Mechanical Properties of Si2N2O/SiC‐Whisker Composites

The mechanical and thermal properties of Si 2 N 2 O/SiC‐whisker composites were studied with emphasis on the effect of matrix composition and of whisker content. The fracture toughness of Si 2 N 2 O was remarkably improved by 90% with a concomitant 70% strength improvement by addition of SiC whiskers of only 10 vol%. Optimum mechanical and thermal properties of Si 2 N 2 O/SiC‐whisker composites were obtained at an equimolar ratio of Si 3 N 4 /SiO 2 , which is the stoichiometric composition for Si 2 N 2 O. Additional investigation concerning the Si 2 N 2 O‐matrix/SiC‐whisker interface by controlling sintering additives is necessary for further improvement of mechanical and thermal properties of Si 2 N 2 O/SiC‐whisker composites.