Synthesis of Ti_2AlC and Ti_3AlC_2 by mechano-chemical reaction and hot pressing process

摘要

The mechanically induced self-propagating reaction (MSR) and hot-pressing consolidation were adapted to synthesize Ti_2AlC and Ti_3AlC_2 using Ti, C and Al powder mixtures. The effects of Al content on the microstructure and mechanical properties of fully dense Ti_2AlC and Ti_3AlC_2 were investigated. The results reveal that the Ti_3AlC_2, TiC and TiAl_x transitional phases were formed by mechanically alloying according to the mechanically induced self-propagating reactions (MSR). Through hot pressing the as-milled powders with initial composition of 2Ti/1.5Al/C and 2Ti/Al/C, respectively, at 1100°C for 1 h, the desired high purity Ti_2AlC and Ti_3AlC_2 were produced. SEM images confirmed that the as-fabricated Ti_2AlC and Ti_3AlC_2 grains are plate-like with nanoscale layered structure and dispersed uniformly.