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 µm. The sample shows the Vickers hardness of 5.5 GPa, highest flexural strength of 431 MPa, compressive strength of 1033 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.