Pressureless manufacturing of high purity Ti3AlC2 MAX phase material: Synthesis and characterisation

The reported study involves the synthesis of high purity layered ternary carbide Ti3AlC2 MAX phase material by mixing the TiH2, Al and TiC powders in a planetary ball mill followed by two step pressureless sintering in flowing Argon (Ar) atmosphere. XRD and Raman analysis confirms the presence of Ti3AlC2 phase without impurities of Al2O3 and TiC. The morphology studies using SEM confirms the lamellar structure of Ti3AlC2 and EDS measurements shows atomic percentage of Ti, Al and C are in compliance with the XRD phase analysis. X-ray Photoelectron spectroscopy investigations confirm the Ti–C bond. Core level XPS data of Al2p peak show a negative shift indicating electrostatic bonding of Al in Ti3AlC2. Ti2p and C1s core level spectra show the bonding of Mn+1Xn i.e TiC bond. TG-DSC results revealed approximately 7% increase in weight. Ti3AlC2 phase follows an endothermic pattern and does not undergo decomposition upto 1400 °C in vacuum environment. From XRD analysis at different temperatures, it was seen that Al2O3 and TiCx peaks started to form along with Ti3AlC2 at 1000 °C because of selective oxidation of Al into Al2O3. Thus, this study provides a beneficial approach to synthesis of high-purity Ti3AlC2 materials and understanding the thermal behaviour of Ti3AlC2 for high temperature applications.