EFFECTIVE SINTERING AIDS FOR SI3N4 CERAMICS

Effective sintering aids for Si//3N//4 ceramics are discussed on the basis of reactivities of metal oxide sintering aids with Si//3N//4, which are characterized by comparing the standard free energies for oxidation reactions of Si//3N//4 with those of metals and metal nitrides. The standard free energies of these oxidation reactions are examined, followed by a discussion of the reaction between Si//3N//4 and metal oxides. The discussion shows that reactions between Si//3N//4 and metal oxides around sintering temperatures (2000 K) are important factors in elucidating the roles of sintering aids for Si//3N//4 ceramics.