In-situ synthesis of Ti3AlC2/TiC-Al2O3 composite from TiO2-Al-C system

Ti3AlC2/TiC-Al2O3 composite was synthesized by a combustion reaction in TiO2-Al-C system. The effect of the compositions in raw materials on the products was investigated. Ti3AlC2/TiC-Al2O3 composite was obtained at the molar ratio of TiO2:Al:C=3.0:5.0 similar to 5.1:1.8 similar to 2.0. The reaction path for the 3TiO(2)-5Al-2C system was proposed. Al3Ti, Ti2O3, TiO, and delta-Al2O3 are found to be transitional phases. Finally, Ti3AlC2/TiC-Al2O3 composite forms at similar to 900 degrees C of furnace temperature. The measured Vickers hardness, fracture toughness, and flexural strength of the nearly dense sample from 3TiO(2)-5Al-2C are 13.3 +/- 1.1 GPa, 5.8 +/- 0.3 MPa(.)m(1/2), and 466 +/- 39 MPa, respectively.