Synthesis and microstructure of Ti3AlC2 by mechanically activated sintering of elemental powders

The mechanically activated sintering (MAS) process has been adopted to synthesize Ti3AlC2 by using Ti, Al and graphite elemental powders. These were subjected to mechanical alloying with charge ratios (CR) of 20:1 and 50:1, respectively. Fine powders containing TiC, Ti3AlC2 and Al3Ti were obtained after milling for 4 h with a CR of 20:1, and for 1.5 h with a CR of 50:1. The mechanical alloyed (MAed) powders were pressureless sintered at different temperatures. Ti3AlC2 started to form at 1250 °C and its content increased at 1350 °C. However, it decomposed to TiC at 1450 °C. The microstructure of sintered samples showed that many Ti3AlC2 grains were delaminated and broken. Some severely delaminated Ti3AlC2 grains in which kink bands developed were also found.