Contribution of plastic deformation of Ti3SiC2 to the crack deflection in the Al2O3/Ti3SiC2 composites

The addition of Ti3SiC2 particles can enhance the toughness of Al2O3. The toughening mechanism for the Al2O3/Ti3SiC2 composites is investigated in the present study. Though the Ti3SiC2 particles are constrained by the rigid Al2O3 matrix, crack deflection can still take place within the Ti3SiC2 particles. The toughening effect is mainly contributed by such crack deflection. The experimental results match well with the theoretical prediction. However, in order to allow the crack deflection to take place within Ti3SiC2 particle, the pre-existence of plastic deformation within the particle is essential. The interactions between crack deflection and plastic deformation are discussed.