ABSTRACTExperiments with commercially available as well as with specially prepared Si3N4 -powders were performed in order to estimate the extent of influence of the powder properties and the homogeneity of the additive distribution on the sintering behaviour, the microstructure and on mechanical properties of the dense sintered materials.The quality of the processing steps was examined by dilatometry which also proved to be a useful tool for deducing appropriate sintering conditions for different Si3N4-powder/additive systems.The effects of compositional variations and processing on microstructure and mechanical properties are discussed with respect to strength, reliability (Weibull analysis) and fracture toughness. Some important factors to be considered for the production of highperformance, reliable silicon nitride materials and components are pointed out.The careful analysis of possible influences on the final ceramic resulted in the production of a high-quality Si3N4-material which is used for engine valves, bearing balls, etc.
Microstructure and Mechanical Properties of Microwave Sintered Silicon Nitride