阅读说明：本技术 一种双元素等量变换的高熵合金烧结成型工艺 (High-entropy alloy sintering forming process with double-element equivalent transformation ) 是由 张云鹏 雷宇辉 杜长春 于 2021-08-12 设计创作，主要内容包括：本发明公开了一种双元素等量变换的高熵合金烧结成型工艺,具体按照如下步骤实施：步骤1,将Co、Cr、Fe、Ni、Cu、Ti单质粉末按照等原子百分比进行称量混合,将其配置成不同比例成分的CoCrFeNi(CuTi)-(x)高熵合金粉末,其中x＝0.2-1.0；步骤2,将步骤1配置的高熵合金粉末置于球磨罐中进行高能球磨,制备出所需成分均匀的不同比例成分的混合高熵合金粉末；步骤3,将步骤2得到的混合高熵合金粉末进行真空热压烧结或快速热压烧结成型,待其烧结冷却后脱模得到(CuTi)-(x)双元素等量变换的高熵合金块体。本发明制备方法简单、生产成本低且得到的高熵合金致密度高、组织均匀。(The invention discloses a high-entropy alloy sintering forming process with double-element equivalent transformation, which is implemented according to the following steps: step 1, weighing and mixing simple substance powders of Co, Cr, Fe, Ni, Cu and Ti according to equal atomic percentage, and preparing the simple substance powders into CoCrFeNi (CuTi) with different proportional components x High entropy alloy powder, wherein x is 0.2-1.0; step 2, placing the high-entropy alloy powder prepared in the step 1 into a ball milling tank for high-energy ball milling to prepare mixed high-entropy alloy powder with required components in uniform and different proportions; step 3, carrying out vacuum hot-pressing sintering or rapid hot-pressing sintering molding on the mixed high-entropy alloy powder obtained in the step 2, and demoulding after sintering and cooling to obtain (CuTi) x High-entropy alloy block with double-element equivalent transformation. The preparation method is simple, the production cost is low, and the obtained high-entropy alloyThe gold has high density and uniform tissue.)

1. A high-entropy alloy sintering forming process with double-element equivalent transformation is characterized by comprising the following steps:

step 1, weighing and mixing simple substance powders of Co, Cr, Fe, Ni, Cu and Ti according to equal atomic percentage, and preparing the simple substance powders into CoCrFeNi (CuTi) with different proportional components_xHigh entropy alloy powder, wherein x is 0.2-1.0;

step 2, placing the high-entropy alloy powder prepared in the step 1 into a ball milling tank for high-energy ball milling to prepare mixed high-entropy alloy powder with required components in uniform and different proportions;

step 3, carrying out vacuum hot-pressing sintering or rapid hot-pressing sintering molding on the mixed high-entropy alloy powder obtained in the step 2, and demoulding after sintering and cooling to obtain (CuTi)_xHigh-entropy alloy block with double-element equivalent transformation.

2. A high-entropy alloy sintering molding process with equivalent double-element transformation as claimed in claim 1, wherein the simple substance powder of Co, Cr, Fe, Ni, Cu and Ti in step 1 is powder with purity of 99% and particle size of 40-48 um.

3. A double-element equivalent transformation high-entropy alloy sintering forming process according to claim 1, wherein the mass ratio of balls to materials in ball milling in the step 2 is 8-12: 1, the rotating speed of the ball mill is 200-400 r/min, and the ball milling time is 20-24 h.

4. A double-element equivalent transformation high-entropy alloy sintering forming process according to claim 3, wherein the grinding balls in the ball milling in the step 2 are divided into three types, namely large, medium and small grinding balls with diameters of 9.5mm, 5mm and 3 mm; the mass ratio of the large grinding ball to the medium grinding ball to the small grinding ball is 2: 3: 5.

5. a double-element equivalent transformation high-entropy alloy sintering forming process according to claim 1, wherein the vacuum degree of vacuum hot-pressing sintering in the step 3 is 1.5x10^-2pa sintering pressureThe temperature is 30-40 MPa, the sintering temperature is 1050-1200 ℃, and the heat preservation time is 30-60 min.

6. A high-entropy alloy sintering molding process of double-element equivalent transformation according to claim 5, characterized in that the vacuum hot-pressing sintering specifically comprises:

pre-pressing the mixed high-entropy alloy powder obtained in the step 2 in a graphite grinding tool, then placing the graphite grinding tool in a sintering furnace to apply pressure to 30-40 Mpa, and then vacuumizing to the vacuum degree of 1.5x10^-2pa; heating from room temperature to 300 ℃ at a heating rate of 10 ℃/min, and keeping the temperature at 300 ℃ for 10 min; then heating up from 300 ℃ to 1050-1200 ℃ at the heating rate of 10 ℃/min, and preserving the heat for 30-60 min.

7. A sintering forming process for a high-entropy alloy with two elements being transformed in equal amount according to claim 1, wherein the vacuum degree of the rapid hot-pressing sintering in the step 3 is 1.2pa, the sintering pressure is 30-40 MPa, the sintering temperature is 950-1050 ℃, and the heat preservation time is 30-60 min.

8. A double-element equivalent transformation high-entropy alloy sintering forming process according to claim 7, wherein the rapid hot-pressing sintering in the step 3 is specifically as follows: prepressing the mixed high-entropy alloy powder obtained in the step 2 in a graphite grinding tool, and then placing the graphite grinding tool in a sintering furnace to apply pressure to 30-40 MPa; vacuumizing until the vacuum degree is 1.2 pa; heating from room temperature to 300 ℃ at a heating rate of 100 ℃/min, and keeping the temperature at 300 ℃ for 10 min; and then heating from 300 ℃ to 950-1050 ℃ at the heating rate of 100 ℃/min, and preserving the heat for 30-60 min.

Technical Field

The invention belongs to the technical field of high-entropy alloy preparation processes, and relates to a high-entropy alloy sintering forming process with double-element equivalent transformation.

Background

The high-entropy alloy is a novel alloy derived in the development process of amorphous alloy, and has excellent performances such as high hardness, high corrosion resistance, high wear resistance, high oxidation resistance and the like, so that the high-entropy alloy attracts the wide attention of material researchers. In 1995, professor yeasts a design concept of multi-principal element high-entropy alloy: the alloy elements are generally more than or equal to 5 elements, the atomic percent of each element is between 5 and 35 percent, and the entropy value is more than 1.61R. The design concept of the novel alloy breaks through the design concept of the traditional alloy with single principal element, and creates a new idea in the field of alloy design. The traditional alloy design concept considers that the more alloy components, the more intermetallic compounds or complex phases are easily formed. However, studies have shown that alloy compositions consisting of a plurality of main elements produce a high entropy effect which promotes the formation of a solid solution phase having a body-centered cubic phase or a face-centered cubic phase, suppresses the formation of intermetallic compounds, and can even favor the formation of an amorphous structure.

Hitherto, the preparation processes of high-entropy alloys can be mainly divided into four methods, namely a mechanical alloying method, a powder metallurgy method, a vacuum melting method and a laser cladding method, however, the methods such as the vacuum melting method and the laser cladding method are only suitable for laboratory research and have a series of defects of huge cost, complex equipment, complex process, inevitable tissue segregation and the like, so that the method has a large influence on future commercial development of the high-entropy alloys, limits the batch production of the high-entropy alloys and is not beneficial to the application of the high-entropy alloys. However, the mechanical alloying method is often combined with the powder metallurgy method, and the mechanical alloying method can effectively improve the structure segregation, has low production cost, can realize mass production and the like, so that the exploration of the sintering process of vacuum hot pressing and rapid hot pressing sintering is very important for the mass production of future high-entropy alloys.

Disclosure of Invention

The invention aims to provide a double-element equivalent transformation high-entropy alloy sintering forming process, which is simple in preparation method and low in production cost, and the obtained high-entropy alloy is high in density and uniform in structure.

The technical scheme adopted by the invention is that a double-element equivalent transformation high-entropy alloy sintering forming process is implemented according to the following steps:

step 1, performing elementary powder of Co, Cr, Fe, Ni, Cu and Ti according to equal atomic percentageWeighing and mixing the materials, and preparing the materials into CoCrFeNi (CuTi) with different proportional components_xHigh-entropy alloy mixed powder, wherein x is 0.2-1.0;

step 2, placing the high-entropy alloy mixed powder prepared in the step 1 into a ball milling tank for high-energy ball milling to prepare mixed high-entropy alloy powder with required components in uniform and different proportions;

step 3, carrying out vacuum hot-pressing sintering or rapid hot-pressing sintering molding on the mixed high-entropy alloy powder obtained in the step 2, and demoulding after sintering and cooling to obtain (CuTi)_xHigh-entropy alloy block with double-element equivalent transformation.

The present invention is also characterized in that,

the simple substance powder of Co, Cr, Fe, Ni, Cu and Ti in the step 1 is powder with the purity of 99 percent and the grain diameter of 40um-48 um.

In the step 2, the mass ratio of the ball materials during ball milling is 8-12: 1, the rotating speed of the ball mill is 200-400 r/min, and the ball milling time is 20-24 h.

In the step 2, the grinding balls are divided into large, medium and small grinding balls with the diameters of 9.5mm, 5mm and 3mm during ball milling; the mass ratio of the large, medium and small grinding balls is 2: 3: 5.

the vacuum degree of the vacuum hot-pressing sintering in the step 3 is 1.5x10^-2pa, sintering pressure is 30-40 MPa, sintering temperature is 1050-1200 ℃, and heat preservation time is 30-60 min.

The vacuum hot-pressing sintering comprises the following specific steps:

pre-pressing the mixed high-entropy alloy powder obtained in the step 2 in a graphite grinding tool, then placing the graphite grinding tool in a sintering furnace to apply pressure to 30-40 Mpa, and then vacuumizing to the vacuum degree of 1.5x10^-2pa; heating from room temperature to 300 ℃ at a heating rate of 10 ℃/min, and keeping the temperature at 300 ℃ for 10 min; then heating up from 300 ℃ to 1050-1200 ℃ at the heating rate of 10 ℃/min, and preserving the heat for 30-60 min.

The vacuum degree of the rapid hot-pressing sintering in the step 3 is 1.2pa, the sintering pressure is 30-40 MPa, the sintering temperature is 950-1050 ℃, and the heat preservation time is 30-60 min.

The rapid hot-pressing sintering in the step 3 comprises the following specific steps: prepressing the mixed high-entropy alloy powder obtained in the step 2 in a graphite grinding tool, and then placing the graphite grinding tool in a sintering furnace to apply pressure to 30-40 MPa; vacuumizing until the vacuum degree is 1.2 pa; heating from room temperature to 300 ℃ at a heating rate of 100 ℃/min, and keeping the temperature at 300 ℃ for 10 min; and then heating from 300 ℃ to 950-1050 ℃ at the heating rate of 100 ℃/min, and preserving the heat for 30-60 min.

The invention has the beneficial effects that:

the method can quickly prepare the required high-density high-entropy alloy block, has low preparation cost and simple equipment operation, and is suitable for industrial mass production.

The alloy block prepared by the method has uniform structure components and effectively avoids component segregation.

Drawings

Fig. 1 is a metallographic structure diagram and an SEM scan of a cocrfeni (cuti) X high-entropy alloy bulk material with X being 0.4 in example 3 of the present invention;

fig. 2 is a metallographic structure diagram and an SEM scan of a cocrfeni (cuti) X high-entropy alloy bulk material with X being 0.4 in example 5 of the present invention;

fig. 3 is a metallographic structure diagram and an SEM scan of a cocrfeni (cuti) X high-entropy alloy bulk material with X being 0.4 according to example 6 of the present invention;

FIG. 4 is a graph of the optimum sintering temperature versus time for vacuum hot pressing sintering in accordance with the present invention;

FIG. 5 is a graph of the optimum sintering temperature versus time for the rapid hot press sintering of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention relates to a high-entropy alloy sintering forming process with double-element equivalent transformation, which is implemented by the following steps:

step 1, weighing and mixing simple substance powder of Co, Cr, Fe, Ni, Cu and Ti with the purity of 99 percent and the grain diameter of 40um-48um according to equal atomic percentage, and preparing the powder into CoCrFeNi (CuTi) with different proportional components_xHigh entropy alloy powder, wherein x is 0.2-1.0;

step 2, placing the high-entropy alloy powder prepared in the step 1 into a ball milling tank for high-energy ball milling, wherein the mass ratio of ball materials during ball milling is 8-12: 1, the rotating speed of the ball mill is 200-400 r/min, the ball milling time is 20-24 h, and the grinding balls are divided into three types of large, medium and small grinding balls with the diameters of 9.5mm, 5mm and 3 mm; the mass ratio of the large, medium and small grinding balls is 2: 3: 5, preparing mixed high-entropy alloy powder with required components in uniform and different proportions;

step 3, carrying out vacuum hot-pressing sintering or rapid hot-pressing sintering molding on the mixed high-entropy alloy powder obtained in the step 2, and demoulding after sintering and cooling to obtain (CuTi)_xA high-entropy alloy block body with double-element equivalent transformation;

in the case of vacuum hot-pressing sintering, the degree of vacuum hot-pressing sintering is 1.5X10^-2pa, sintering pressure is 30-40 MPa, sintering temperature is 1050-1200 ℃, and heat preservation time is 30-60 min, specifically:

pre-pressing the mixed high-entropy alloy powder obtained in the step 2 in a graphite grinding tool, then placing the graphite grinding tool in a sintering furnace to apply pressure to 30-40 Mpa, and then vacuumizing to the vacuum degree of 1.5x10^-2pa; heating from room temperature to 300 ℃ at a heating rate of 10 ℃/min, and keeping the temperature at 300 ℃ for 10 min; then heating up from 300 ℃ to 1050-1200 ℃ at the heating rate of 10 ℃/min, and preserving the heat for 30-60 min.

If the rapid hot-pressing sintering is carried out, the vacuum degree of the rapid hot-pressing sintering is 1.2pa, the sintering pressure is 30-40 MPa, the sintering temperature is 950-1050 ℃, and the heat preservation time is 30-60 min, specifically: prepressing the mixed high-entropy alloy powder obtained in the step 2 in a graphite grinding tool, and then placing the graphite grinding tool in a sintering furnace to apply pressure to 30-40 MPa; vacuumizing until the vacuum degree is 1.2 pa; heating from room temperature to 300 ℃ at a heating rate of 100 ℃/min, and keeping the temperature at 300 ℃ for 10 min; and then heating from 300 ℃ to 950-1050 ℃ at the heating rate of 100 ℃/min, and preserving the heat for 30-60 min.

Example 1

CoCrFeNi (CuTi) with alloy component x being 0.4_xThe high-entropy alloy powder is subjected to a sintering comparison test.

Co powder, Cr powder, Fe powder, Ni powder, Cu powder and Ti powder with the purity of 99 percent and the grain diameter of 44um are adopted as raw materialsThe raw materials are weighed and mixed according to an equal atomic ratio to prepare high-entropy alloy mixed powder with the ratio of Co to Cr to Fe to Ni to Cu to Ti being 1:1:1:0.4:0.4, and then the high-entropy alloy mixed powder is subjected to ball milling in a ball mill for 20-24 hours. Putting the mixed powder into a mold, vibrating uniformly and pre-pressing, putting the mold into a furnace chamber of a vacuum hot-pressing sintering furnace for pressure sintering, wherein the pressure is maintained at 30-40 MPa in the sintering process, and vacuumizing until the vacuum degree is 1.5x10^-2pa, then heating from room temperature to 300 ℃ at the heating rate of 10 ℃/min, and keeping the temperature at 300 ℃ for 10 min; then heating from 300 ℃ to 1050 ℃ at the heating rate of 10 ℃/min, preserving the heat for 60min, and then cooling and releasing the pressure; the prepared blank is sequentially subjected to surface grinding and deburring treatment, and the prepared vacuum hot-pressing sintered CoCrFeNi (CuTi) with x being 0.4_xHigh entropy alloy block.

Wherein the addition amount of the process control agent in the ball milling process is 0.6-1.2%, and the mass ratio of the ball material is 8-12: 1, wherein the grinding balls are divided into three types of large, medium and small, and the diameters of the grinding balls are 9.5mm, 5mm and 3 mm; the mass ratio of the large, medium and small grinding balls is 2: 3: 5.

CoCrFeNi (CuTi) with x being 0.4_xAfter grinding and polishing the high-entropy alloy material sample, carrying out tissue and performance tests, wherein the obtained technical parameters are shown in table 1;

table 1 results of performance test of high entropy alloy material prepared in example 1

Example 2

CoCrFeNi (CuTi) with alloy component x being 0.4_xThe high-entropy alloy powder is subjected to a sintering comparison test.

Co powder, Cr powder, Fe powder, Ni powder, Cu powder and Ti powder with the purity of 99% and the particle size of 44um are used as raw materials, weighed and mixed according to equal atomic ratio to prepare high-entropy alloy mixed powder with the ratio of Co, Cr, Fe, Ni, Cu and Ti being 1:1:1:0.4:0.4, and then ball-milled in a ball mill for 20-24 hours. Putting the mixed powder into a mould, vibrating uniformly and prepressing, putting the mould into a furnace chamber of a vacuum hot-pressing sintering furnace for addingPressure sintering, wherein the pressure is maintained at 30-40 MPa in the sintering process, and the vacuum degree is 1.5x10^-2pa, then heating from room temperature to 300 ℃ at the heating rate of 10 ℃/min, and keeping the temperature at 300 ℃ for 10 min; then heating from 300 ℃ to 1100 ℃ at the heating rate of 10 ℃/min, preserving the heat for 60min, and then cooling and releasing the pressure; the prepared blank is sequentially subjected to surface grinding and deburring treatment, and the prepared vacuum hot-pressing sintered CoCrFeNi (CuTi) with x being 0.4_xHigh entropy alloy block.

Wherein the addition amount of the process control agent in the ball milling process is 0.6-1.2%, and the mass ratio of the ball material is 8-12: 1, wherein the grinding balls are divided into three types of large, medium and small, and the diameters of the grinding balls are 9.5mm, 5mm and 3 mm; the mass ratio of the large, medium and small grinding balls is 2: 3: 5.

CoCrFeNi (CuTi) with x being 0.4_xAfter grinding and polishing the high-entropy alloy material sample, carrying out tissue and performance tests, wherein the obtained technical parameters are shown in table 2;

table 2 results of performance test of the high-entropy alloy material prepared in example 1

Example 3

CoCrFeNi (CuTi) with alloy component x being 0.4_xThe high-entropy alloy powder is subjected to a sintering comparison test.

Co powder, Cr powder, Fe powder, Ni powder, Cu powder and Ti powder with the purity of 99% and the particle size of 44um are used as raw materials, weighed and mixed according to equal atomic ratio to prepare high-entropy alloy mixed powder with the ratio of Co, Cr, Fe, Ni, Cu and Ti being 1:1:1:0.4:0.4, and then ball-milled in a ball mill for 20-24 hours. Putting the mixed powder into a mold, vibrating uniformly and pre-pressing, putting the mold into a furnace chamber of a vacuum hot-pressing sintering furnace for pressure sintering, wherein the pressure is maintained at 30-40 MPa in the sintering process, and vacuumizing until the vacuum degree is 1.5x10^-2pa, then heating from room temperature to 300 ℃ at the heating rate of 10 ℃/min, and keeping the temperature at 300 ℃ for 10 min; then heating from 300 ℃ to 1150 ℃ at the heating rate of 10 ℃/min, preserving heat for 60min, and then cooling and releasing pressure; the prepared blanks are sequentially fed intoAnd carrying out surface grinding and deburring treatment to prepare a vacuum hot-pressed sintered CoCrFeNi (CuTi) x high-entropy alloy block with x being 0.4.

Wherein the addition amount of the process control agent in the ball milling process is 0.6-1.2%, and the mass ratio of the ball material is 8-12: 1, wherein the grinding balls are divided into three types of large, medium and small, and the diameters of the grinding balls are 9.5mm, 5mm and 3 mm; the mass ratio of the large, medium and small grinding balls is 2: 3: 5.

CoCrFeNi (CuTi) with x being 0.4_xAfter grinding and polishing the high-entropy alloy material sample, carrying out tissue and performance tests, wherein the obtained technical parameters are shown in a table 3;

table 3 results of performance test of the high-entropy alloy material prepared in example 1

Example 4

CoCrFeNi (CuTi) with alloy component x being 0.4_xThe high-entropy alloy powder is subjected to a sintering comparison test.

Co powder, Cr powder, Fe powder, Ni powder, Cu powder and Ti powder with the purity of 99% and the particle size of 44um are used as raw materials, weighed and mixed according to equal atomic ratio to prepare high-entropy alloy mixed powder with the ratio of Co, Cr, Fe, Ni, Cu and Ti being 1:1:1:0.4:0.4, and then ball-milled in a ball mill for 20-24 hours. Putting the mixed powder into a mold, vibrating uniformly and pre-pressing, putting the mold into a furnace chamber of a vacuum hot-pressing sintering furnace for pressure sintering, wherein the pressure is maintained at 30-40 MPa in the sintering process, and vacuumizing until the vacuum degree is 1.5x10^-2pa, then heating from room temperature to 300 ℃ at the heating rate of 10 ℃/min, and keeping the temperature at 300 ℃ for 10 min; then heating from 300 ℃ to 1200 ℃ at the heating rate of 10 ℃/min, preserving the heat for 60min, and then cooling and releasing the pressure; the prepared blank is sequentially subjected to surface grinding and deburring treatment, and the prepared vacuum hot-pressing sintered CoCrFeNi (CuTi) with x being 0.4_xHigh-entropy alloy blockAnd (3) a body.

Wherein the addition amount of the process control agent in the ball milling process is 0.6-1.2%, and the mass ratio of the ball material is 8-12: 1, wherein the grinding balls are divided into three types of large, medium and small, and the diameters of the grinding balls are 9.5mm, 5mm and 3 mm; the mass ratio of the large, medium and small grinding balls is 2: 3: 5.

CoCrFeNi (CuTi) with x being 0.4_xAfter grinding and polishing the high-entropy alloy material sample, carrying out tissue and performance tests, wherein the obtained technical parameters are described in table 4;

table 4 results of performance test of the high-entropy alloy material prepared in example 1

Example 5

CoCrFeNi (CuTi) with alloy component x being 0.4_xThe high-entropy alloy powder is subjected to a sintering comparison test.

Co powder, Cr powder, Fe powder, Ni powder, Cu powder and Ti powder with the purity of 99% and the particle size of 44um are used as raw materials, weighed and mixed according to equal atomic ratio to prepare high-entropy alloy mixed powder with the ratio of Co, Cr, Fe, Ni, Cu and Ti being 1:1:1:0.4:0.4, and then ball-milled in a ball mill for 20-24 hours. Putting the mixed powder into a mold, vibrating uniformly and prepressing, putting the mold into a furnace chamber of a rapid hot-pressing sintering furnace for pressure sintering, maintaining the pressure at 30-40 MPa in the sintering process, vacuumizing to the vacuum degree of 1.2pa, raising the temperature from room temperature to 300 ℃ at the heating rate of 100 ℃/min, and preserving the temperature for 10min at 300 ℃; then heating from 300 ℃ to 1000 ℃ at the heating rate of 100 ℃/min, keeping the temperature for 30min, and continuously pressurizing and cooling; the prepared blank is sequentially subjected to surface grinding and deburring treatment, and the prepared vacuum hot-pressing sintered CoCrFeNi (CuTi) with x being 0.4_xHigh entropy alloy block.

Wherein the addition amount of the process control agent in the ball milling process is 0.6-1.2%, and the mass ratio of the ball material is 8-12: 1, wherein the grinding balls are divided into three types of large, medium and small, and the diameters of the grinding balls are 9.5mm, 5mm and 3 mm; the mass ratio of the large, medium and small grinding balls is 2: 3: 5.

CoCrFeNi (CuTi) with x being 0.4_xAfter grinding and polishing the high-entropy alloy material sample, carrying out tissue and performance tests, wherein the obtained technical parameters are shown in table 5;

table 5 results of performance test of the high-entropy alloy material prepared in example 1

Example 6

CoCrFeNi (CuTi) with alloy component x being 0.4_xThe high-entropy alloy powder is subjected to a sintering comparison test.

Co powder, Cr powder, Fe powder, Ni powder, Cu powder and Ti powder with the purity of 99% and the particle size of 44um are used as raw materials, weighed and mixed according to equal atomic ratio to prepare high-entropy alloy mixed powder with the ratio of Co, Cr, Fe, Ni, Cu and Ti being 1:1:1:0.4:0.4, and then ball-milled in a ball mill for 20-24 hours. Putting the mixed powder into a mold, vibrating uniformly and prepressing, putting the mold into a furnace chamber of a rapid hot-pressing sintering furnace for pressure sintering, maintaining the pressure at 30-40 MPa in the sintering process, vacuumizing to the vacuum degree of 1.2pa, raising the temperature from room temperature to 300 ℃ at the heating rate of 100 ℃/min, and preserving the temperature for 10min at 300 ℃; then heating from 300 ℃ to 1000 ℃ at the heating rate of 100 ℃/min, keeping the temperature for 60min, and continuously pressurizing and cooling; the prepared blank is sequentially subjected to surface grinding and deburring treatment, and the prepared vacuum hot-pressing sintered CoCrFeNi (CuTi) with x being 0.4_xHigh entropy alloy block.

Wherein the addition amount of the process control agent in the ball milling process is 0.6-1.2%, and the mass ratio of the ball material is 8-12: 1, wherein the grinding balls are divided into three types of large, medium and small, and the diameters of the grinding balls are 9.5mm, 5mm and 3 mm; the mass ratio of the large, medium and small grinding balls is 2: 3: 5.

CoCrFeNi (CuTi) with x being 0.4_xAfter the high-entropy alloy material sample is ground and polished, carrying out tissue and performance tests, wherein the obtained technical parameters are shown in table 6;

table 6 results of performance test of the high-entropy alloy material prepared in example 1

CoCrFeNi (CuTi) with x being 0.4 prepared in example 3, example 5 and example 6_xThe metallographic OM diagram and the SEM diagram of the high-entropy alloy are shown in the figures 1, 2 and 3; wherein a in fig. 1, 2 and 3 is a gold phase diagram, and b in fig. 1, 2 and 3 is an SEM diagram; wherein FIGS. 1(a) and (b) are microstructure diagrams of example 3, FIGS. 2(a) and (b) are microstructure diagrams of example 5, FIGS. 3(a) and (b) are microstructure diagrams of example 6, and CoCrFeNi (CuTi) having x of 0.4 can be seen from FIGS. 1, 2 and 3_xThe high-entropy alloy block has very uniform structure and higher density, and the optimal sintering temperature of vacuum hot-pressing sintering is higher than that of rapid hot-pressing sintering by about 150 ℃, which may be related to the heating modes of the two devices.

The high-entropy alloy vacuum hot-pressing sintering and rapid hot-pressing sintering molding process with equivalent transformation of double elements adopts two sintering furnaces of vacuum hot-pressing sintering and rapid hot-pressing sintering to sinter and mold high-entropy alloy powder which is uniformly ball-milled under the combined action of heat and force, so that the optimal sintering process is obtained, and alloy blocks with various required components are prepared. The high-entropy alloy block prepared by the method has the advantages of high density, uniform components, fine grains and low cost, can meet the large-scale industrialization requirement, and has important research guidance value for the industrialization development of the high-entropy alloy in the future.

The invention is a high-entropy alloy vacuum hot-pressing sintering and rapid hot-pressing sintering molding process which has the advantages of short flow, low cost, difficult powder oxidation, high density, effective control of grain size, uniform components and large scale size.

The preparation method provided by the invention is simple, high in density, low in production cost, uniform in structure, and capable of effectively avoiding component segregation and obtaining the CoCrFeNi-based high-entropy alloy block material with high hardness and toughness at a low sintering temperature.