Mechanochemical synthesis mechanism of Ti3AlC2 MAX phase from elemental powders of Ti, Al and C

Abstract

In this study, the synthesis of Ti3AlC2 MAX phase in Ti–Al–C system was investigated by high-energy ball milling. To this aim, mixtures of Ti, Al and C with stoichiometric ratios were milled by a planetary ball mill for different milling times up to 10h. The structural evaluation of powder particles, after different milling times, was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS) and measurement of vial temperature. Thermodynamic investigations showed that direct reactions among elemental powders of titanium, aluminum, and carbon were strongly exothermic and the product phases were formed in a self-sustaining regime. The experimental result showed that after 10h milling the elemental powders reacted together through a rapid combustion reaction process resulting in the formation of Ti3AlC2 and TiC. It was proved that mechanically induced self-propagating reaction (MSR) is dominant mechanism.