Microstructure and mechanism of damage tolerance for Ti₃SiC₂ bulk ceramics

Abstract

Titanium silicon carbide (Ti₃SiC₂) is a damage tolerance material that is expected to be used in a number of high temperature applications. In this work, the microstructure and damage tolerance mechanism of Ti₃SiC₂ was investigated. The result demonstrated that the Ti₃SiC₂ ceramics prepared by the in-situ hot pressing/solid-liquid reaction process had a dual microstructure, i.e., large laminated grains were distributed within small equiaxial grains. This microstructure is analogous to that of platelets reinforced ceramic matrix composites. The bending test using single-edge-notched-beam specimens revealed that Ti₃SiC₂ was a damage tolerance material. The damage tolerance mechanisms for Ti₃SiC₂ are basal plane slip, grain buckling, crack deflection, crack branching, pull-out and delamination of the laminated grains.

Key words:

• Ti₃SiC₂
• Microstructure
• Damage mechanism
• Crystallite shape