Thermodynamic predictions for the manufacture of Ti2AlC MAX-phase ceramic by combustion synthesis

This paper presents an analysis of the SHS reaction for the manufacture of Ti2AlC MAX phase materials using self-propagating high-temperature synthesis (SHS). Enthalpy-temperature calculations are presented for the reaction 2Ti + (1 + y)Al + C → Ti2AlC + yAl. The analysis and data presented allows the determination of the adiabatic combustion temperature as a function of a variety of conditions including (i) reactant pre-heating to increase the combustion temperature or (ii) the addition of excess aluminium as a diluent to reduce the combustion temperature. As excess Al is added as a diluent, there is a decrease in Tad but it offers the potential to control the exothermicity of the SHS process and to form metal–ceramic composites. The range of criteria used for the determination of the appropriate combustion condition for SHS, such as Tad ⩾ 1800 K and -ΔHr298K/Cp298K≥2000K, are shown to be applicable for Ti2AlC MAX phase ceramics. The data presented is of use to those considering the manufacture of novel MAX phase ceramics by SHS.