New silicon nitride powder synthesis method

Abstract

A new silicon nitride powder synthesis method is disclosed, according to the method, a composite plasma vapor deposition process is used for preparation of nano Si3N4 powder, and the method can avoid the problems of too long heat-insulation nitriding time, too high energy consumption, easy introduction of impurities, and the like of traditional Si3N4 powder synthesis methods. The silicon nitride powder is prepared from SiCl4 or SiBr4 or SiI4 or SiH4 as a raw material by using N2-NH3-Ar as a working gas for forming plasma under 5-55kW power and then rapidly reacting in a plasma reaction vessel at 1000-1400 DEG C. The prepared silicon nitride powder has the advantages of being ultra-fine, high in purity, good in dispersion, less in environmental pollution, and the like, products are powder, and good to collect. Compared with other nano powder material preparation methods, by use of composite plasma enhancement (removal of chemical vapor deposition), the method has the characteristics of low reaction temperature, no pollution to resultants, high product purity, small particle size, high temperature, rapid warming and rapid cooling.

Description

technical field [0001] The invention relates to a method for preparing a novel silicon nitride powder. The method adopts a composite plasma vapor deposition method to prepare a high-purity, ultrafine, and well-dispersed silicon nitride powder, which is suitable for mass production and can be widely used. It is used in the manufacture of high temperature resistant parts, corrosion resistant parts in the chemical industry and other fields. Background technique [0002] As a high-temperature structural material, silicon nitride ceramic material has the advantages of light specific gravity, high temperature and high strength, small thermal expansion coefficient, high elastic modulus, thermal shock resistance, oxidation resistance, corrosion resistance, wear resistance, and good insulation performance. The performance of silicon nitride is comparable to that of high-temperature alloys, and it is mainly used in the manufacture of high-temperature resistant parts and corrosion-resi...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims at solving the above problems, and provides a compound plasma vapor deposition method to prepare silicon nitride powder, which uses different silicon sources and mixed gaseous nitrogen sources as raw materials, and fully reacts in the plasma reaction chamber to obtain silicon nitride powder. After subsequent water treatment to remove excess impurities, high-purity, ultra-fine, and well-dispersed silicon nitride powders are prepared, which effectively solves the above-mentioned shortcomings of silicon nitride powders such as large particle size and low purity.