Microstructure and mechanical property of diffusion bonded ZrC-SiC joint

ZrC-20%SiC composite ceramic (ZS) was bonded with a pure Ti interlayer. The typical microstructure and interfacial reaction mechanism of the ZS/Ti/ZS joint were analyzed. The effect of bonding temperature on the interfacial microstructure and mechanical property was investigated. The results show that the TiC compound is formed at the interface due to the interaction between Ti and ZrC-SiC composite. The atoms of Zr and Si release as the intermediate products. A portion of Zr atoms are diffused into the TiC layer and the remains are diffused into the Ti interlayer as solid solution atoms. The Ti-Zr-Si phase is formed nearby the ZrC-SiC composite at a higher bonding temperature or a longer bonding time. The thickness of the formed reaction layer increases. The shear strength of the diffusion bonded joints firstly increases and then decreases when the bonding temperature increases from 900°C to 1200°C. The maximal value is 149 MPa when bonded at 1000°C under 20 MPa for 30 min.