Mechanical properties of Cr, Mn, Fe, Co, and Ni modified titanium trialuminides

To increase gas turbine efficiency, new high-temperature-resistant and lightweight materials are needed. Titanium trialuminides are an interesting option, but they are currently too brittle at room temperature to be used as turbine blades. Brittleness of TiAl3 can be reduced by alloying with several transition metal elements. The effect of ternary additions of Cr, Mn, Fe, Co, or Ni at various stoichiometries (3 to 9 at.%) to the intermetallic TiAl3 is studied by metallography, X-ray diffraction and three-point-bend testing. These methods indicate that the 6 at.% Cr or Co additions give the highest flexural strength with only a small trade-off in failure strain when compared to the 9 at.% additions of chromium and manganese.