Different grades of high aspect ratio SiC platelets were used to reinf
orce Si3N4. Dispersion of additives (4 wt % Y2O3 and 3 wt % Al2O3)was
achieved by ball milling in ethanol using alumina balls, while dispers
ion of platelets was done by ball milling using plastic balls. Consoli
dation of the composites was carried out by uniaxial hot pressing. A s
light decrease in flexural strength was measured, while significant in
creases in elastic properties, fracture toughness and Weibull modulus
were noted. Microstructure and crack-propagation studies as well as re
inforcement mechanisms are presented.