Fabrication of Ce-TZP/Ba hexaaluminate composites using amorphous precursor of the second phase

Abstract

Ce-TZP/BaAl12O19 composites were prepared using an amorphous precursor powder as the starting material of the second phase BaAl12O19. With increase of the weight ratio of the second phase, the average grain size of matrix zirconia decreased markedly from 2.5μm of the monolithic zirconia to 0.62μm of the Ce-TZP/20 wt% BaAl 12O19 composite. Three-point bending strength of the composites was increased by incorporation of second-phase particles. The Ce-TZP/15 wt% BaAl12O19 composite showed a maximum value of 769 MPa. Although fracture toughness of the composites decreased concomitantly with an increase in the weight ratio of the second phase, the degree of the toughness degradation was suppressed by crack deflection effects arising from the incorporated anisotropic second-phase particles. © 2012 The Ceramic Society of Japan. All rights reserved.