Abstract
Effect of Al content on the microstructure and room temperature tensile properties has been investigated using a series of titanium aluminides containing 40 to 53mo1%Al (Mn/Al=0.04) produced via a reactive sintering process. A sodium reduced titanium powder is used as a starting elemental titanium powder.
The alloy having 40mol%A1 exhibits a coarse a2 structure in addition to a duplex structure consisted of the lamellar grains and equiaxed γ grains. When Al content ranges from 42 to 50 mol%, the duplex structure is developed, and the volume fraction of equiaxed γ grains increases with increasing Al content. A single phase structure(equiaxed γ)is observed in the alloy containing 53mo1%Al.
Tensile strength rises with increasing Al content up to 43.4mol%Al, after which the strength drops as Al content is increased. Elongation to fracture shows a similar tendency to the strength, although the maximum peak of elongation appears at 45mo1%Al.
