A kind of preparation method of silicon nitride or silicon nitride/silicon carbide composite powder

Abstract

The present invention involves a method of preparing a silicon nainer or silicon nitride / silicon carbide composite powder.Technical solution 1: Two -~ 30wt%single silicon and 70 ~ 80WT%alkaline metal inorganic salt are used as the raw material, and then the raw material 0 ~ 3WT%catalyst is mixed, dry; then in the nitrogen atmosphere and 1200 ~ 1400 ℃In the conditions, heat preservation of 2 ~ 5h, natural cooling, washing, and silicon powder.Technical solution 2: 5 ~ 15WT%of the substances containing silicon sources, 70 ~ 80WT%alkaline metal inorganic salts, and 5 ~ 15WT%charcoal black as the raw material, plus the catalyst of 0 ~ 3WT%of the raw material, mixing, mixing, mixing, mixing, mixing, mixing, mixing, mixing, mixing, mixing, mixing, mixing, mixing, mixing, mixing, mixing,Dry; then heat thermal insulation under the condition of nitrogen at the atmosphere of nitrogen and 1200 ~ 1400 ° C, naturally cool, wash, and obtain silicon nainer / silicon carbide composite powder.The present invention has the characteristics of low production costs, simple craftsmanship, and easy industrialized production; the prepared silicon nitride or silicon nitrite / silicon carbide composite powder is uniform, good crystal appearance, and high purity purity.

Description

technical field [0001] The invention belongs to the technical field of silicon nitride. Specifically relates to a preparation method of silicon nitride or silicon nitride / silicon carbide composite powder. Background technique [0002] Si 3 N 4 The strong covalent bond characteristics and special structural features of the material make Si 3 N 4 Ceramic materials have the advantages of high specific strength, high specific modulus, high temperature resistance, low thermal conductivity, oxidation resistance and wear resistance, and high thermal shock resistance. They have special use values ​​in working environments with high temperature and high-strength corrosive media. [0003] At present, the key to solving the high cost of silicon nitride materials is to find a suitable way to produce silicon nitride powder in large quantities. Si 3 N 4 Powders can be prepared in many ways: direct nitriding, carbothermal reduction, gas phase and self-propagating methods. The direc...

AI Technical Summary

Problems solved by technology

In recent years Si 3 N 4 / SiC composite powder is mainly synthesized by combustion, which makes the production equipment complex, complex process, long production cycle and high cost