MAX phase: alumina composites via elemental and exchange reactions in the Ti_n+1AC_n systems (A=Al, Si, Ga, Ge, In and Sn)

Extension of the aluminothermal exchange reaction synthesis of M_n+1AX_n phases to systems where the element 'A' is not the reducing agent was investigated in systems TiO₂-A-Al-C for A=Al, Si, Ga, Ge, In and Sn as well as Cr₂O₃-Ga-Al-C. MAX phase-Al2O3 composites were made in all systems except those with A=Ga or In. The effectiveness of conversion to MAX phases was generally in the range 63-96% without optimisation of starting ratios. Optimisation in the Ti-Si-C system gave a MAX phase component with >98% Ti₃SiC₂