Rapid synthesis of bulk Ti₂AlC by self-propagating high temperature combustion synthesis with a pseudo-hot isostatic pressing process

In this study, the dense polycrystalline Ti₂AlC was synthesized by self-propagating high-temperature combustion synthesis with the pseudo-hot isostatic pressing process (SHS/PHIP). The resultant phase purity is highly dependent on the mol ratio of raw powders. The Ti₂AlC was densified by applying pressure after the SHS reaction. The resultant sample mainly contains typical plate-like nonstoichiometric Ti₂AlC_x (x = 0.69) with grain size of ∼6 μrn. The sample shows the Vickers hardness of 5.8 GPa, highest flexural strength of 432 MPa, compressive strength of 1037 MPa, and fracture toughness of 6.5 MPa·m^1/2. No indentation cracks in Ti₂AlC_x were observed, indicative of a damage material nature. The reaction mechanism for the formation of SHS/PHIP-derived Ti₂AlC is also discussed based on differential thermal analysis and x-ray diffraction results.