High temperature physical and mechanical properties of large-scale Ti₂AlC bulk synthesized by self-propagating high temperature combustion synthesis with pseudo hot isostatic pressing

The electrical, thermal, and mechanical properties as well as the effect of the temperature of large-scale Ti₂AlC bulk synthesized by self-propagating high temperature combustion synthesis with pseudo hot isostatic pressing were investigated in detail. With increasing temperature, the lattice defects contribute to the decreasing phonon thermal conductivity, and the electrical resistivity increases linearly from room temperature (RT) to 900°C. The RT flexural strength, compressive strength, fracture toughness, work of fracture, and Vickers hardness were measured to be 606±20MPa, 1057±84MPa, 6.9±0.2MPam^1/2, 158±12J/m², and 4.7±0.2GPa, respectively. With increasing temperature, the flexural and compressive strengths both keep almost unchanged in the zone of brittle failure, but decrease sharply as the plastic deformation occurs. The brittle-plastic transition temperature under flexure (900-950°C) is higher than compression (700-800°C). Interestingly, a non-catastrophic failure is observed in the SENB test, with the high work of fracture (158±12J/m²).