A method for preparing high-purity β-silicon carbide micro-nano powder by carbothermal reduction of high-temperature buried carbon

Abstract

The invention discloses a method for preparing high-purity β-type silicon carbide micro-nano powder by carbothermal reduction of buried carbon at high temperature. Silicon powder and expandable graphite are proportioned and mixed evenly to obtain mixed raw materials; the mixed raw materials are packaged through the crucible and the covering layer composed of graphite paper, refractory cotton and graphite powder; In the sintering furnace, carbothermal reduction reaction occurs at high temperature; after the material is completely cooled, the crucible is taken out, and the covering layer is removed to obtain silicon carbide powder, which is put into the muffle furnace and calcined at high temperature in an oxygen atmosphere; Disperse by means of ball milling; the silicon carbide powder is pickled and washed with water to obtain β-silicon carbide micro-nano powder. In the present invention, the β-type silicon carbide micro-nano powder prepared by the high-temperature embedded carbon carbothermal reduction method is micro-nano level, and the first-level powder is purified and refined, and the yield is high, and the process is simple and the cost is low, and it is suitable for large-scale industrial production. .

Description

technical field [0001] The invention relates to a method for preparing high-purity beta-type silicon carbide micro-nano powder by carbothermic reduction of buried carbon at high temperature, in particular to a preparation technology of beta-type silicon carbide micro-nano powder, and belongs to the technical field of powder material preparation. Background technique [0002] Beta-silicon carbide micro-nano powder has good sintering performance and is an important raw material for the preparation of silicon carbide ceramics. It has a very broad application prospect in the fields of advanced structural ceramics and functional ceramics. The purity, particle size and crystal form of SiC powder have important effects on the quality of grown SiC single crystal and the sintering performance of ceramics. Therefore, the development of high-yield and high-purity β-type silicon carbide micro-nano powder preparation technology is of great significance for the preparation of high-perform...

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Problems solved by technology

The raw materials for the synthesis of β-silicon carbide micro-nano powder by self-propagating synthesis are relatively cheap, and the process is relatively simple, but this method will introduce impurities, which will affect the purity of the powder, the process is difficult to control, and it is easy to cause uneven reaction.

The β-silicon carbide micro-nano powder synthesized by sol-gel carbothermal reduction method has high purity, but the powder prepared by this method has high oxygen content and high cost; the powder synthesized by laser method and plasma method is Nano and submicron powders require high equipment, low output, and high cost; chemical vapor deposition has high cost, low output, and certain technical difficulties

At present, high-purity β-SiC micro-nano powder has problems such as high production cost, low β-phase content, impurities, and difficulty in stable mass production.

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