Tel: +86-510-87330163


Home > Knowledge > Content
Reaction sintering method for Reaction Bonded Silicon Carbide
- Dec 27, 2018 -

The Reaction Bonded Silicon Carbide is a silicon carbide product produced by a reaction sintering method, and the production process of the silicon carbide raw material is quartz (56%), coal char (35%), sawdust (7%), and salt (2). %) mixed together and heated to about 2200 ° C in an electric resistance furnace. The role of salt is to remove impurities in quartz sand and coal char, and the role of sawdust is to generate 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 Reaction Bonded Silicon Carbide can be produced by a reaction sintering method. The α-SiC powder with appropriate particle size ratio and the colloidal graphite were uniformly mixed in a porcelain ball mill for 20 hours, and an alcohol solution of a binder of carboxymethyl cellulose or polyvinyl alcohol was added to form a steel mold, and the pressure was 50-70 MPa.


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 Reaction Bonded Silicon