High-entropy base material nano coating cutting tool and preparation method thereof

Abstract

The invention belongs to the technical field of metallurgy. The invention relates to a cutting tool, in particular to a high-entropy base material nano-coating cutting tool and a preparation method thereof. The preparation method comprises the following steps: purifying the surface of the cutter to remove grease and rust on the surface; performing roughening treatment on the surface of the cutter; then the tool is preheated to obtain a pretreated tool; after a spraying material is heated to a molten state, thermal spraying is conducted on the surface of the pretreated tool, then the tool is cooled to the room temperature, and a spraying tool is obtained; the spraying material comprises a metal alloy and a non-metal material; the mass ratio of the metal alloy to the non-metal material is (55-60): 1; the metal alloy comprises Al, Co, Cr, Fe, Ni and La; wherein the molar ratio of Al to Co to Cr to Fe to Ni to La is 1: 1: 1: 1: 1: 0.06; the non-metallic material is nano silicon dioxide; and after the spraying cutter is subjected to heat treatment, the spraying cutter is cooled to the room temperature, then grinding and polishing are conducted, and the high-entropy base material nanometer coating cutter is obtained.

Description

Technical Field

[0001] The present invention belongs to the field of metallurgical technology and more specifically relates to a high entropy substrate nano-coated tool and a preparation method thereof. Background Art

[0002] High-entropy substrate nano-multilayer coated tools are called "high-entropy" because their coating materials use high-entropy alloys. Such alloys are usually composed of five or more main elements mixed in roughly equal proportions. This combination of multiple elements brings higher configuration entropy, thus forming unique material properties and advantages.

[0003] High strength and high toughness: Due to the multi-element composition of high-entropy alloys, they often exhibit better mechanical properties than traditional alloys, including higher strength and good plasticity; High heat resistance: High-entropy alloys can maintain their structure and performance in high-temperature environments and are suitable for extreme working conditions, such as high-speed cutting tools; Excellent wear resistance: High-entropy alloys have high hardness and elastic modulus, which gives them a longer service life under friction and wear conditions; Corrosion resistance: Some high-entropy alloys exhibit good corrosion resistance and are suitable for use in harsh environments; Oxidation resistance: High-entropy alloys have good oxidation resistance at high temperatures, which is crucial to improving the durability and reliability of tools.

[0004] High entropy substrate nano-multilayer coating tools take advantage of these advantages and play an important role in improving cutting efficiency, extending tool life and maintaining performance stability in harsh working environments.

[0005] At present, the main methods for preparing high-entropy alloy coatings are thermal spraying, laser cladding, and magnetron sputtering. Referring to existing research, magnetron sputtering and laser cladding are the most common methods for preparing high-entropy alloy coatings. The prepared coatings are dense, have high bonding strength with the substrate, and have a relatively stable structure. The high-entropy alloy coatings prepared by thermal spraying are of poorer quality than the other two methods, and impurities such as oxides will be produced during the spraying process, and the structure is prone to change. Among them, thermal spraying technology is suitable for large-scale production due to its advantages such as easy control, low cost, convenience for industrial mass production, and less impact on the substrate, and has great potential for industrial application. Summary of the invention

[0006] The technical problem to be solved by the present invention is that a high entropy substrate nano-coating formed by thermal spraying on the surface of a tool may fall off during long-term use of the product and have insufficient bonding strength with the tool substrate. The present invention provides a high entropy substrate nano-coating tool and a preparation method thereof.

[0007] The purpose of the invention is to provide a high entropy substrate nano-coated tool.

[0008] Another object of the present invention is to provide a method for preparing a high entropy substrate nano-coated tool.

[0009] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0010] A method for preparing a high entropy substrate nano-coated tool, the specific preparation steps comprising:

[0011] Surface treatment of tool substrate:

[0012] Clean the surface of the tool to remove surface grease and rust;

[0013] Then the surface of the tool is roughened;

[0014] The tool is then preheated to obtain a pretreated tool;

[0015] Surface spraying:

[0016] After the spraying material is heated to a molten state, thermal spraying is performed on the surface of the pre-treated tool, and then cooled to room temperature to obtain a sprayed tool;

[0017] The spraying material includes metal alloy and non-metallic material;

[0018] The mass ratio of the metal alloy to the non-metallic material is (55-60):1;

[0019] The metal alloy includes Al, Co, Cr, Fe, Ni and La;

[0020] Among them, the molar ratio of Al:Co:Cr:Fe:Ni:La is 1:1:1:1:1:0.06;

[0021] The non-metallic material is nano silicon dioxide;

[0022] Post-processing:

[0023] The sprayed tool is heat treated, cooled to room temperature, and then ground and polished to obtain a high entropy substrate nano-coated tool.

[0024] Further, the surface cleaning includes:

[0025] Use 8-10% sodium carbonate solution to clean the tool surface 3-5 times to remove surface grease;

[0026] After rinsing with clean water for 3-5 times, clean the tool surface for 3-5 times with a hydrochloric acid solution with a mass fraction of 0.3-0.5% to remove surface rust.

[0027] Furthermore, the roughening treatment includes:

[0028] The tool surface is sandblasted to adjust the tool surface roughness Ra to 2.5-2.8mm.

[0029] Further, the preheating includes:

[0030] Preheat to 400-420℃ and keep warm.

[0031] Furthermore, the D50 of the nano-silicon dioxide is 80-90 nm; and the particle size distribution range of the nano-silicon dioxide is 30-150 nm.

[0032] Furthermore, the spraying material also includes 2-5% of the mass of the metal alloy nano manganese dioxide; the D50 of the nano manganese dioxide is 20-25nm.

[0033] Further, the heat treatment includes:

[0034] Under inert atmosphere, heat to 480-500°C at a rate of 4-6°C / min and keep heat treatment for 80-120 minutes.

[0035] A high entropy substrate nano-coated cutting tool is prepared by the above-mentioned preparation method.

[0036] Beneficial effects:

[0037] (1) The above technical solution introduces La into the metal alloy system, and the metal alloy includes Al. Thus, during the product processing, La can be used to induce the oxide on the outer surface to preferentially form a dense α-Al 2 O 3 , thus effectively avoiding further oxidation of the coating and reducing the oxygen content of the overall coating. In addition, dense α-Al 2 O 3 The formation of can effectively improve the density of the coating, thereby reducing the porosity, and in this way, improve the adhesion of the coating to the tool substrate;

[0038] (2) In addition, the inventors found that by introducing a certain amount of silica into the system, the silica particles can effectively fill the pores in the coating during the thermal spraying process, reduce the porosity, and thus improve the density of the coating. This filling effect can be combined with the dense α-Al 2 O 3 The two elements work together to effectively block the penetration pathways of corrosive media on the surface and inside of the product, thereby increasing the service life of the coating. Furthermore, the introduction of La can work together with silica and manganese dioxide to affect the phase separation behavior of the coating during the curing process, helping to form a more uniform microstructure and reduce microcracks and holes caused by phase separation, thereby effectively improving the adhesion of the coating to the substrate. DETAILED DESCRIPTION

[0039] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0040] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0041] Example 1

[0042] Surface treatment of tool substrate:

[0043] The general high-speed steel W18Cr4V is used as the tool base material;

[0044] At a temperature of 25°C, the surface of the tool substrate was cleaned three times with an 8% sodium carbonate solution to remove surface grease.

[0045] After rinsing with clean water for 3 times, the surface of the tool substrate was cleaned with a hydrochloric acid solution with a mass fraction of 0.3% for 3 times to remove the surface rust, and then rinsed with clean water for 2 times to remove the residual hydrochloric acid solution to complete the surface purification of the tool substrate;

[0046] Then, the cleaned tool substrate is sandblasted to adjust the roughness Ra of the tool surface to 2.5 mm to complete the roughening treatment of the tool substrate;

[0047] Then, the roughened tool substrate is preheated to 400° C. in a nitrogen atmosphere and kept warm to complete the preheating of the tool, thereby obtaining a pretreated tool;

[0048] Surface spraying:

[0049] After the spraying material is heated to a molten state, plasma thermal spraying is performed on the surface of the pretreated tool under argon protection, and the coating thickness is controlled to be 0.65 mm. Then, the coating is cooled to room temperature to obtain a sprayed tool.

[0050] Among them, the plasma thermal spraying power is 30kW, the spraying distance is 100mm, the spraying angle is 70°, and the single spraying thickness is 0.01mm;

[0051] The spraying material includes metal alloy, non-metal material and nano manganese dioxide;

[0052] The mass ratio of the metal alloy and the non-metallic material is 55:1;

[0053] The metal alloy includes Al, Co, Cr, Fe, Ni and La;

[0054] Among them, the molar ratio of Al:Co:Cr:Fe:Ni:La is 1:1:1:1:1:0.06;

[0055] The non-metallic material is nano-silicon dioxide; the D50 of the nano-silicon dioxide is 80nm; and the particle size distribution range of the nano-silicon dioxide is 30-150nm;

[0056] The mass of the nano manganese dioxide is 2% of the mass of the metal alloy; the D50 of the nano manganese dioxide is 20nm;

[0057] Post-processing:

[0058] The sprayed tool was heated to 480°C at a rate of 4°C / min under inert atmosphere, heat treated for 80 minutes, cooled to room temperature, and then ground and polished to obtain a high entropy substrate nano-coated tool.

[0059] Example 2

[0060] Surface treatment of tool substrate:

[0061] The general high-speed steel W18Cr4V is used as the tool base material;

[0062] At a temperature of 25°C, the surface of the tool substrate was cleaned four times with a 9% sodium carbonate solution to remove surface grease.

[0063] After rinsing with clean water for 4 times, the surface of the tool substrate was cleaned with a hydrochloric acid solution with a mass fraction of 0.4% for 4 times to remove the surface rust, and then rinsed with clean water for 2 times to remove the residual hydrochloric acid solution to complete the surface purification of the tool substrate;

[0064] Then, the cleaned tool substrate is sandblasted to adjust the roughness Ra of the tool surface to 2.6 mm to complete the roughening treatment of the tool substrate;

[0065] Then, the roughened tool substrate is preheated to 410° C. in a nitrogen atmosphere and kept warm to complete the preheating of the tool, thereby obtaining a pretreated tool;

[0066] Surface spraying:

[0067] After the spraying material is heated to a molten state, plasma thermal spraying is performed on the surface of the pretreated tool under argon protection, and the coating thickness is controlled to be 0.66 mm. Then, the coating is cooled to room temperature to obtain a sprayed tool.

[0068] Among them, the plasma thermal spraying power is 32kW, the spraying distance is 110mm, the spraying angle is 72°, and the single spraying thickness is 0.01mm;

[0069] The spraying material includes metal alloy, non-metal material and nano manganese dioxide;

[0070] The mass ratio of the metal alloy and the non-metallic material is 58:1;

[0071] The metal alloy includes Al, Co, Cr, Fe, Ni and La;

[0072] Among them, the molar ratio of Al:Co:Cr:Fe:Ni:La is 1:1:1:1:1:0.06;

[0073] The non-metallic material is nano-silicon dioxide; the D50 of the nano-silicon dioxide is 85nm; and the particle size distribution range of the nano-silicon dioxide is 30-150nm;

[0074] The mass of the nano manganese dioxide is 3.5% of the mass of the metal alloy; the D50 of the nano manganese dioxide is 22nm;

[0075] Post-processing:

[0076] The sprayed tool was heated to 490°C at a rate of 5°C / min under inert atmosphere, heat treated for 100 min, cooled to room temperature, and then ground and polished to obtain a high entropy substrate nano-coated tool.

[0077] Example 3

[0078] Surface treatment of tool substrate:

[0079] The general high-speed steel W18Cr4V is used as the tool base material;

[0080] At a temperature of 25°C, the surface of the tool substrate was cleaned five times with a 10% sodium carbonate solution to remove surface grease.

[0081] After rinsing with clean water for 5 times, the surface of the tool substrate was cleaned with a hydrochloric acid solution with a mass fraction of 0.5% for 5 times to remove the surface rust, and then rinsed with clean water for 2 times to remove the residual hydrochloric acid solution to complete the surface purification of the tool substrate;

[0082] Then, the cleaned tool substrate is sandblasted to adjust the roughness Ra of the tool surface to 2.8 mm to complete the roughening treatment of the tool substrate;

[0083] Then, the roughened tool substrate is preheated to 420° C. in a nitrogen atmosphere and kept warm to complete the preheating of the tool, thereby obtaining a pretreated tool;

[0084] Surface spraying:

[0085] After the spraying material is heated to a molten state, plasma thermal spraying is performed on the surface of the pretreated tool under argon protection, and the coating thickness is controlled to be 0.68 mm. Then, the coating is cooled to room temperature to obtain a sprayed tool.

[0086] Among them, the plasma thermal spraying power is 35kW, the spraying distance is 120mm, the spraying angle is 75°, and the single spraying thickness is 0.01mm;

[0087] The spraying material includes metal alloy, non-metal material and nano manganese dioxide;

[0088] The mass ratio of the metal alloy and the non-metallic material is 60:1;

[0089] The metal alloy includes Al, Co, Cr, Fe, Ni and La;

[0090] Among them, the molar ratio of Al:Co:Cr:Fe:Ni:La is 1:1:1:1:1:0.06;

[0091] The non-metallic material is nano-silicon dioxide; the D50 of the nano-silicon dioxide is 90nm; and the particle size distribution range of the nano-silicon dioxide is 30-150nm;

[0092] The mass of the nano manganese dioxide is 5% of the mass of the metal alloy; the D50 of the nano manganese dioxide is 25 nm;

[0093] Post-processing:

[0094] The sprayed tool was heated to 500°C at a rate of 6°C / min under inert atmosphere, heat treated for 120 min, cooled to room temperature, and then ground and polished to obtain a high entropy substrate nano-coated tool.

[0095] Example 4

[0096] Compared with Example 1, this embodiment is different in that:

[0097] No nano manganese dioxide was added, and the other conditions remained unchanged.

[0098] Example 5

[0099] Compared with Example 1, this embodiment is different in that:

[0100] The mass of nano manganese dioxide is 6.2% of the mass of the metal alloy, and the other conditions remain unchanged.

[0101] Example 6

[0102] Compared with Example 1, this embodiment is different in that:

[0103] The mass of nano manganese dioxide is 1.7% of the mass of the metal alloy, and the other conditions remain unchanged.

[0104] Example 7

[0105] Compared with Example 1, this embodiment is different in that:

[0106] The D50 of nano-manganese dioxide is 85nm, and the other conditions remain unchanged.

[0107] Comparative Example 1

[0108] The difference between this comparative example and Example 1 is that La is not added, and the other conditions remain unchanged.

[0109] Comparative Example 2

[0110] The difference between this comparative example and Example 1 is that no nano silicon dioxide is added, and the other conditions remain unchanged.

[0111] The performance tests were performed on the products obtained in the above examples and comparative examples. The specific test methods and test results are as follows:

[0112] Prepare samples: Make sure the coating surface is clean and free of oil and dirt, and the coating should be uniform without obvious defects;

[0113] Select scratch tool: Use a stylus with a smooth conical tip (diamond indenter) for testing;

[0114] Set up the scratch tester: Adjust the scratch tester and set the scratch speed and loading rate. The scratch speed is set at 6mm / min.

[0115] Perform a scratch test: Using a scratch tester, gradually increase the load on the scratching needle while moving the sample so that the scratching needle scratches across the coating surface.

[0116] Monitoring the scratching process: The scratching process is monitored by acoustic emission detection technology or tangential force detection technology. When the coating is damaged, an acoustic signal is emitted or the tangential force changes.

[0117] Record critical load: The load applied when the coating fails is called critical load, which is a measure of the adhesion strength between the coating and the substrate. The detailed test results are shown in Table 1;

[0118] Table 1: Product performance test results

[0119] Critical load / N Example 1 89.5 Example 2 91.2 Example 3 90.8 Example 4 82.1 Example 5 85.5 Example 6 84.9 Example 7 86.3 Comparative Example 1 78.2 Comparative Example 2 77.9

[0120] It can be seen from the test results in Table 1 that the coating of the product obtained by the present invention has high adhesion and can maintain stable performance under a large load.

[0121] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing a high entropy substrate nano-coated tool, characterized in that: The specific preparation steps include: Surface treatment of tool substrate: Clean the surface of the tool to remove surface grease and rust; Then the tool surface is roughened; The tool is then preheated to obtain a pretreated tool; Surface spraying: After the spraying material is heated to a molten state, thermal spraying is performed on the surface of the pre-treated tool, and then cooled to room temperature to obtain a sprayed tool; The spraying material includes metal alloy and non-metallic material; The mass ratio of the metal alloy to the non-metallic material is (55-60):1; The metal alloy includes Al, Co, Cr, Fe, Ni and La; Among them, the molar ratio of Al:Co:Cr:Fe:Ni:La is 1:1:1:1:1:0.06; The non-metallic material is nano silicon dioxide; Post-processing: The sprayed tool is heat treated, cooled to room temperature, and then ground and polished to obtain a high entropy substrate nano-coated tool.

2. The method for preparing a high entropy substrate nano-coated tool according to claim 1, characterized in that: The surface cleaning comprises: Use 8-10% sodium carbonate solution to clean the tool surface 3-5 times to remove surface grease; After rinsing with clean water for 3-5 times, clean the tool surface for 3-5 times with a hydrochloric acid solution with a mass fraction of 0.3-0.5% to remove surface rust.

3. The method for preparing a high entropy substrate nano-coated tool according to claim 1, characterized in that: The roughening treatment comprises: The tool surface is sandblasted to adjust the tool surface roughness Ra to 2.5-2.8mm.

4. The method for preparing a high entropy substrate nano-coated tool according to claim 1, characterized in that: The preheating comprises: Preheat to 400-420℃ and keep warm.

5. The method for preparing a high entropy substrate nano-coated tool according to claim 1, characterized in that: The D50 of the nano-silicon dioxide is 80-90nm; and the particle size distribution range of the nano-silicon dioxide is 30-150nm.

6. The method for preparing a high entropy substrate nano-coated tool according to claim 1, characterized in that: The spraying material also includes nano manganese dioxide accounting for 2-5% of the mass of the metal alloy; the D50 of the nano manganese dioxide is 20-25nm.

7. The method for preparing a high entropy substrate nano-coated tool according to claim 1, characterized in that: The heat treatment comprises: Under inert atmosphere, heat to 480-500°C at a rate of 4-6°C / min and keep heat treatment for 80-120 minutes.

8. A high entropy substrate nano-coated tool, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 7.