Alumina ceramics toughened by a piezoelectric secondary phase

A process for ceramic toughening is developed, where a selected piezoelectric or ferroelectric secondary phase is incorporated and dispersed in a ceramic matrix as reinforcement. The toughening effect of Nd2Ti2O7 secondary phase on Al2O3 ceramic is determined together with the microstructures and phase constitution of the composite ceramics. Dense composite ceramics can be formed with the secondary phase and the Al2O3 matrix. Compared to single phase Al2O3 ceramics, the Nd2Ti2O7/Al2O3 composite ceramic shows a significant increase in fracture toughness, and KIC reaches 6.7 MPa m1/2 for a composition of 0.03 Nd2Ti2O7/0.97Al2O3.