Microstructure and Mechanical Properties of Ternary Ceramic Composites with a ZrC-SiC Matrix

摘要

ZrC-SiC-ZrSi2 ternary ceramic composites were prepared by means of hot pressing. The effect of the ZrSi2 content on the microstructure and mechanical properties of the fabricated materials was investigated. It was found that the addition of ZrSi2 is effective in promoting the sinterability of ZrC-SiC-ZrSi2 ternary composites, and the highest relative density reaches 98.8 % when the ZrSi2 content is 10 vol%. ZrSi2 particles in the microstructure are characterized by an irregular shape with low dihedral angles, which is beneficial for the densification of the composites. The hardness of the composites shows no great variation with the increase in the ZrSi2 content and changes between 14 and 17 GPa. The highest flexural strength, 520 MPa, is obtained for the composite of ZS5Z containing 5 vol% ZrSi2.