Improved Resistance to Damage of Silicon Carbide‐Whisker‐Reinforced Silicon Nitride‐Matrix Composites by Whisker‐Oriented Alignment

The effects of whisker-oriented alignment on resistance to damage of SiC(w)/Si 3 N 4 composites have been investigated by the Vickers indentation method and R-curve behavior. It is shown that increasing the degree of whisker-oriented alignment decreases the lengths of Vickers impressions and indentation cracks. The results exhibit rising R-curve behaviors for the SiC(w)/Si 3 N 4 composites with different degree of whisker-oriented alignment. Moreover, the initial crack length c i , the threshold of crack growth resistance K i , and the upper bound of crack growth resistance K change regularly with increasing degree of whisker-oriented alignment. All results suggest that the whisker-oriented alignment improves the resistance to damage of the composites, resulting in a more reliable and usable composite.