阅读说明：本技术 一种高熵硼化物粉末及其制备方法 (High-entropy boride powder and preparation method thereof ) 是由 聂金凤 智雅婷 范勇 曹阳 周浩 李玉胜 赵永好 于 2020-12-31 设计创作，主要内容包括：本发明属于高熵陶瓷材料领域,具体涉及一种高熵硼化物粉末及其制备方法。包括如下步骤：步骤(1)：称取原料：按比例称取工业纯铝,过渡金属颗粒和铝-硼二元中间合金；步骤(2)：熔炼：将步骤(1)称取的原料放入真空电弧炉的水冷铜坩埚中,熔炼得到铝合金锭；步骤(3)：萃取：使用盐酸溶液对步骤(2)得到的铝合金锭进行萃取,得到高熵硼化物的粉末。本发明利用过渡金属元素与铝熔体中的硼元素之间的原位化学反应形成高熵硼化物；然后将上述含有高熵硼化物的铝合金锭用盐酸进行腐蚀,将萃取物烘干,即得到黑色的高熵硼化物粉末；本发明具有工艺简单、成本低、生产效率高的特点。(The invention belongs to the field of high-entropy ceramic materials, and particularly relates to high-entropy boride powder and a preparation method thereof. The method comprises the following steps: step (1): weighing the following raw materials: weighing industrial pure aluminum, transition metal particles and aluminum-boron binary intermediate alloy according to a proportion; step (2): smelting: putting the raw materials weighed in the step (1) into a water-cooled copper crucible of a vacuum arc furnace, and smelting to obtain an aluminum alloy ingot; and (3): and (3) extraction: and (3) extracting the aluminum alloy ingot obtained in the step (2) by using a hydrochloric acid solution to obtain high-entropy boride powder. The method utilizes the in-situ chemical reaction between the transition metal element and the boron element in the aluminum melt to form the high-entropy boride; then corroding the aluminum alloy ingot containing the high-entropy boride with hydrochloric acid, and drying the extract to obtain black high-entropy boride powder; the invention has the characteristics of simple process, low cost and high production efficiency.)

1. A preparation method of high-entropy boride powder is characterized by comprising the following steps:

step (1): weighing the following raw materials: weighing industrial pure aluminum, transition metal particles and aluminum-boron binary intermediate alloy according to a proportion;

step (2): smelting: putting the raw materials weighed in the step (1) into a water-cooled copper crucible of a vacuum arc furnace, and smelting to obtain an aluminum alloy ingot;

and (3): and (3) extraction: and (3) extracting the aluminum alloy ingot obtained in the step (2) by using a hydrochloric acid solution to obtain high-entropy boride powder.

2. The method of claim 1, wherein the transition metal is Ti, Cr, V, Zr, Fe.

3. The method according to claim 2, wherein the raw materials in step (1) are specifically composed of: 15.04-63.98% of industrial pure aluminum by mass, 33.34-71.42% of aluminum-boron intermediate alloy by mass, 3-7% of boron element in the aluminum-boron intermediate alloy by mass, 0.5-2.54% of Fe by mass, 0.46-2.36% of Cr by mass, 0.46-2.32% of V by mass, 0.82-4.14% of Zr by mass and 0.44-2.18% of Ti by mass, wherein the Ti, the Cr, the V, the Zr and the Fe are in equal molar ratio.

4. The method of claim 3, wherein step (2) comprises the steps of:

step (21): before weighing, grinding and ultrasonically cleaning the raw materials to prevent oil stains and oxides;

step (22): putting the material weighed in the step (1) into a water-cooled copper crucible of a vacuum arc furnace; placing pure Ti particles for oxygen absorption in another water-cooled copper crucible;

step (23): vacuumizing the electric arc furnace, and flushing inert gas argon;

step (24): starting a smelting direct-current power switch, and smelting pure Ti particles to absorb residual oxygen in a furnace cavity; then smelting industrial pure aluminum, aluminum-boron alloy and each transition metal simple substance to complete reaction, and obtaining an aluminum alloy ingot containing transition metal boride after cooling and solidification;

step (25): and (5) overturning the aluminum alloy ingot, and repeating the steps (22) to (24) for 3-5 times to obtain the aluminum alloy ingot with uniform tissue.

5. The method according to claim 4, characterized in that said step (23) is in particular: vacuumizing the arc furnace to a vacuum degree of more than 5 × 10^-3And when Pa is needed, filling inert gas argon until the pressure in the furnace is negative 0.05 Pa.

6. The method as claimed in claim 5, wherein the melting current in step (24) is 100-250A, and the melting time is 1-3 minutes.

7. The method of claim 1, wherein the process parameters of the extraction in the step (3) are: and (3) placing the aluminum alloy ingot obtained in the step (2) into a hydrochloric acid solution with the volume fraction of 20% -40%, after the aluminum matrix is completely corroded, washing and extracting the aluminum alloy ingot with ionized water and alcohol for 3-5 times to obtain a black substance, and drying the extract at the temperature of 60-80 ℃ for 7-11 hours to obtain high-entropy boride powder.

8. A high entropy boride powder produced by the method of any one of claims 1 to 6.

9. Powder according to claim 8, characterized in that the average size of the high-entropy boride particles is between 0.1 μm and 10 μm.

Technical Field

The invention belongs to the field of high-entropy ceramic materials, and particularly relates to high-entropy boride powder and a preparation method thereof.

Background

Since the high entropy concept was proposed in 2004, it was applied to the development of various materials including metal materials and ceramic materials, and has been a hot spot in the research field of materials in view of the novel property brought to the materials by the high entropy effect. Compared with the traditional ceramics, the high-entropy ceramics has a series of excellent performances such as high melting point, high hardness, low thermal conductivity, oxidation resistance and the like, and has very wide application prospect.

Currently, the research on high-entropy ceramic materials mainly focuses on high-entropy oxides, high-entropy borides, high-entropy carbides and the like. Among them, the research of high-entropy boride is mainly focused on elements of transition groups IVB, VB and VIB. The high-entropy boride powder is obtained at home and abroad mainly by mechanical alloying ball milling, sintering technology and the like, for example, Zhang et al reported that Hf (Hf) is obtained by performing spark plasma sintering at 2000 ℃ after ball milling for 24 hours at 1600 ℃ by using boron thermal reduction in the text of "script Material" 164(2019): 135-_0.2Zr_0.2Ta_0.2Cr_0.2Ti_0.2)B₂And (3) powder.

Most of the existing methods have high preparation cost, multiple operation procedures, long time and low efficiency, and the problems of oxidation pollution and the like are easy to occur in the process, so that the industrial application is not easy to realize. There is therefore a need for a production process which can achieve high yields at low cost and which is easy to control the particle size of the high-entropy borides.

Disclosure of Invention

The invention aims to provide a preparation method of high-entropy boride powder with low cost, high yield, simple and convenient process operation and easy control, and the high-entropy boride powder prepared by the preparation method.

The technical solution for realizing the purpose of the invention is as follows: a preparation method of high-entropy boride powder comprises the following steps:

step (1): weighing the following raw materials: weighing industrial pure aluminum, Ti, Cr, V, Zr and Fe elementary substance blocks and aluminum-boron binary intermediate alloy according to the proportion;

step (2): smelting: putting the raw materials weighed in the step (1) into a water-cooled copper crucible of a vacuum arc furnace, and smelting to obtain an aluminum alloy ingot;

and (3): and (3) extraction: and (3) extracting the aluminum alloy ingot obtained in the step (2) by using a hydrochloric acid solution to obtain high-entropy boride powder.

Further, the raw materials in the step (1) specifically comprise: 15.04-63.98% of industrial pure aluminum by mass, 33.34-71.42% of aluminum-boron intermediate alloy by mass, 3-7% of boron element in the aluminum-boron intermediate alloy by mass, 0.5-2.54% of Fe by mass, 0.46-2.36% of Cr by mass, 0.46-2.32% of V by mass, 0.82-4.14% of Zr by mass and 0.44-2.18% of Ti by mass, wherein the Ti, the Cr, the V, the Zr and the Fe are in equal molar ratio.

Further, the step (2) comprises the following steps:

step (21): before weighing, grinding and ultrasonically cleaning the raw materials to prevent oil stains and oxides;

step (22): putting the material weighed in the step (1) into a water-cooled copper crucible of a vacuum arc furnace; placing pure Ti particles for oxygen absorption in another water-cooled copper crucible;

step (23): vacuumizing the electric arc furnace, and flushing inert gas argon;

step (24): starting a smelting direct-current power switch, and smelting pure Ti particles to absorb residual oxygen in a furnace cavity; then smelting industrial pure aluminum, aluminum-boron alloy and each transition metal simple substance to complete reaction, and obtaining an aluminum alloy ingot containing transition metal boride after cooling and solidification;

step (25): and (5) overturning the aluminum alloy ingot, and repeating the steps (22) to (24) for 3-5 times to obtain the aluminum alloy ingot with uniform tissue.

Further, the step (23) is specifically: vacuumizing the arc furnace to a vacuum degree of more than 5 × 10^-3And when Pa is needed, filling inert gas argon until the pressure in the furnace is negative 0.05 Pa.

Further, the smelting current in the step (24) is 100-250A, and the smelting time is 1-3 minutes.

Further, the process parameters of the extraction in the step (3) are as follows: and (3) placing the aluminum alloy ingot obtained in the step (2) into a hydrochloric acid solution with the volume fraction of 20% -40%, after the aluminum matrix is completely corroded, washing and extracting the aluminum alloy ingot with ionized water and alcohol for 3-5 times to obtain a black substance, and drying the extract at the temperature of 60-80 ℃ for 7-11 hours to obtain high-entropy boride powder.

High-entropy boride powder prepared by the method.

Further, the average size of the high-entropy boride particles is 0.1 μm to 10 μm.

The principle of synthesizing the high-entropy boride in the method is as follows: transition metal elements (Ti/Zr/Fe/Cr/V) in the aluminum melt and B atoms in a dissolved state in the alloy melt are subjected to chemical reaction, and all the transition elements in the melt around the aluminum melt participate in the chemical reaction together in the reaction, so that a large amount of high-entropy boride particles can be formed in situ in the aluminum alloy melt at a lower temperature, the distribution of all the elements in the particles is relatively uniform, and the particle size of the high-entropy boride is regulated and controlled by controlling the temperature and time of the reaction.

Compared with the prior art, the invention has the remarkable advantages that:

(1) the method adopts an in-situ reaction method to synthesize the high-entropy boride in the aluminum alloy melt, utilizes spontaneous exothermic reaction between transition metal elements in the melt and boron elements in a dissolved state to form crystal particles of the high-entropy boride, and can grow in an aluminum melt environment according to the growth habit of the crystal particles; and further, the crystal powder of the high-entropy boride is obtained by corroding the matrix, and compared with the existing preparation method, the method has the advantages of stable process, convenience in operation, good crystallinity and high purity of the high-entropy boride, and can regulate and control the size of particles by controlling reaction time.

(2) The preparation method is energy-saving, environment-friendly and low in cost, and is suitable for industrial production and application.

Detailed Description

The invention is realized by the following modes: a preparation method of high-entropy boride is characterized by comprising the following steps:

weighing: weighing the following raw materials in percentage by mass according to the mass percentage of boron element (mass fraction is 1% -5%): the aluminum-boron alloy material comprises, by mass, 15.04% -63.98% of industrial pure aluminum, 33.34% -71.42% of aluminum-boron intermediate alloy (wherein the mass fraction of boron elements in the aluminum-boron intermediate alloy is 3% -7%), 0.5% -2.54% of high-purity transition metal element simple substance Fe, 0.46% -2.36% of Cr, 0.46% -2.32% of V, 0.82% -4.14% of Zr and 0.44% -2.18% of Ti, wherein the molar ratios of Ti, Cr, V, Zr and Fe are equal, and a certain amount of pure Ti particles are weighed to remove residual oxygen in an arc furnace. Before weighing, the raw materials are polished and cleaned by ultrasonic waves to prevent oil stains, oxides and the like from influencing experimental results.

Smelting in step (2):

1) putting the material weighed in the step (1) into a water-cooled copper crucible of a vacuum arc furnace; placing pure Ti particles for oxygen absorption in another water-cooled copper crucible;

2) vacuumizing the arc furnace to a vacuum degree of more than 5 × 10^-3When Pa, filling inert gas argon until the pressure in the furnace is negative 0.05 Pa;

3) starting a smelting direct-current power switch, smelting pure Ti particles to absorb residual oxygen in the furnace cavity, and further improving the vacuum degree; then smelting industrial pure aluminum, aluminum-boron alloy and each transition metal simple substance to complete reaction, and obtaining an aluminum alloy ingot containing transition metal boride after cooling and solidification, wherein: the smelting current is 100-250A, and the smelting time is 1-3 minutes.

4) And (3) overturning the alloy ingot, and repeating the step 2)3) for 3-5 times to obtain the aluminum alloy ingot with uniform tissue.

And (3) extraction: and (3) placing the aluminum alloy ingot obtained in the step (2) in a hydrochloric acid solution with the volume fraction of 20% -40%, after the aluminum matrix is completely corroded, washing and extracting the aluminum alloy ingot with ionized water and alcohol for 3-5 times to obtain a black substance, and drying the extract at the temperature of 60-80 ℃ for 7-11 hours to obtain high-entropy boride powder.

Example 1

The method is characterized in that Al-3B intermediate alloy with the boron element of 3 percent in mass fraction is used as a raw material, and the specific implementation steps are as follows:

weighing: weighing the following raw materials according to the mass percent of boron element of 1 percent: the aluminum-boron alloy material comprises, by mass, 63.98% of industrial pure aluminum, 33.34% of aluminum-boron intermediate alloy, 0.5% of high-purity transition metal element elementary substance Fe, 0.46% of Cr, 0.46% of V, 0.82% of Zr and 0.44% of Ti.

Smelting in step (2):

1) putting the material weighed in the step (1) into a water-cooled copper crucible of a vacuum arc furnace; placing pure Ti particles for oxygen absorption in another water-cooled copper crucible;

2) vacuumizing the arc furnace to a vacuum degree of more than 5 × 10^-3When Pa, filling inert gas argon until the pressure in the furnace is negative 0.05 Pa;

3) starting a smelting direct-current power switch, smelting pure Ti particles to absorb residual oxygen in the furnace cavity, and further improving the vacuum degree; then smelting industrial pure aluminum, aluminum-boron alloy and each transition metal simple substance to complete reaction, and obtaining an aluminum alloy ingot containing transition metal boride after cooling and solidification, wherein: the melting current was 250A, and the melting time was 3 minutes.

4) And (3) overturning the alloy ingot, and repeating the step 2)3) for 3 times to obtain the aluminum alloy ingot with uniform tissue.

And (3) extraction: and (3) placing the aluminum alloy ingot obtained in the step (2) in a hydrochloric acid solution with the volume fraction of 20%, after the aluminum matrix is completely corroded, washing and extracting the aluminum alloy ingot with ionized water and alcohol for 3 times to obtain a black substance, and drying the extract at 60 ℃ for 11 hours to obtain high-entropy boride powder.

Example 2

The method is characterized in that Al-5B intermediate alloy with 5 mass percent of boron is used as a raw material, and the method comprises the following specific implementation steps:

weighing: weighing the following raw materials according to the mass percent of the boron element of 3 percent: the aluminum-boron alloy material comprises, by mass, 31.9% of industrial pure aluminum, 60% of an aluminum-boron intermediate alloy, 1.52% of high-purity transition metal element elementary substance Fe, 1.42% of Cr, 1.38% of V, 2.48% of Zr and 1.3% of Ti.

Smelting in step (2):

1) putting the material weighed in the step (1) into a water-cooled copper crucible of a vacuum arc furnace; placing pure Ti particles for oxygen absorption in another water-cooled copper crucible;

2) vacuumizing the arc furnace to a vacuum degree of more than 5 × 10^-3When Pa, filling inert gas argon until the pressure in the furnace is negative 0.05 Pa;

3) starting a smelting direct-current power switch, smelting pure Ti particles to absorb residual oxygen in the furnace cavity, and further improving the vacuum degree; then smelting industrial pure aluminum, aluminum-boron alloy and each transition metal simple substance to complete reaction, and obtaining an aluminum alloy ingot containing transition metal boride after cooling and solidification, wherein: the smelting current is 150A, and the smelting time is 2 minutes.

4) And (3) overturning the alloy ingot, and repeating the step 2) for 3)4 times to obtain the aluminum alloy ingot with uniform tissue.

And (3) extraction: and (3) placing the aluminum alloy ingot obtained in the step (2) in a hydrochloric acid solution with the volume fraction of 30%, after the aluminum matrix is completely corroded, washing and extracting the aluminum alloy ingot with ionized water and alcohol for 4 times to obtain a black substance, and drying the extract at 70 ℃ for 9 hours to obtain high-entropy boride powder.

Example 3

The preparation method comprises the following specific implementation steps of taking Al-7B intermediate alloy with 7 mass percent of boron as a raw material:

weighing: weighing the following raw materials according to the mass percent of the boron element of 5 percent: the aluminum-boron alloy material comprises, by mass, 15.04% of industrial pure aluminum, 71.42% of an aluminum-boron intermediate alloy, 2.54% of high-purity transition metal element elementary substance Fe, 2.36% of Cr, 2.32% of V, 4.14% of Zr and 2.18% of Ti.

Smelting in step (2):

1) putting the material weighed in the step (1) into a water-cooled copper crucible of a vacuum arc furnace; placing pure Ti particles for oxygen absorption in another water-cooled copper crucible;

2) vacuumizing the arc furnace to a vacuum degree of more than 5 × 10^-3When Pa, filling inert gas argon until the pressure in the furnace is negative 0.05 Pa;

3) starting a smelting direct-current power switch, smelting pure Ti particles to absorb residual oxygen in the furnace cavity, and further improving the vacuum degree; then smelting industrial pure aluminum, aluminum-boron alloy and each transition metal simple substance to complete reaction, and obtaining an aluminum alloy ingot containing transition metal boride after cooling and solidification, wherein: the smelting current is 100A, and the smelting time is 3 minutes.

4) And (3) overturning the alloy ingot, and repeating the step 2) for 3)5 times to obtain the aluminum alloy ingot with uniform tissue.

And (3) extraction: and (3) placing the aluminum alloy ingot obtained in the step (2) in a hydrochloric acid solution with the volume fraction of 40%, after the aluminum matrix is completely corroded, washing and extracting the aluminum alloy ingot with ionized water and alcohol for 5 times to obtain a black substance, and drying the extract at the temperature of 80 ℃ for 7 hours to obtain high-entropy boride powder.