Synthesis of Ti2AlC MAX phase and Ti2C MXene by activated combustion

Abstract

The preparation of the Ti2AlC MAX phase by activated self-propagating high-temperature synthesis from a mixture of elemental powders using the thermokinetic coupling approach is reported. The underlying mechanism in the Ti–Al–C system has been elucidated. Ti2C MXene was produced by exfoliation of its MAX counterpart. The combustion wave sensitive parameters were determined, the influence of promoter and ambient gas pressure on the phase composition and evolution of the microstructure was revealed. The Ti2AlC MAX phase was successfully prepared in an energy-efficient pathway with some controlled amount of TiC. The interaction mechanism, simulated at comparatively higher heating rates (β = 600–4800 °C·min−1), demonstrated the evolution of the following phases: Ti3Al, TiC, Ti3AlC, Ti2AlC, T3AlC2, Al3Ti. Etching for only 2h in combination with double ultrasonic treatment made it possible to delaminate the nanolayered structure of the parent MAX phase and obtain Ti2C MXene.