Preparation method of zirconium boride powder

Abstract

The invention discloses a preparation method of zirconium boride powder. The preparation method comprises the following steps: a, placing B (boron) powder into a graphite crucible with an inner wall coated with BN powder, then placing the graphite crucible with the B powder into a hydrogen reduction furnace, and performing the reduction; b, placing Zr (zinc) powder into the graphite crucible withthe inner wall coated with the BN powder, and reducing in hydrogen; c, ball milling the B powder and the Zr powder prepared in step a and step b according to a molar ratio of 1:1 or 2:1 or 12:1; d, drying the ball milled material; e, heating to 800 to 2400 DEG C at a heating rate of 0.5 to 30 DEG C per minute under the pressure of 10 to 30 GPa, and sintering for 0.5 to 8 hours; f, crushing chromicboride blocks, and filtering by virtue of a 40-mesh to 60-mesh sieve; and g, ball milling and screening the prepared chromic boride particles. By adopting the method of the invention, the high-quality chromic boride powder with complete crystals and a single phase can be prepared.

Description

technical field [0001] The invention relates to a preparation method of zirconium boride powder. Background technique [0002] As a leader in ultra-high temperature ceramic materials, zirconium boride ceramic materials have excellent physical and chemical properties, such as high melting point, high hardness, high stability and corrosion resistance, good electrical and thermal conductivity and neutron control ability, so in Ultra-high-temperature materials, high-temperature structural ceramic materials, composite materials, refractory materials, wear-resistant and corrosion-resistant coatings, high-temperature resistance, electrode materials, cutting materials, neutron absorbers, and packaging materials have broad application prospects. In this regard, many researchers at home and abroad have carried out extensive research on this material. [0003] Zhang Tianmei of Harbin Institute of Technology, in her 2006 master's thesis "Preparation of high-purity zirconium diboride mi...

AI Technical Summary

Problems solved by technology

[0006] (1) During the boron thermal reduction process, element B does not completely combine with element Zr to form zirconium boride, and part of B volatilizes in the form of gaseous oxides. Since element B has the same status as rare earth elements in industrial applications, the price Expensive, so the cost of zirconium boride synthesized by this method is very high

[0007] (2) Before the powder synthesis, the boron powder is finely pretreated by a stirring ball mill, and after the powder synthesis, chemical purification and heat treatment are carried out, which has long process, pollutes the environment and high cost

[0008] (3) The synthesized finished powder contains 1.07wt% oxygen, indicating that this synthesis method cannot obtain a single phase, which will limit the application of this material in production technology

[0012] (1) The chemical purity of the amorphous B powder used is 99.99%. The market price of this high-purity B powder is 10 times that of ordinary B powder. Therefore, the cost of using this raw material for synthesis is very high

[0013] (2) Cold pressing was carried out in the mold before powder synthesis, and the synthesized ZrB 2 The density of the cylinder has reached more than 93%, which increases the difficulty of crushing into powder, which will limit the market application of this material as powder

[0014] (3) During the high-pressure boron thermal reduction process, ZrO 2 The molar ratio of powder and B powder is 3:10, which is much higher than that of ZrB 2 The molar ratio of 1:2, and because of the use of high-purity B powder, will inevitably lead to high cost of synthetic powder

[0015] (4) in ZrB 2 During the preparation of single crystals, high-purity B 2 o 3 powder, and cold pressing, and the direct synthesis of ZrB with Zr powder and B powder 2 Compared with single crystal, the process is longer, the efficiency is lower, and the cost is higher

[0016] According to the binary phase diagram of the boron-zirconium system, zirconium boride ceramics have ZrB, ZrB 2 and ZrB 12 Three kinds of compounds, there are always such and such problems in the preparation method of ZrB2 in current literature or patent, and about ZrB and ZrB 12 There are almost no reports on the preparation method, so a new method with simple process and low energy consumption is used to prepare high-quality zirconium boride powder with complete crystal grains and a single phase in the finished product, so as to improve the industrial application of zirconium boride materials. The application value of the above is really necessary

Images