阅读说明：本技术 一种烧结过渡金属高熵陶瓷氧化物复合材料的制备方法 (Preparation method of sintered transition metal high-entropy ceramic oxide composite material ) 是由 张锐 关莉 王海龙 娄元郑 赵彪 张新月 高前程 冯泽琦 李明亮 范冰冰 于 2021-03-09 设计创作，主要内容包括：本发明公开了一种烧结过渡金属高熵陶瓷氧化物复合材料的制备方法,涉及高熵陶瓷材料技术领域。包括以下步骤：S1、分别称取MgO、CoO、NiO、CuO、ZnO粉体原料,均匀混合后,获得混合粉体；S2、对S1获得的混合粉体预压制坯后,于900～1300℃烧结0.5～1.5h,所述烧结采用微波进行烧结。即得(MgCoNiCuZn)O高熵陶瓷氧化物复合材料。本发明提供的制备方法制得(MgCoNiCuZn)O高熵陶瓷氧化物复合材料,有效的降低了(MgCoNiCuZn)O高熵陶瓷氧化物的合成成本,提高了合成效率。(The invention discloses a preparation method of a sintered transition metal high-entropy ceramic oxide composite material, and relates to the technical field of high-entropy ceramic materials. The method comprises the following steps: s1, weighing MgO, CoO, NiO, CuO and ZnO powder raw materials respectively, and uniformly mixing to obtain mixed powder; and S2, pre-pressing the mixed powder obtained in the step S1 to prepare a blank, and sintering at 900-1300 ℃ for 0.5-1.5 h, wherein the sintering is carried out by adopting microwaves. Obtaining the (MgCoNiCuZn) O high-entropy ceramic oxide composite material. The preparation method provided by the invention can be used for preparing the (MgCoNiCuZn) O high-entropy ceramic oxide composite material, effectively reducing the synthesis cost of the (MgCoNiCuZn) O high-entropy ceramic oxide and improving the synthesis efficiency.)

1. A preparation method of a sintered transition metal high-entropy ceramic oxide composite material is characterized by comprising the following steps:

weighing MgO, CoO, NiO, CuO and ZnO powder raw materials, and uniformly mixing to obtain mixed powder; then, prepressing the mixed powder to prepare a blank, and sintering at 900-1300 ℃ for 0.5-1.5 h to obtain the (MgCoNiCuZn) O high-entropy ceramic oxide composite material; and sintering by adopting microwave.

2. The preparation method of the sintered transition metal high-entropy ceramic oxide composite material according to claim 1, wherein in the microwave sintering process, the wavelength of microwaves is selected to be 1 mm-1 m, the frequency is 915MHz and/or 2450MHz, and the input rate of power is 20-40W/min.

3. The method for preparing a sintered transition metal high-entropy ceramic oxide composite material according to claim 2, wherein a temperature rise rate during sintering is 10 to 30 ℃/min.

4. The preparation method of the sintered transition metal high-entropy ceramic oxide composite material according to claim 1, wherein raw materials are mixed by wet ball milling; wherein the ball-milling ball-material ratio is 3-6: 1, and the rotating speed is 250-310 r/min.

5. The preparation method of the sintered transition metal high-entropy ceramic oxide composite material according to claim 4, wherein the diameters of raw materials of MgO, CoO, NiO, CuO and ZnO powders are all 1-3 μm; the average particle size of the mixed powder after ball milling is 0.1-1 μm.

6. The method for preparing the sintered transition metal high-entropy ceramic oxide composite material according to claim 5, wherein the molar ratio of MgO, CoO, NiO, CuO and ZnO powder is 1:1:1: 1.

7. The preparation method of the sintered transition metal high-entropy ceramic oxide composite material according to claim 1, wherein the mixed powder prepressing blank is prepared by placing the mixed powder in a mold and prepressing for 1-2.5 min under a pressure of 7-12 MPa; wherein the thickness of the blank is 3-6 mm.

8. A sintered transition metal high-entropy ceramic oxide composite material prepared by the preparation method of any one of claims 1 to 7.

9. A sintered transition metal high entropy ceramic oxide composite material according to claim 8, wherein the alloy phase in the composite material is a single phase solid solution.

Technical Field

The invention relates to the technical field of high-entropy ceramic materials, in particular to a preparation method of a sintered transition metal high-entropy ceramic oxide composite material.

Background

The "entropy" is derived from the concept of thermodynamics, and is one of the parameters in thermodynamics, and the physical meaning in thermodynamics is expressed as the degree of disorder of a substance system. The definition of "high entropy" originally originated from high entropy alloys, i.e. materials stabilized by the high configuration entropy of the system. In recent years, the performance of the high-entropy alloy cannot meet the application of aerospace and military industry in certain aspects, and the high-entropy ceramic is produced at present.

The preparation of high-entropy ceramics currently has a plurality of traditional preparation methods, such as plasma activated sintering or muffle furnace sintering, and the sintering methods have the following problems: the method has the disadvantages of difficult process, complex procedure, high temperature requirement, high cost, great pollution, long preparation period and difficult synthesis of single-phase solid solution.

Disclosure of Invention

The invention aims to solve the defects in the background technology, and provides a preparation method of a sintered transition metal high-entropy ceramic oxide composite material, which effectively reduces the synthesis cost of the (MgCoNiCuZn) O high-entropy ceramic oxide and improves the synthesis efficiency.

The first object of the invention provides a preparation method of a sintered transition metal high-entropy ceramic oxide composite material, which comprises the following steps:

weighing MgO, CoO, NiO, CuO and ZnO powder raw materials, and uniformly mixing to obtain mixed powder; then, prepressing the mixed powder to prepare a blank, and sintering at 900-1300 ℃ for 0.5-1.5 h to obtain the (MgCoNiCuZn) O high-entropy ceramic oxide composite material;

and sintering by adopting microwave.

Preferably, in the microwave sintering process, the wavelength of the selected microwave is 1 mm-1 m, the frequency is 915MHz and/or 2450MHz, and the input rate of the power is 20-40W/min.

More preferably, the temperature rise rate during sintering is 10 to 30 ℃/min.

Preferably, the raw materials are mixed by adopting a wet ball milling mode; wherein the ball-milling ball-material ratio is 3-6: 1, and the rotating speed is 250-310 r/min.

More preferably, the diameters of the MgO, CoO, NiO, CuO and ZnO powder raw materials are all 1-3 μm; the average particle size of the mixed powder after ball milling is 0.1-1 μm.

More preferably, the molar ratio of the MgO, CoO, NiO, CuO and ZnO powders is 1:1:1:1: 1.

Preferably, the mixed powder prepressing blank is prepared by putting the mixed powder into a die and prepressing for 1-2.5 min under the pressure of 7-12 MPa; wherein the thickness of the blank is 3-6 mm.

The second purpose of the invention is to provide a sintered transition metal high-entropy ceramic oxide composite material.

Preferably, the alloy phase in the composite material is a single-phase solid solution.

Compared with the prior art, the invention has the beneficial effects that:

the preparation method provided by the invention can be used for preparing the (MgCoNiCuZn) O high-entropy ceramic oxide composite material, effectively reducing the synthesis cost of the (MgCoNiCuZn) O high-entropy ceramic oxide and improving the synthesis efficiency.

The alloy phase in the (MgCoNiCuZn) O high-entropy ceramic composite material provided by the invention is a single-phase solid solution.

Drawings

FIG. 1 is an XRD diagram of a microwave sintered transition metal (MgCoNiCuZn) O high-entropy ceramic oxide composite material obtained in example 1 of the present invention.

FIG. 2 is an XRD diagram of a microwave sintered transition metal (MgCoNiCuZn) O high-entropy ceramic oxide composite material obtained in example 2 of the present invention.

FIG. 3 is an XRD diagram of a microwave sintered transition metal (MgCoNiCuZn) O high-entropy ceramic oxide composite material obtained in example 3 of the present invention.

FIG. 4 is an SEM image of a microwave sintered transition metal (MgCoNiCuZn) O high-entropy ceramic oxide composite material obtained in example 1 of the present invention.

FIG. 5 is an XRD pattern of a microwave sintered transition metal (MgCoNiCuZn) O high-entropy ceramic oxide composite material obtained in comparative example 1.

FIG. 6 is an SEM image of a microwave sintered transition metal (MgCoNiCuZn) O high-entropy ceramic oxide composite material obtained in comparative example 1.

Detailed Description

In order to make the technical solutions of the present invention better understood and implemented by those skilled in the art, the present invention is further described below with reference to the following specific embodiments and the accompanying drawings, but the embodiments are not meant to limit the present invention.

It should be noted that the experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials used are commercially available, unless otherwise specified.

Example 1

A preparation method of a sintered transition metal high-entropy ceramic oxide composite material comprises the following steps:

respectively weighing MgO, CoO, NiO, CuO and ZnO powder as raw materials according to a molar ratio of 1:1:1:1, mixing the raw materials by adopting a wet ball milling mode, wherein the ball-material ratio of ball milling is 5:1, and the rotating speed is 300r/min to obtain mixed powder; wherein the average diameter of MgO, CoO, NiO, CuO and ZnO particles in the mixed powder is 1-3 μm; after ball milling, the average particle size of the mixed powder is 0.1-1 μm;

weighing 30g of mixed powder, pressing a block blank in a grinding tool at room temperature, keeping the pressure at 10MPa for 1.5min, then releasing the pressure, wherein the thickness of the blank is 5mm, sintering the block by using microwaves, adding a heat preservation structure, wherein the sintering temperature is 1300 ℃, the temperature is preserved for 30min, the wavelength range of the microwaves is 0.5m, the frequency is 915MHz, the input rate of power is set to be 30w/min, and the heating rate is 20 ℃/min; obtaining the (MgCoNiCuZn) O high-entropy ceramic oxide composite material.

Example 2

The method is the same as the embodiment 1, except that 20g of mixed powder is taken, a block blank is pressed in a grinding tool at room temperature, the pressure is 7MPa, the pressure is maintained for 1min, the pressure is released, the thickness of the blank is 6mm, the block is sintered by microwaves, a heat insulation structure is added, the sintering temperature is 900 ℃, and the heat insulation is carried out for 40 min;

the wavelength range of the microwave is 1m, the frequency is 2450MHz, the input rate of the power is set to be 40w/min, and the heating rate is 30 ℃/min.

Example 3

The method is the same as the embodiment 1, except that 10g of mixed powder is taken, a block blank is pressed in a grinding tool at room temperature, the pressure is 12MPa, the pressure is maintained for 2.5min, the pressure is released, the thickness of the blank is 3mm, the block is sintered by microwaves, a heat insulation structure is added, the sintering temperature is 1000 ℃, and the temperature is kept for 20 min;

the wavelength range of the microwave is 1mm, the frequency is 915MHz and 2450MHz, the input rate of the power is set to be 20w/min, and the heating rate is 10 ℃/min.

Comparative example 1

The same as in example 1, except that the sintering temperature was 800 ℃.

Comparative example 2

The same as example 2, except that pressureless sintering was used, the sintering temperature was 1000 ℃ and the sintering time was 6 hours.

In order to illustrate the relevant properties of the composite material prepared by the preparation method of the sintered transition metal high-entropy ceramic oxide composite material, the composite materials provided in examples 1 to 3 were tested.

Wherein, the phases of the (MgCoNiCuZn) O high-entropy ceramic composite materials of the examples 1 to 3 and the comparative example 1 are characterized by adopting a SmartLab type X-ray diffraction analyzer (XRD) of Nippon science and electric machinery corporation, and then the phase compositions of the raw materials and the final (MgCoNiCuZn) O high-entropy ceramic composite materials prepared under different variables are obtained by analysis, as shown in figures 1 to 6,

XRD test results of the microwave sintered (MgCoNiCuZn) O high-entropy ceramic composite material in example 1 are shown in FIG. 1, XRD test results of the microwave sintered (MgCoNiCuZn) O high-entropy ceramic composite material in example 2 are shown in FIG. 2, and XRD test results of the microwave sintered (MgCoNiCuZn) O high-entropy ceramic composite material in example 3 are shown in FIG. 3. The microscopic morphology of example 1 was examined and analyzed by a Scanning Electron Microscope (SEM) model JSM-7001F from Japan Electron Co., Ltd., and FIG. 4 is the microscopic morphology of example 1.

As can be seen from FIG. 1, the obtained (MgCoNiCuZn) O high-entropy ceramic composite material has few other peaks, and the main crystal phase is obvious, which shows that the (MgCoNiCuZn) O high-entropy ceramic composite material has already been synthesized.

As can be seen from FIGS. 2 and 3, the obtained (MgCoNiCuZn) O high-entropy ceramic composite material has no other impurity peaks, and the raw materials form a single-phase solid solution, which shows that the single-phase (MgCoNiCuZn) O high-entropy ceramic composite material has been synthesized, and also shows that no other impurities are introduced in the sintering preparation process. The preparation of the (MgCoNiCuZn) O high-entropy ceramic composite material is influenced by the sintering temperature and the tabletting quality.

FIG. 4 is an SEM image of a microwave sintered transition metal (MgCoNiCuZn) O high-entropy ceramic oxide composite material obtained in example 1. As can be seen from fig. 4, the crystal grains coarsened to form a continuous crystal grain structure, the crystal grain size sharply increased, and the rock-salt structure was homogenized and densified.

FIG. 5 is an XRD pattern of a microwave sintered transition metal (MgCoNiCuZn) O high-entropy ceramic oxide composite material obtained in comparative example 1. As can be seen from FIG. 5, under the experimental conditions, only part of the substances in the raw materials are reacted or form new substances, and the single-phase (MgCoNiCuZn) O high-entropy ceramic oxide composite material is not formed.

FIG. 6 is an SEM image of a microwave sintered transition metal (MgCoNiCuZn) O high-entropy ceramic oxide composite material obtained in comparative example 1. As can be seen from fig. 6, under this experimental condition, the phases of the crystal grains are disordered and uneven, only part of the substances in the raw material are reacted or form new substances, and the single-phase (MgCoNiCuZn) O high-entropy ceramic oxide composite material is not formed.

In conclusion, by comparing example 1 and comparative example 1, it is demonstrated that the formation of a (MgCoNiCuZn) O high entropy ceramic oxide composite is related to its temperature; by comparing example 2 and comparative example 2, the advantages of microwave sintered (MgCoNiCuZn) O high-entropy ceramic oxide composite material, namely shorter time and higher efficiency, are demonstrated.

The invention aims to provide a novel ceramic preparation method for sintering a high-entropy ceramic composite material by using microwaves, and has the advantages that the microwave sintering absorbs microwaves by using the dielectric loss of a substance per se to heat the volume, the synthesis speed is high, the synthesis efficiency is high, the synthesis cost of the (MgCoNiCuZn) O high-entropy ceramic oxide is effectively reduced, and the synthesis efficiency is improved.

The present invention describes preferred embodiments and effects thereof. Additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.