TENSILE-STRENGTH OF SILICON-NITRIDE WHISKERS SYNTHESIZED BY REACTING AMORPHOUS-SILICON NITRIDE AND TITANIUM-DIOXIDE

The tensile strength of alpha-Si3N4 whiskers synthesized by reacting a morphous Si3N4 and TiO2, at 1490 degrees C under a N-2, pressure of 70 0 torr was measured using a microbalance, and the diameter dependence of the strength was investigated. The Si,N, whiskers had diameters of 0.04 and 0.8 mu m and dominant [10 (1) over bar 1] and [10 (1) over ba r 0] growth directions. Chemical analysis showed that they contained T i and O impurities. The tensile strength of six Si3N4 whiskers increas ed from 17 to 59 GPa with decreasing whisker diameter.