The compressive property and brittle-to-ductile transition of Ti₃SiC₂ ceramics

Compressive tests of polycrystalline Ti₃SiC₂ were performed from room temperature to 1423 K at strain rates of 1x10^-4 s^-1 and 2.5x10^-5 s^-1, respectively. The effect of strain rates on high-temperature compressive property was also investigated. Polycrystalline Ti₃SiC₂ exhibited positive temperature dependence of flow stress (flow stress anomaly) and showed a temperature peak at 1173 K. The brittle-to-ductile transition temperature (BDTT) for polycrystalline Ti₃SiC₂ was strain-rate sensitive, an approximately 100 K decrease in transition temperature was associated with four times of magnitude decrease in strain rate. In addition, the fracture morphology changed from predominately intergranular to mostly transgranular. The mechanism responsible for the brittle-to-ductile transition in Ti₃SiC₂ was involved in the onset of a thermally activated deformation process.