Methods of Fabricating Ceramic Materials.

摘要

Processing parameters are described which allow the fabrication of high density 'Sialon' compositions using conventional ceramic technology amenable to low-cost large-scale production. A processing technique, 'mineralization' is used to incorporate sintering aids into the Al2O3 component of the sialon which facilitates control and minimization of the amount of such additives while simultaneously extending the firing range of the materials. Sialons containing up to 87% by weight of Si3N4 are densified by pressureless sintering in an atmosphere of N2+H2 with negligible weight loss. Properties discussed include bend strength of up to 60,000 psi at room temperature with good strength retention in several compositions to 1400 C and oxidation resistance superior to hot pressed Si3N4. The fabrication of Radome Shapes by slip casting and jiggering and of turbine blade shapes by injection molding are demonstrated. (Author)