Phase evolution during the nitridation of silicon with a clay additive

摘要

A clay additive may assist shape forming of silicon nitride bonded silicon carbide (SNBSC) components, but it grossly complicates the reaction-bonding processes. This paper concentrations on one aspect of bond formation in such a system, namely the effects of clay on the nitridation of silicon. To prevent the potential for carbothermal nitridation-reduction, silicon carbide was excluded from sample formulations. In essence, the melting of the clay by 1000 deg.C was suggested to initiate nitridation earlier and hasten the initial reaction by increasing the local partial pressures of Si(g) and SiO(g).