PROCESSING, MICROSTRUCTURE AND MECHANICAL-PROPERTIES OF SIC PLATELET-REINFORCED 3Y-TZP COMPOSITES

A study has been carried out on the processing of silicon carbide plat elet-reinforced yttria-stabilised zirconia ceramics, using slip castin g techniques followed by cold isostatic pressing and pressureless sint ering. Optimisation of the process variables, in particular the stabil ity and homogeneity of the composite slurry and mould configuration, e nabled samples with good platelet alignment and densities >96% of theo retical to be produced routinely after pressureless sintering. The por e formation and desintering phenomena in the presence of platelets are explained in relation to the microscopy and dilatometry results. The decreases in the room-temperature fracture toughness and flexural stre ngth with increasing platelet content are attributed to the reduction in transformation hardening and the increase in porosity.