1. A preparation method of a high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material is characterized by comprising the following steps:

1) preparing composite powder: respectively ball-milling spherical Cu powder and CrCoNi powder into sheets, mixing by a wet milling process, and obtaining a composite powder green body by a vacuum filtration mode;

2) sintering of composite powder: sintering and molding the composite powder green body by adopting a spark plasma sintering process;

3) hot rolling and forming the composite material: and carrying out post plastic deformation on the sintered composite material by adopting a hot rolling process, thereby preparing the high-density medium-entropy CrCoNi alloy reinforced Cu-based laminated composite material.

2. The preparation method of the high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material as claimed in claim 1, is characterized in that: in the step 1), the volume percentage content of the CrCoNi powder and the Cu powder is as follows: 80-95 vol% of Cu powder and 5-20 vol% of CrCoNi powder.

3. The preparation method of the high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material as claimed in claim 1, is characterized in that: the technological parameters of the powder ball milling in the step 1) are as follows: the rotating speed of the ball mill is 300-500 r/min, the ball milling time is 4-8 h, and the ball-material ratio is 10: 1-20: 1.

4. The preparation method of the high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material as claimed in claim 1, is characterized in that: the parameters of the wet grinding process in the step 1) are as follows: the method is carried out by taking absolute ethyl alcohol as a ball milling medium, wherein the rotating speed of the ball mill is 300-400 r/min, the ball-material ratio is 3: 1-5: 1, and the ball milling time is 3-5 h.

5. The preparation method of the high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material as claimed in claim 1, is characterized in that: in the step 2), the sintering process parameters are as follows: the sintering temperature is 800-1000 ℃, the sintering pressure is 30-50 MPa, the sintering time is 20 min-1 h, and the sintering atmosphere is vacuum.

6. The preparation method of the high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material as claimed in claim 1, is characterized in that: in the step 3), the hot rolling forming process parameters are as follows: the hot rolling heat preservation temperature is 700-850 ℃, and the pressing amount is 30-50%.

7. A high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material is prepared by the method of any one of claims 1-6.

Background

Cu has excellent thermal and electrical conductivity and is widely used in the fields of electric power, electricity, weapons and the like. However, the strength of pure Cu is low, which limits the direct application of pure Cu in the industrial field. The addition of particle reinforcement to Cu matrices is a widely used approach to achieve mechanical properties that meet the needs of the application. Heretofore, various ceramic particles have been used as a reinforcing phase, such as Al₂O₃、SiC、TiB₂And the like. The strength and Young's modulus of the prepared Cu-based composite material can be obviously higher than that of pure Cu by adding ceramic particles into a Cu matrix, but the ductility and toughness of the Cu-based composite material are obviously reduced. This is mainly due to two aspects. On one hand, because the applied ceramic particles cannot be wetted by the Cu matrix, a metallurgical bonding interface cannot be formed between the ceramic particles and the Cu matrix, the bonding strength of the interface between the ceramic particles and the Cu matrix is low, and cracks are easy to nucleate and rapidly expand in an interface area in the bearing process of the composite material to cause premature fracture of the material. On the other hand, the hard and brittle ceramic particles have poor capability of coordinated deformation with the Cu matrix, and stress concentration easily occurs at the interface, resulting in interface cracking. Therefore, it is necessary to develop a completely new Cu-based composite material system, which overcomes the above-mentioned disadvantages of the existing ceramic particle reinforced Cu-based composite material, and makes the Cu-based composite material have both high strength and high ductility.

In recent years, high-entropy and medium-entropy alloys are widely concerned due to excellent strength, elongation and high wear resistance, but the preparation of Cu-based composite materials by using the medium-entropy alloy CrCoNi as a reinforcing phase is not reported. If CrCoNi with intrinsic excellent mechanical properties is used as a reinforcing phase, a metallurgical strong bonding interface can be formed through atomic interface diffusion, and the excellent coordinated deformability of the medium-entropy CrCoNi alloy can be exerted, so that the material is expected to obtain good toughness matching.

In addition, in recent years, the layered bionic material similar to the pearl draws great attention of scholars due to the unique structure and performance characteristics. Studies have shown that a laminate structure formed by alternating arrangements can result in higher strength and fracture toughness. In order to play the potential role of the high-entropy alloy in improving the mechanical property of the composite material and simultaneously further obviously improve the strength and toughness matching degree of the composite material, the design of the medium-entropy CrCoNi alloy reinforced Cu-based composite material into a layered structure is a feasible scheme. However, the relation among the preparation method, the microstructure and the mechanical property of the prior medium-entropy CrCoNi alloy reinforced Cu-based laminated composite material is still blank in the industrial and academic circles.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention mainly aims to provide a preparation method of a high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material.

The invention also aims to provide the high-strength-and-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material obtained by the method

The purpose of the invention is realized by the following scheme:

a preparation method of a high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material comprises the following steps:

1) preparing composite powder: respectively ball-milling spherical Cu powder and CrCoNi powder into sheets, mixing by a wet milling process, and obtaining a composite powder green body by a vacuum filtration mode;

2) sintering of composite powder: sintering and molding the composite powder green body by adopting a spark plasma sintering process;

3) hot rolling and forming the composite material: and carrying out post plastic deformation on the sintered composite material by adopting a hot rolling process, thereby preparing the high-density medium-entropy CrCoNi alloy reinforced Cu-based laminated composite material.

In the step 1), the volume percentage content of the CrCoNi powder and the Cu powder is as follows: 80-95 vol% of Cu powder and 5-20 vol% of CrCoNi powder;

the technological parameters of the powder ball milling in the step 1) are as follows: the rotating speed of the ball mill is 300-500 r/min, the ball milling time is 4-8 h, and the ball-material ratio is 10: 1-20: 1; the ball milling is preferably carried out under an argon atmosphere.

The parameters of the wet grinding process in the step 1) are as follows: the method is carried out by taking absolute ethyl alcohol as a ball milling medium, wherein the rotating speed of the ball mill is 300-400 r/min, the ball-material ratio is 3: 1-5: 1, and the ball milling time is 3-5 h.

In the step 2), the sintering process parameters are as follows: the sintering temperature is 800-1000 ℃, the sintering pressure is 30-50 MPa, the sintering time is 20 min-1 h, and the sintering atmosphere is vacuum.

In the step 3), the hot rolling forming process parameters are as follows: the hot rolling heat preservation temperature is 700-850 ℃, and the pressing amount is 30-50%.

The high-toughness medium-entropy CrCoNi particle reinforced Cu-based composite material is prepared by the method.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1) the adopted CrCoNi medium entropy alloy particles have high toughness and strong coordinated deformability, and are easy to form a diffusion metallurgical bonding interface with a Cu matrix.

2) After the Cu powder and the CrCoNi intermediate entropy alloy are subjected to sheet treatment, the self-assembly of the layered composite material can be realized only by liquid phase mixing and subsequent vacuum filtration, and the equipment requirement is low.

3) The CrCoNi intermediate entropy alloy and the Cu matrix have good sintering performance, can realize high-efficiency sintering by adopting sintering modes such as spark plasma sintering, common hot pressing, hot isostatic pressing and the like, and has wide selectivity of sintering equipment.

4) Based on the synergistic effect of the intrinsic property and the layered structure of the entropy alloy in the CrCoNi, the composite material disclosed by the invention not only has the ductility and toughness equivalent to that of pure Cu, but also has the strength remarkably improved, and shows excellent strong ductility matching degree.

Drawings

Fig. 1 is a scanning electron microscope image of 5 vol.% CrCoNi reinforced Cu-based composite.

Fig. 2 is a scanning electron microscope image of 10 vol.% CrCoNi reinforced Cu-based composite.

FIG. 3 shows the element distribution characterization results of CrCoNi reinforced Cu-based composite material.

Fig. 4 is a graph comparing the mechanical properties of 5 vol.% CrCoNi reinforced Cu-based composites with pure Cu.

Fig. 5 is a graph comparing the mechanical properties of 10 vol.% CrCoNi reinforced Cu-based composites with pure Cu.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.

The reagents used in the examples are commercially available without specific reference.

Example 1

The preparation method is characterized in that the CrCoNi medium entropy alloy reinforced Cu-based laminated composite material is prepared from 95 vol.% of spherical pure Cu powder and 5 vol.% of spherical pure CrCoNi powder. Weighing raw material powder according to the powder raw material ratio, pre-grinding pure Cu powder into flaky Cu powder by argon protection at the rotating speed of 350 revolutions per minute, with the ball-milling time of 5 hours and with the ball-milling parameter of ball-material ratio of 15:1, and pre-grinding the CrCoNi powder into flaky CrCoNi powder at the rotating speed of 450 revolutions per minute and with the ball-milling parameter of ball-material ratio of 20:1 for 4 hours. On the basis, the flaky Cu powder and the flaky CrCoNi powder are mixed in an alcohol medium by ball milling, the mixing parameters are that the rotating speed of a ball mill is 300 r/min, the ball-to-material ratio is 5:1, and the ball milling time is 5 hours, and then the mixture is subjected to vacuum filtration at room temperature to form a green body. And sintering the green body in a discharge plasma sintering furnace at 950 ℃ for 30min, wherein the mechanical pressure applied during sintering is 30MPa, and the protective atmosphere is vacuum. And finally, carrying out heat preservation on the sintered composite material at 850 ℃ for 1h, and then carrying out hot rolling with the rolling reduction of 50% to obtain the CrCoNi intermediate entropy alloy reinforced Cu-based laminated composite material. The tensile strength of the prepared CrCoNi layered particle reinforced Cu-based composite material is 265MPa, and the elongation is 29%.

Fig. 1 is a scanning electron microscope picture of 5 vol.% CrCoNi reinforced Cu-based composite material, showing that the CrCoNi reinforcing phase particles are distributed in a layered manner. FIG. 3 is a representation result of element distribution of CrCoNi reinforced Cu-based composite material, which shows that the CrCoNi reinforcing phase and the Cu matrix form a diffusion bonding interface.

Example 2

The preparation method is characterized in that the CrCoNi medium entropy alloy reinforced Cu-based composite material is prepared by using 90 vol.% of spherical pure Cu powder and 10 vol.% of spherical pure CrCoNi powder as raw materials. Weighing raw material powder according to the powder raw material ratio, pre-grinding pure Cu powder into flaky Cu powder by argon protection at the rotating speed of 350 revolutions per minute, with the ball-milling time of 5 hours and with the ball-milling parameter of ball-material ratio of 15:1, and pre-grinding CrCoNi powder balls into flaky CrCoNi powder at the rotating speed of 450 revolutions per minute and with the ball-milling parameter of ball-material ratio of 20:1 for 4 hours. On the basis, the flaky Cu powder and the flaky CrCoNi powder are mixed in an alcohol medium by ball milling, the mixing parameters are that the rotating speed of a ball mill is 300 r/min, the ball-to-material ratio is 3:1, and the ball milling time is 5 hours, and then the mixture is subjected to vacuum filtration at room temperature to form a green body. And sintering the green body in a discharge plasma sintering furnace at 950 ℃ for 20min, wherein the mechanical pressure applied during sintering is 50MPa, and the protective atmosphere is vacuum. And finally, carrying out heat preservation on the sintered composite material at 750 ℃ for 1h, and then carrying out hot rolling, wherein the rolling reduction is 30%, so as to obtain the CrCoNi intermediate entropy alloy reinforced Cu-based laminated composite material. The tensile strength of the prepared CrCoNi layered particle reinforced Cu-based composite material is 331MPa, and the elongation is 29.2%.

Example 3

The preparation method is characterized in that the CrCoNi medium entropy alloy reinforced Cu-based laminated composite material is prepared from 90 vol.% of spherical pure Cu powder and 10 vol.% of spherical pure CrCoNi powder. Weighing raw material powder according to the powder raw material ratio, ball-milling pure Cu powder into flaky Cu powder by argon protection at the rotating speed of 350 revolutions per minute for 8 hours and at the ball-milling parameter of 10:1, and ball-milling the CrCoNi powder into flaky CrCoNi powder at the rotating speed of 500 revolutions per minute for 4 hours and at the ball-milling parameter of 10: 1. On the basis, the flaky Cu powder and the flaky CrCoNi powder are mixed in an alcohol medium by ball milling, the mixing parameters are that the rotating speed of a ball mill is 350 r/min, the ball-to-material ratio is 4:1, and the ball milling time is 4 hours, and then the mixture is subjected to vacuum filtration at room temperature to form a green body. And sintering the green body in a discharge plasma sintering furnace at 1000 ℃ for 20min, wherein the mechanical pressure applied during sintering is 30MPa, and the protective atmosphere is vacuum. And finally, carrying out heat preservation on the sintered composite material at 750 ℃ for 1h, and then carrying out hot rolling, wherein the rolling reduction is 30%, so as to obtain the CrCoNi intermediate entropy alloy reinforced Cu-based laminated composite material. The tensile strength of the prepared CrCoNi layered particle reinforced Cu-based composite material is 319MPa, and the elongation is 29.4%.

Fig. 2 is a scanning electron microscope picture of 10 vol.% CrCoNi reinforced Cu-based composite material prepared in this example, which shows that the CrCoNi reinforcing phase particles with higher content are all distributed in a layered manner. Fig. 5 is a graph comparing the mechanical properties of 10 vol.% CrCoNi reinforced Cu-based composites with pure Cu.

Example 4

The preparation method is characterized in that the CrCoNi medium entropy alloy reinforced Cu-based laminated composite material is prepared from 85 vol.% of spherical pure Cu powder and 15 vol.% of spherical pure CrCoNi powder. Weighing raw material powder according to the powder raw material ratio, pre-grinding pure Cu powder into flaky Cu powder by argon protection at a rotating speed of 400 revolutions per minute with ball milling time of 5 hours and a ball-to-material ratio of 15:1, and pre-grinding the CrCoNi powder into flaky CrCoNi powder at a rotating speed of 450 revolutions per minute with ball milling time of 8 hours and a ball-to-material ratio of 10: 1. On the basis, the flaky Cu powder and the flaky CrCoNi powder are mixed in an alcohol medium by ball milling, the mixing parameters are that the rotating speed of a ball mill is 300 r/min, the ball-to-material ratio is 5:1, and the ball milling time is 5 hours, and then the mixture is subjected to vacuum filtration at room temperature to form a green body. And sintering the green body in a discharge plasma sintering furnace at 800 ℃ for 1h, wherein the mechanical pressure applied during sintering is 50MPa, and the protective atmosphere is vacuum. And finally, carrying out heat preservation on the sintered composite material at 850 ℃ for 1h, and then carrying out hot rolling with the rolling reduction of 50% to obtain the CrCoNi intermediate entropy alloy reinforced Cu-based laminated composite material. The prepared CrCoNi layered particle reinforced Cu-based composite material has the tensile strength of 363MPa and the elongation of 17.5 percent.

Example 5

The preparation method is characterized in that the CrCoNi medium entropy alloy reinforced Cu-based laminated composite material is prepared from 85 vol.% of spherical pure Cu powder and 15 vol.% of spherical pure CrCoNi powder. Weighing raw material powder according to the powder raw material ratio, pre-grinding pure Cu powder into flaky Cu powder by argon protection at the rotating speed of 350 revolutions per minute, with the ball-milling time of 5 hours and with the ball-milling parameter of ball-to-material ratio of 15:1, and ball-milling the CrCoNi powder into flaky CrCoNi powder at the rotating speed of 450 revolutions per minute and with the ball-milling parameter of ball-to-material ratio of 20:1 for 4 hours. On the basis, the flaky Cu powder and the flaky CrCoNi powder are mixed in an alcohol medium by ball milling, the mixing parameters are that the rotating speed of a ball mill is 300 r/min, the ball-to-material ratio is 3:1, and the ball milling time is 5 hours, and then the mixture is subjected to vacuum filtration at room temperature to form a green body. And sintering the green body in a discharge plasma sintering furnace at 950 ℃ for 20min, wherein the mechanical pressure applied during sintering is 50MPa, and the protective atmosphere is vacuum. And finally, carrying out hot rolling on the sintered composite material after heat preservation for 1h at 850 ℃, wherein the rolling reduction is 30%, and obtaining the CrCoNi intermediate entropy alloy reinforced Cu-based laminated composite material. The tensile strength of the prepared CrCoNi layered particle reinforced Cu-based composite material is 372MPa, and the elongation is 17.9%.

Example 6

The preparation method is characterized in that the CrCoNi medium entropy alloy reinforced Cu-based laminated composite material is prepared from 80 vol.% of spherical pure Cu powder and 20 vol.% of spherical pure CrCoNi powder. Weighing raw material powder according to the powder raw material ratio, ball-milling pure Cu powder into flaky Cu powder by argon protection at the rotating speed of 350 revolutions per minute for 5 hours and at the ball-milling parameter of ball-to-material ratio of 15:1, and ball-milling the CrCoNi powder into flaky CrCoNi powder at the rotating speed of 450 revolutions per minute for 4 hours and at the ball-milling parameter of ball-to-material ratio of 20: 1. On the basis, the flaky Cu powder and the flaky CrCoNi powder are mixed in an alcohol medium by ball milling, the ball milling mixing parameters are that the rotating speed of a ball mill is 350 r/min, the ball-material ratio is 3:1, and the ball milling time is 5 hours, and then the mixture is subjected to vacuum filtration at room temperature to form a green body. And sintering the green body in a discharge plasma sintering furnace at 950 ℃ for 20min, wherein the mechanical pressure applied during sintering is 50MPa, and the protective atmosphere is vacuum. And finally, carrying out heat preservation on the sintered composite material at 800 ℃ for 1h, and then carrying out hot rolling, wherein the rolling reduction is 30%, so as to obtain the CrCoNi intermediate entropy alloy reinforced Cu-based laminated composite material. The prepared CrCoNi layered particle reinforced Cu-based composite material has the tensile strength of 395MPa and the elongation of 10.7 percent.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.