1994 Volume 80 Issue 5 Pages 424-429
The effects of thermo-mechanical treatment on the tensile ductility at room temperature were investigated in the three binary γ-base titanium aluminides containing different volume fraction of α2 phase. The tensile ductility at room temperature was improved by the formation of fine and homogenious "duplex" microstructure, which was optimised by the high reduction of forging and the adequate heat treatment temperature. The effect was most remarkable on the stoichiometric composition containing less α2 content than Ti-rich composition. In the duplex microstructure, deformation was taken upon the equi-axed γ grains rather than the lamellar region. However, the fracture mode was still brittle even in the specimen showing the high elongation of 7.8%.
