Fabrication of dense ultrafine TiAl alloys by spark plasma synthesis from mechanically activiated powders

Powder of Ti-46at%Al alloy was synthesized through mechanical activation(MA) and then sintered and concurrently consolidated in a short sintering time of 900 s by using a spark plasma sintering(SPS) process. The XRD and SEM profiles show that the microstructures of TiAl alloys contained gamma TiAl and small amount alpha-2 Ti-3 Al phase, whose amount can be controlled by the sintering temperature. The compacts retained the original fine-grained fully densified bodies by avoiding an excessively high sintering temperature. The alloys sintered at higher temperature with this process showed a coarser microstructure. So it is possible to produce dense nanostructured TiAl alloys by mechanically activated spark plasma sintering (MASPS) within a very short period of time.