of Examples 1, 2, and 3 of the method for preparing FeCoCrNiMn high-entropy alloy wear-resistant coatings strengthened by laser cladding and heat treatment according to the present invention are shown. Figure 4 The microhardness of Examples 1, 2, and 3 of the method for preparing the FeCoCrNiMn high-entropy alloy wear-resistant coating strengthened by laser cladding and heat treatment according to the present invention is shown in the attached figures. As can be seen from the figures above, approximately 69.4% of the grain size on the coating surface is below 150 μm, and 93% is below 250 μm. The coating annealed at 700℃ for 14 hours exhibits a more stable friction coefficient curve throughout the experiment, with an average friction coefficient of 0.670 and a volumetric wear rate of approximately 2.76 × 10⁻⁴ mm. 3 The microhardness is approximately 185.4 HV per N·m. This demonstrates that the high-entropy alloy wear-resistant coating preparation technology of this invention can improve the tribological properties of FeCoCrNiMn.

Claims

1. A method for preparing a wear-resistant coating of FeCoCrNiMn high-entropy alloy strengthened by laser cladding and heat treatment, characterized in that, The specific steps are as follows: Step 1: Pretreatment of the substrate surface; Step 1 is implemented in the following steps: Step 1.1: Use 200#, 600#, and 800# metallographic sandpaper in sequence to polish the sample surface and remove the oxide layer. Step 1.2: Clean the substrate obtained in Step 1 in an ultrasonic cleaner using anhydrous ethanol as the solvent for 5-10 minutes to remove surface grease, organic matter, and metal residue. Step 1.3: Rinse the substrate surface after step 1.2 with deionized water to remove residual anhydrous ethanol. Allow the surface to dry before use. Step 2: Laser cladding is used to prepare a FeCoCrNiMn high-entropy alloy coating; Step 2 is implemented in the following steps: Step 2.1: Weigh out cladding powder with Fe: 15%-25%, Cr: 15%-20%, Ni: 15%-25%, Mn: 15%-25%, and Co: 15%-20%, the sum of the mass percentages of the above powders is 100%, the purity of the powders is greater than 99%, and the particle size range is 100-250μm; Step 2.2: Place the mixed powder into a ball mill jar, and then stir it in a planetary vertical ball mill at a speed of 50-500 r / min for 2h-6h to make the powder diameter range 50-100μm; Step 2.3: Dry the mixed powder after step 2.2, and after the heat preservation is completed, cool it down to room temperature and take it out; the drying temperature in step 2.3 is 80℃-150℃, and the heat preservation time is 4h-14h. Step 2.4: Place the dried FeCoCrNiMn high-entropy alloy powder into a powder feeder, and spray the powder onto the surface to be clad using a powder feeding gas, which is an inert gas such as nitrogen or argon. Step 2.5: Use a high-speed laser cladding device to clad the substrate surface to form a FeCoCrNiMn high-entropy alloy coating. Laser power: 1-82.33kW, scanning speed: 2.90m / min, powder feeding rate: 12.46g / min; Step 3: Grind and polish the FeCoCrNiMn high-entropy alloy coating to obtain a smooth surface; Step 3 is implemented in the following steps: The FeCoCrNiMn high-entropy alloy coating surface obtained in step 2 is treated using the method in step 1 to finally obtain a smooth FeCoCrNiMn high-entropy alloy coating surface. Step 4: Annealing treatment to obtain FeCoCrNiMn high-entropy alloy wear-resistant coating; Step 4 is implemented in the following steps: Step 4.1: Place the high-entropy alloy specimen obtained in Step 3 into a box-type resistance furnace; Step 4.2: Set the resistance furnace temperature to 700℃ and start the heating system to gradually raise the furnace temperature to the set temperature, and use nitrogen as the protective gas inside the furnace. Step 4.3: Anneal at 700℃ for 8 hours; Step 4.4: After the heat preservation is completed, turn off the resistance furnace heating system and allow the furnace to cool naturally to obtain the FeCoCrNiMn high-entropy alloy wear-resistant coating.

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