Mechanical Properties of TiAl and (TiAl+Ti3 Al) Alloys Produced by Mechanical Alloying

Two representative titanium aluminides containing 48 and 52 at. pct Al were produced by a mechanical alloying (MA) process for the purpose of attaining fine microstructures. For the MA apparatus, an attritor mill and a conventional ball mill were both used and the results compared. Mechanically alloyed powders were consolidated by hot pressing. In addition to morphological changes in the powders during MA, microstructures and mechanical properties of the consolidated products were studied. In particular, the MA alloy with 48 at. pct Al comprised of both TiAl and Ti3Al phases showed a high strain rate sensitivity exponent, above 0.3. This suggests a possibility of developing superplastic deformation.