Published online by Cambridge University Press: 26 February 2011
TiAl (γ) intermetallic has been investigated with ternary additions of up to 10 at% Ga. Optical microscopy reveals that gallium can be retained in solution to at least 7 at%. Microhardness data reveals that Ga substituted for Al such that Ti/(Al+Ga)=l causes solution softening. Deformation behavior of the single phase alloy in compression is reported. Perfect dislocations of the a/2[110] type and superdislocations of the a[011] type and a/2[112] type have been observed. TEM results indicate that primary deformation is contributed by a/2[110] type dislocations and twinning on (111) planes with wavy slip optically observed