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Reaction sintering method for Rbsic sisic silicon carbide product
- Oct 24, 2018 -

The Rbsic sisic  silicon carbide product is a silicon carbide product produced by a reaction sintering process, and the raw material used is silicon carbide. Before producing the Rbsic sisic  silicon carbide product, the silicon carbide raw material should be prepared. The specific operation method is to mix quartz, coal char, sawdust and salt together; then, it is placed in an electric resistance furnace and heated to about 2200 ° C, salt. The role is to remove impurities in quartz sand and coal char, and the role of sawdust is to create pores, so that the generated gas easily escapes.


In the middle of the electric furnace, graphite or carbon particles are deposited into a columnar resistance heating element, and the raw materials are closely packed around the heating element. The fired bulk crystals are crushed, washed with acid and alkali, and then magnetically removed to remove a trace amount of iron, and dried to obtain a silicon carbide raw material.


The Rbsic sisic  silicon carbide product can be produced by a reaction sintering method, and the α-SiC powder with a suitable particle size ratio is uniformly mixed with the colloidal graphite in a porcelain ball mill cylinder for 20 hours, and an alcohol solution of the binder carboxymethyl cellulose or polyvinyl alcohol is added. Formed in the mold, the pressure is 50 ~ 70Mpa. The green body was slowly dried at 40 ° C, dried at 100 ° C, and then sintered.


In a carbon tube furnace under atmospheric pressure, silicon powder is placed in a graphite crucible to produce silicon vapor. The silicon powder particles are 4.7 to 1.0 mm, and the silicidation temperature is 2000 ° C or higher. If it is in a 66.6 Pa vacuum furnace, the silicon powder should be placed in a boron nitride crucible with a silicidation temperature of 1500 to 1600 °C. The silicon adhering to the surface of the article due to evaporation can be removed by treatment with hot sodium hydroxide to produce a Rbsic sisic  silicon carbide article.