High-entropy alloy, preparation method and application

Abstract

The invention discloses a high-entropy alloy, a preparation method and application, and the high-entropy alloy comprises the following components in parts by mass: 5-30 parts of Co; 5-30 parts by mass of Fe; 5-30 parts by mass of Ni; 1-10 parts by mass of B; 5-30 parts by mass of Si and 5-30 parts by mass of Cu; and 1-12 parts by mass of Nb. The high-entropy alloy provided by the invention has relatively high hardness and good wear resistance, has a good application prospect in crusher cutters, and is beneficial to prolonging the service life of the cutters.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and more specifically, to high-entropy alloys, preparation methods, and applications. Background Art

[0002] A crusher is an important device in a waste recycling production line. In industrial production, the consumption of crusher blades is relatively large. The forms of scrapping mainly involve wear and fracture. The service life depends not only on the material and processing quality of the blades themselves, but also on external material conditions, stress states, and other factors. The blades need to maintain a sharp edge while having a certain degree of toughness and wear resistance. The preparation of crusher blades mostly uses high-quality steel, and heat treatment methods are used to improve the microstructure of the steel, thereby enhancing the toughness, hardness, and wear resistance of the tool. However, most of these steels use expensive die steel and high-speed steel, which also increases the material cost pressure to a certain extent.

[0003] In view of this, a material that can improve the service life of crusher tools is particularly necessary. Summary of the Invention

[0004] The purpose of the present invention is to provide high-entropy alloys, preparation methods, and applications, to overcome the problem that the hardness and wear resistance of existing steels do not meet the requirements, and the service life as crusher tools is relatively short.

[0005] The present invention is implemented as follows:

[0006] In a first aspect, the present invention provides a high-entropy alloy, which includes, by mass parts:

[0007] 5 - 30 mass parts of Co;

[0008] 5 - 30 mass parts of Fe;

[0009] 5 - 30 mass parts of Ni;

[0010] 1 - 10 mass parts of B;

[0011] 5 - 30 mass parts of Si;

[0012] 5 - 30 mass parts of Cu;

[0013] 1 - 12 mass parts of Nb.

[0014] In an alternative embodiment, the molar ratio of Co, Fe, Ni, B, Si, and Cu in the high-entropy alloy is 1:(0.9 - 1.1):(0.9 - 1.1):(0.9 - 1.1):(0.9 - 1.1):(0.45 - 0.55).

[0015] In an alternative embodiment, the molar fraction of Nb in the high-entropy alloy is 1.5% - 3%.

[0016] In a second aspect, the present invention provides a blade, comprising a substrate and a coating provided on the surface of the substrate, wherein the material of the coating is the high-entropy alloy according to any one of the foregoing embodiments.

[0017] In a third aspect, the present invention provides a method for preparing the high-entropy alloy according to any one of the foregoing embodiments, comprising: under a protective atmosphere, using a semiconductor laser to perform cladding on the raw material powder of the high-entropy alloy laid on a substrate to form a coating of the high-entropy alloy on the substrate.

[0018] In an optional embodiment, the laying thickness of the raw material powder is 0.9 mm - 1.1 mm.

[0019] In an optional embodiment, the substrate is a steel plate.

[0020] In an optional embodiment, in the cladding step, the laser power is 1400 W - 1600 W, the scanning speed is 2 mm / s - 4 mm / s, and the spot diameter is 3 mm - 5 mm.

[0021] In an optional embodiment, before the raw material powder is subjected to cladding, it is first subjected to ball milling and mixing, the ball milling time is 5 h - 7 h, the ball-to-material ratio is (9 - 11):1, and the ball milling rotation speed is 180 r / min - 220 r / min.

[0022] In an optional embodiment, before laying the raw material powder of the high-entropy alloy on the substrate, the substrate is first cleaned and polished.

[0023] The present invention has the following beneficial effects:

[0024] The high-entropy alloy provided by the present invention has relatively high hardness and good wear resistance, and has good application prospects in crusher tools, which is beneficial to improving the service life of the tools. Specific Embodiments

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can be obtained as conventional products through commercial purchase.

[0026] High-entropy alloys have excellent properties that cannot be compared with some traditional alloys, such as high hardness, corrosion and wear resistance, and good oxidation resistance and other comprehensive properties, and are expected to be used as the coating material for current crusher tools.

[0027] An embodiment of the present invention provides a high-entropy alloy, by mass, comprising:

[0028] 5 - 30 parts by mass of Co;

[0029] 5 - 30 parts by mass of Fe;

[0030] 5 - 30 parts by mass of Ni;

[0031] 1 - 10 parts by mass of B;

[0032] 5 - 30 parts by mass of Si;

[0033] 5 - 30 parts by mass of Cu;

[0034] 1 - 12 parts by mass of Nb.

[0035] The high - entropy alloy provided by the embodiment of the present invention, due to the addition of B and Si elements, promotes the formation of silicides and borides, resulting in lattice distortion. The doping of Nb element can enhance the glass - forming ability of the coating. Therefore, this high - entropy alloy has high hardness and good wear resistance, and has good application prospects in crusher tools.

[0036] In an alternative embodiment, the molar ratio of Co, Fe, Ni, B, Si, and Cu in the high - entropy alloy is 1:(0.9 - 1.1):(0.9 - 1.1):(0.9 - 1.1):(0.9 - 1.1):(0.45 - 0.55).

[0037] Optimizing the proportion of elements in the high - entropy alloy in this embodiment is beneficial to further improving the hardness and wear resistance of the high - entropy alloy.

[0038] In an alternative embodiment, the molar fraction of Nb in the high - entropy alloy is 1.5% - 3%.

[0039] Both the hardness and wear resistance of the high - entropy alloy first increase and then decrease with the increase of the doping amount of niobium element. Preferably, when the molar fraction of niobium in the high - entropy alloy is 1.5% - 2.5%, the hardness and wear resistance of the high - entropy alloy are better.

[0040] The embodiment of the present invention also provides a blade, including a substrate and a coating provided on the surface of the substrate, and the material of the coating is the high - entropy alloy described in any one of the foregoing embodiments.

[0041] Setting a high - entropy alloy coating on the blade is beneficial to improving the service life of the blade while the cost price of the blade is low.

[0042] The embodiment of the present invention also provides a preparation method of the high - entropy alloy described in any one of the foregoing embodiments, including: under a protective atmosphere, using a semiconductor laser to perform cladding on the raw material powder of the high - entropy alloy laid on the substrate to form the coating of the high - entropy alloy on the substrate.

[0043] Laser cladding has an extremely high energy density and an extremely fast solidification rate, which can avoid element segregation and increase the solubility limit. The prepared coating has the advantages of fine microstructure, low dilution rate, small heat affected zone, and high bonding strength with the substrate.

[0044] In an alternative embodiment, the laying thickness of the raw material powder is 0.9 mm - 1.1 mm, and the thickness of the high-entropy alloy coating obtained after cladding is approximately 0.2 - 1.0 mm.

[0045] In an alternative embodiment, the substrate is a steel plate. For example, 45 steel plate can be selected, and the size can be 100 mm × 50 mm × 5 mm, or determined according to the model of the crusher.

[0046] In an alternative embodiment, in the cladding step, the laser power is 1400 W - 1600 W, the scanning speed is 2 mm / s - 4 mm / s, and the spot diameter is 3 mm - 5 mm.

[0047] In an alternative embodiment, before the raw material powder is cladded, it is first ball-milled and mixed. The ball-milling time is 5 h - 7 h, the ball-to-material ratio is (9 - 11):1, and the ball-milling rotation speed is 180 r / min - 220 r / min.

[0048] In an alternative embodiment, before laying the raw material powder of the high-entropy alloy on the substrate, the substrate is first cleaned and polished.

[0049] Specifically, in some embodiments, the substrate is first polished with 80-mesh sandpaper to ensure that the surface is clean and free of impurities, then cleaned with absolute ethanol, and then placed aside for use.

[0050] In the high-entropy alloy coating prepared in this application, the addition of B and Si elements can promote the formation of silicides and borides, resulting in lattice distortion. The doping of Nb element can enhance the glass-forming ability of the coating. Therefore, this high-entropy alloy coating has the advantages of high hardness and good wear resistance; the laser cladding method is selected to prepare this high-entropy alloy coating, and the coating surface has high density, and the process is relatively mature and easy to realize industrial mass production. As the coating material of the crusher blade, it can effectively extend the service life of the blade.

[0051] The features and properties of the present invention will be further described in detail below in conjunction with embodiments.

[0052] Example 1

[0053] This example provides a preparation method of a CoFeNiBSiCu 0.5 (with the doped Nb content of 1.00%) high-entropy alloy coating, including the following steps:

[0054] ① Substrate cleaning: First, grind the 45 steel plate substrate with 80-mesh sandpaper to ensure that the surface is clean and free of impurities, then clean and dry it with anhydrous ethanol and set it aside for use;

[0055] ② Weigh each element: weigh the metal powder according to the required mass;

[0056] ③ Mixing: The powder is placed in a ball mill for uniform mixing to obtain raw material powder of high entropy alloy, wherein the ball milling time is 6 h, the ball-to-material ratio is 10:1, and the ball milling speed is 200 r / min;

[0057] ④ Preparation of high entropy alloy coating: The raw material powder of the high entropy alloy was pre-placed on a 45 base steel plate with a preset powder thickness of about 1.0 mm. The raw material powder was clad using a semiconductor laser. Argon was introduced as a protective gas during the cladding process with a protective gas flow rate of 15 L / min. The laser power used was 1500 W, the scanning speed was 3 mm / s, and the spot diameter was 5 mm. A high entropy alloy coating sample was prepared.

[0058] Comparative Example 1

[0059] The sample of this comparative example is 45 steel plate.

[0060] Example 2-6 and Comparative Example 2-4:

[0061] The preparation methods of a high entropy alloy coating provided by Example 2-7 and Comparative Example 2-3 are the same as Example 1 except for the different raw material powder compositions, wherein the raw material compositions are shown in Table 1.

[0062] Table 1

[0063]

[0064]

[0065] The performance of the samples obtained in the above embodiments and comparative examples was tested. The test method is as follows. The test results are shown in Table 2.

[0066] The high entropy alloy coating samples prepared in the above steps were cut and hot-mounted, and then polished with sandpaper (240#, 400#, 600#, 800#, 1000#) in sequence, and then polished, and then subjected to Vickers hardness and wear tests. In the Vickers hardness test, the loading load was 1.961N and the loading time was 15s.

[0067] The friction and wear test of the sample was carried out using a reciprocating friction and wear testing machine. The normal load was 20N, the friction rate was 2m / min, and the friction partner was Si 3 N 4 Ceramic ball, 5mm diameter.

[0068] Table 2

[0069]

[0070]

[0071] Comparing Comparative Example 1 with the Examples, it can be shown that the high-entropy alloy coating in the present invention can improve the hardness and wear resistance of the substrate. From the comparison of Comparative Examples 2-3 and Examples 1-3, it can be seen that with the increase of Nb element, the hardness and wear resistance of the high-entropy alloy first increase and then decrease. This is because the Nb element can improve the stability of the BCC phase and has a dispersion strengthening function. The appropriate addition of the Nb element is beneficial to the formation of the glass phase, improving the hardness and wear resistance within a certain range. Among them, when the Nb doping amount is 2 at%, the prepared high-entropy alloy has good hardness and wear resistance. From the comparison of Examples 1, 4, and 5, it can be seen that with the increase of the B element content, the hardness and wear resistance of the high-entropy alloy are both improved. This is because the appropriate addition of the B element has good deoxidation and slag removal functions, and has good wettability, and is easy to form hard borides, thereby improving the hardness and wear resistance. From the comparison of Examples 1, 6, and 7, it can be seen that the Si element can reduce the overheating sensitivity of the steel and improve the tempering stability of the steel. Appropriately increasing the Si element content is easy to promote the formation of silicides and can improve the properties such as the hardness and wear resistance of the high-entropy alloy. However, too high contents of boron and silicon elements will also lead to the coarsening of grain boundaries and the increase of grains, reducing the corrosion resistance of the high-entropy alloy. Therefore, the addition amounts of the B element and the Si element should not be too high.

[0072] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high entropy alloy, characterized in that: Calculated by mass, including: Co 5-30 parts by mass; Fe 5-30 parts by mass; Ni 5-30 parts by mass; B 1-10 parts by mass; Si 5-30 parts by mass; Cu 5-30 parts by mass; Nb 1-12 parts by mass.

2. The high entropy alloy according to claim 1, characterized in that The molar ratio of Co, Fe, Ni, B, Si and Cu in the high entropy alloy is 1:(0.9-1.1):(0.9-1.1):(0.9-1.1):(0.9-1.1):(0.45-0.55).

3. The high entropy alloy according to claim 1, characterized in that The molar fraction of Nb in the high entropy alloy is 1.5%-3%.

4. A blade, characterized in that: It comprises a substrate and a coating arranged on the surface of the substrate, wherein the material of the coating is the high entropy alloy described in any one of claims 1-3.

5. A method for preparing a high entropy alloy according to any one of claims 1 to 3, characterized in that: include: Under a protective atmosphere, a semiconductor laser is used to melt-clad raw material powder of a high entropy alloy laid on a substrate to form a coating of the high entropy alloy on the substrate.

6. The method for preparing a high entropy alloy according to claim 5, characterized in that: The laying thickness of the raw material powder is 0.9 mm-1.1 mm.

7. The method for preparing a high entropy alloy according to claim 5, characterized in that: The substrate is a steel plate.

8. The method for preparing a high entropy alloy according to claim 5, characterized in that: In the cladding step, the laser power is 1400W-1600W, the scanning speed is 2mm / s-4mm / s, and the spot diameter is 3mm-5mm.

9. The method for preparing a high entropy alloy according to claim 5, characterized in that: The raw material powder is firstly ball-milled and mixed before cladding, the ball-milling time is 5h-7h, the ball-to-material ratio is (9-11):1, and the ball-milling speed is 180r / min-220r / min.

10. The method for preparing a high entropy alloy according to claim 5, characterized in that: The substrate is cleaned and polished before laying the raw material powder of the high entropy alloy.

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