A method for preparing a high-entropy alloy composite material

Abstract

The application provides a method for preparing a high-entropy alloy composite material. In the application, a high-entropy alloy grid is prepared by using a synchronous laser cladding technology, the high-entropy alloy grid is strengthened by using a heat treatment technology, the high-entropy alloy composite powder is formed by using a hot pressing technology, and finally the hot-pressed composite material is finally formed by using a laser melting technology. The existence of the high-entropy alloy grid can avoid the large-area enrichment of ceramic particles, the preform is prepared by using the hot pressing technology, the combination between the high-entropy alloy grid and the high-entropy alloy composite material in the subsequent melting process is increased, and the aggregation speed of the ceramic particles in the melting process is slowed down, so that the high-entropy alloy composite material is solidified and formed before the ceramic particles are aggregated. Therefore, the high-entropy alloy composite material prepared by the application does not have the aggregation of the reinforcing phase, and the composite material has good strength and toughness.

Description

Technical Field

[0001] This invention belongs to the field of metal material processing technology and relates to a method for preparing high-entropy alloy composite materials. Background Technology

[0002] High-entropy alloys, also known as multi-principal element alloys, are typically composed of five or more principal elements. Due to the high-entropy effect, high-entropy alloys tend to form simple solid solutions such as FCC and BCC, rather than intermetallic compounds. Therefore, high-entropy alloys exhibit unique microstructures and excellent properties, attracting widespread attention from researchers. However, high-entropy alloys have relatively low strength, especially those with FCC structures, which are difficult to meet the strength requirements for practical engineering applications. Ceramic reinforcing phases are strengthening phases that combine low density, high elastic modulus, high hardness, and excellent wear resistance. Introducing ceramic reinforcing phases into high-entropy alloys is one of the most effective ways to improve their strength. Currently, laser cladding is mainly used to prepare ceramic-reinforced high-entropy alloy composites, but ceramic reinforcing phases are prone to agglomeration, weakening their reinforcing effect. Therefore, exploring a method for preparing ceramic-reinforced high-entropy alloy composites has significant research and application value. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for preparing high-entropy alloy composite materials. In this invention, a high-entropy alloy mesh is first prepared using synchronous laser cladding technology, then strengthened using heat treatment technology, followed by hot pressing to form the high-entropy alloy composite powder, and finally, laser melting and solidification technology to finalize the hot-pressed composite material. Because the presence of the high-entropy alloy mesh prevents large-area enrichment of ceramic particles, the pre-preparation of the blank using hot pressing technology increases the bonding between the high-entropy alloy mesh and the high-entropy alloy composite material during subsequent melting and solidification, and slows down the aggregation rate of ceramic particles, thus solidifying before ceramic particles aggregate. Therefore, the high-entropy alloy composite material prepared by this invention does not experience the aggregation of reinforcing phases, and the composite material exhibits excellent strength and toughness properties.

[0004] This invention first provides a method for preparing high-entropy alloy composite materials, wherein no reinforcing phase aggregation occurs in the high-entropy alloy composite materials, and the high-entropy alloy composite materials have a tensile strength of 850-1080 MPa and an elongation of 13.8%-15.3% at room temperature.

[0005] Furthermore, the high-entropy alloy composite material is a TiC particle-reinforced FeCoNiCrMn-based high-entropy alloy.

[0006] This invention provides a method for producing high-entropy alloy composite materials, specifically including the following steps:

[0007] (1) Vacuum atomized high-entropy alloy powder is selected, and high-entropy alloy mesh is prepared by synchronous laser cladding technology. The horizontal and vertical spacing of the mesh is the same. The process parameters of the laser cladding are as follows: laser power is 1200-2000W, spot diameter is 2-6mm, scanning speed is 5-10mm / s, overlap rate is 40-60%, and powder feeding speed is 6-14g / min.

[0008] (2) Heat-treat the high-entropy alloy mesh obtained in step (1) at a temperature of 600-800℃ for 2-3 hours.

[0009] (3) The vacuum-atomized high-entropy alloy powder and ceramic particles are ball-milled and mixed, with a mass ratio of high-entropy alloy powder to ceramic particles of 100:5 to 10, to obtain a uniform composite powder.

[0010] (4) Place the high-entropy alloy mesh obtained in step (2) into a hot press mold, then heat and keep it warm, then pour the composite powder obtained in step (3) into the hot press mold, and use a press to perform hot pressing sintering. The hot pressing sintering temperature is 500-800℃ and the time is 60-80min. Finally, use an ejector to eject the prepared hot press blank.

[0011] (5) The hot-pressed blank obtained in step (4) is placed on the processing platform and the hot-pressed blank is melted and solidified using ultrasonic-assisted laser melting and solidification technology to obtain a high-entropy alloy composite material reinforced with ceramic particles. The process parameters of the laser melting and solidification are as follows: laser power 800-1000W, spot diameter 3-5mm, scanning speed 5-8mm / s, and overlap rate 40-50%.

[0012] (6) Repeat steps (1) to (5) on the surface of the high-entropy alloy composite material obtained in step (5) to obtain high-entropy alloy composite materials reinforced with ceramic particles of different thicknesses.

[0013] Furthermore, in step (1), the size of the high-entropy alloy powder is 15–53 μm.

[0014] Furthermore, in step (1), the spacing between the horizontal bars and the vertical bars of the high-entropy alloy mesh is 2 mm, and the thickness is 1 mm.

[0015] Furthermore, in step (2), the cooling method after heat treatment is water cooling.

[0016] Furthermore, in step (3), the size of the high-entropy alloy powder is 15–53 μm, and the size of the ceramic particles is 0.5–2 μm.

[0017] Furthermore, in step (4), the pressure of hot pressing sintering is 100-500 MPa.

[0018] Furthermore, in step (5), the ultrasonic-assisted process parameters are as follows: ultrasonic vibration frequency is 10-40KHz, and ultrasonic vibration power is 1000-5000W.

[0019] Furthermore, in step (6), the number of repetitions is 2 to 8 times.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The ceramic reinforcing phase in the high-entropy alloy composite material prepared by this invention did not undergo significant agglomeration. The prepared high-entropy alloy composite material has a tensile strength of 850–1080 MPa and an elongation of 13.8%–15.3% at room temperature, and can be well used under actual working conditions.

[0022] Currently, laser cladding is the main method used to prepare ceramic-reinforced high-entropy alloy composites. However, the ceramic reinforcing phase is prone to agglomeration, weakening its strengthening effect. This invention provides a method for preparing high-entropy alloy composites. In this invention, a high-entropy alloy mesh is first prepared using synchronous laser cladding technology, then the high-entropy alloy mesh is strengthened using heat treatment technology, followed by hot pressing technology to form the high-entropy alloy composite powder, and finally, laser melting and solidification technology is used to finalize the hot-pressed composite material. Because the presence of the high-entropy alloy mesh avoids large-area enrichment of ceramic particles, the pre-preparation of the blank using hot pressing technology increases the bonding between the high-entropy alloy mesh and the high-entropy alloy composite material during the subsequent melting and solidification process, and slows down the aggregation rate of ceramic particles, thus solidifying before the ceramic particles agglomerate. Therefore, the high-entropy alloy composite material prepared by this invention does not experience reinforcing phase agglomeration, and the composite material exhibits excellent strength and toughness. Attached Figure Description

[0023] Figure 1 The image shows the microstructure of the high-entropy alloy composite material prepared in Example 1 of this invention. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0025] Example 1:

[0026] (1) Vacuum atomized high-entropy alloy powder is selected. The size of the high-entropy alloy powder is 15-53μm. High-entropy alloy mesh is prepared by synchronous laser cladding technology. The horizontal and vertical spacing of the mesh is the same. The distance between the horizontal strips and the vertical strips of the high-entropy alloy mesh is 2mm. The thickness is 1mm. The laser cladding process parameters are as follows: laser power is 1600W, spot diameter is 4mm, scanning speed is 8mm / s, overlap rate is 50%, and powder feeding speed is 10g / min.

[0027] (2) The high-entropy alloy mesh obtained in step (1) is heat-treated at a temperature of 700℃ for 2 hours and cooled by water.

[0028] (3) The vacuum-atomized high-entropy alloy powder and ceramic particles are ball-milled and mixed. The mass ratio of high-entropy alloy powder to ceramic particles is 100:8. The size of the high-entropy alloy powder is 15-53 μm and the size of the ceramic particles is 0.5-2 μm, so as to obtain a uniform composite powder.

[0029] (4) Place the high entropy alloy mesh obtained in step (2) into a hot press mold, then heat and keep it warm, then pour the composite powder obtained in step (3) into the hot press mold, and use a press to perform hot pressing sintering. The hot pressing sintering temperature is 800℃, the time is 80min, the pressure is 350MPa, and finally the hot press blank is ejected using an ejector device.

[0030] (5) Place the hot-pressed blank obtained in step (4) on the processing platform and use ultrasonic-assisted laser melting and solidification technology to melt and solidify the hot-pressed blank to obtain a ceramic particle-reinforced high-entropy alloy composite material. The laser power is 1000W, the spot diameter is 4mm, the scanning speed is 6mm / s, the overlap rate is 50%, the ultrasonic vibration frequency is 20KHz, and the ultrasonic vibration power is 3000W.

[0031] (6) Repeat steps (1) to (5) on the surface of the high-entropy alloy composite material obtained in step (5) for a total of 4 times to obtain a ceramic particle reinforced high-entropy alloy composite material.

[0032] The microstructure of the prepared high-entropy alloy composite material was characterized, and its room-temperature tensile mechanical properties were tested to meet national standards. For example... Figure 1 The ceramic reinforcing phase particles in the high-entropy alloy composite material are uniformly distributed, with a tensile strength of 1080 MPa and an elongation of 15.3%.

[0033] Example 2:

[0034] It is basically the same as Example 1, but with the following changes: the laser power in step (1) is 1200W.

[0035] The high-entropy alloy composite material was subjected to room temperature tensile mechanical property tests that met national standards. The tensile strength was 850 MPa and the elongation was 13.8%.

[0036] Example 3:

[0037] It is basically the same as Example 1, but with the following changes: the laser power in step (1) is 2000W.

[0038] The high-entropy alloy composite material was subjected to room temperature tensile mechanical property tests that met national standards. The tensile strength was 930 MPa and the elongation was 14.2%.

[0039] Example 4:

[0040] It is basically the same as Example 1, but with the following changes: the hot pressing sintering temperature in step (4) is 600°C and the time is 60 min.

[0041] The high-entropy alloy composite material was subjected to room temperature tensile mechanical property tests that meet national standards. The tensile strength was 880 MPa and the elongation was 14.0%.

[0042] Example 5:

[0043] It is basically the same as Example 1, but with the following changes: step (6) is repeated twice.

[0044] The high-entropy alloy composite material was subjected to room temperature tensile mechanical property tests that met national standards. The tensile strength was 950 MPa and the elongation was 14.6%.

[0045] Comparative Example 1:

[0046] (1) Vacuum atomized high-entropy alloy powder and ceramic particles are ball-milled and mixed. The mass ratio of high-entropy alloy powder to ceramic particles is 100:8. The size of high-entropy alloy powder is 15-53μm and the size of ceramic particles is 0.5-2μm to obtain uniform composite powder.

[0047] (2) Using the composite powder obtained in step (1), a high-entropy alloy composite material is prepared by synchronous laser cladding technology. The laser cladding process parameters are as follows: laser power is 1600W, spot diameter is 4mm, scanning speed is 8mm / s, overlap rate is 50%, powder feeding speed is 10g / min, and the high-entropy alloy composite material product is obtained.

[0048] The high-entropy alloy composite material was subjected to room temperature tensile mechanical property tests that met national standards. The tensile strength was 680 MPa and the elongation was 10.8%.

[0049] Comparative Example 2:

[0050] (1) Vacuum atomized high-entropy alloy powder and ceramic particles are ball-milled and mixed. The mass ratio of high-entropy alloy powder to ceramic particles is 100:8. The particle size of high-entropy alloy powder is 15-53μm and the size of ceramic particles is 0.5-2μm, so as to obtain uniform composite powder.

[0051] (2) Pour the high-entropy alloy composite powder obtained in step (1) into a hot press mold and use a press to perform hot pressing sintering. The hot pressing sintering temperature is 800℃, the time is 80min, and the pressure is 350MPa. Finally, use an ejector to eject the prepared hot press blank to obtain the finished high-entropy alloy composite material.

[0052] The high-entropy alloy composite material was subjected to room temperature tensile mechanical property tests that met national standards. The tensile strength was 640 MPa and the elongation was 11.2%.

[0053] The embodiments described above are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a high-entropy alloy composite material, characterized in that, Specifically, the steps include the following: (1) Vacuum atomized high-entropy alloy powder is selected, and high-entropy alloy mesh is prepared by synchronous laser cladding technology. The horizontal and vertical spacing of the mesh is the same. The process parameters of the laser cladding are as follows: laser power is 1200-2000W, spot diameter is 2-6mm, scanning speed is 5-10mm / s, overlap rate is 40-60%, and powder feeding speed is 6-14g / min. (2) Heat-treat the high-entropy alloy mesh obtained in step (1) at a temperature of 600-800℃ for 2-3 hours. (3) The vacuum-atomized high-entropy alloy powder and ceramic particles are ball-milled and mixed, with a mass ratio of high-entropy alloy powder to ceramic particles of 100:5 to 10, to obtain a uniform composite powder. (4) Place the high-entropy alloy mesh obtained in step (2) into a hot press mold, then heat and keep it warm, then pour the composite powder obtained in step (3) into the hot press mold, and use a press to perform hot pressing sintering. The hot pressing sintering temperature is 500-800℃ and the time is 60-80min. Finally, use an ejector to eject the prepared hot press blank. (5) The hot-pressed blank obtained in step (4) is placed on the processing platform and the hot-pressed blank is melted and solidified using ultrasonic-assisted laser melting and solidification technology to obtain a high-entropy alloy composite material reinforced with ceramic particles. The process parameters of the laser melting and solidification are as follows: laser power 800-1000W, spot diameter 3-5mm, scanning speed 5-8mm / s, and overlap rate 40-50%. (6) Repeat steps (1) to (5) on the surface of the high-entropy alloy composite material obtained in step (5) to obtain high-entropy alloy composite materials reinforced with ceramic particles of different thicknesses.

2. The method for preparing a high-entropy alloy composite material according to claim 1, characterized in that, In step (1), the size of the high-entropy alloy powder is 15–53 μm.

3. The method for preparing a high-entropy alloy composite material according to claim 1, characterized in that, In step (1), the spacing between the horizontal bars and the vertical bars of the high-entropy alloy mesh is 2 mm, and the thickness is 1 mm.

4. The method for preparing a high-entropy alloy composite material according to claim 1, characterized in that, In step (2), the cooling method after heat treatment is water cooling.

5. The method for preparing a high-entropy alloy composite material according to claim 1, characterized in that, In step (3), the size of the high-entropy alloy powder is 15-53 μm, and the size of the ceramic particles is 0.5-2 μm.

6. The method for preparing a high-entropy alloy composite material according to claim 1, characterized in that, In step (4), the pressure of hot pressing sintering is 100-500 MPa.

7. The method for preparing a high-entropy alloy composite material according to claim 1, characterized in that, In step (5), the ultrasonic-assisted process parameters are as follows: ultrasonic vibration frequency is 10-40KHz, and ultrasonic vibration power is 1000-5000W.

8. The method for preparing a high-entropy alloy composite material according to claim 1, characterized in that, In step (6), the number of repetitions is 2 to 8.

9. A high-entropy alloy composite material prepared according to any one of claims 1 to 8, characterized in that, The high-entropy alloy composite material has a tensile strength of 850–1080 MPa and an elongation of 13.8%–15.3% at room temperature.

10. The high-entropy alloy composite material according to claim 9, characterized in that, The high-entropy alloy is a FeCoNiCrMn series high-entropy alloy.

11. The high-entropy alloy composite material according to claim 9, characterized in that, The high-entropy alloy composite material is a TiC particle-reinforced FeCoNiCrMn-based high-entropy alloy composite material.

Images