Microstructure and mechanical properties of hot pressed ZrB2-SiCp-ZrO2 composites

The present paper investigated the microstructure and mechanical properties of ZrB2-10 vol.%SiCp-10 vol.%ZrO2 composites hot pressed at three temperatures. Phase transformability from t-ZrO2 to m-ZrO2 during fracture was analyzed through calculating the volume fractions of m-ZrO2 and t-ZrO2 on polished and fracture surfaces. The densification temperature was found to have a significant effect on the microstructure, phase transformation and the properties of the composites. When the composite was hot pressed at 1950 degrees C, the average grain size was 9.5 mu m, and the fracture toughness was 4.5 MPa.m(1/2). Comparatively., when the composite was hot pressed at 1750 degrees C, the average grain size was 3.4 mu m, and the fracture toughness increased by similar to 50% to 6.8 MPa.m(1/2). (c) 2007 Elsevier B.V. All rights reserved.