Tensile Fracture Behavior of a Cast Gamma-Titanium Aluminide

ABSTRACTThe fracture behavior of a cast gamma-titanium-aluminide alloy (Ti-49.5A1–2.5Nb-l. 1Mn) during deformation processing was investigated using hot-tension testing and isothermal-forging experiments. In uniaxial tension, fracture ductility increased with an increase in the test temperature and a decrease in the imposed strain rate. During open-die forging of this alloy under isothermal conditions, tensile stresses generated due to frictional effects and the associated inhomogeneous plastic deformation led to free-surface fracture via intergranular cracking. The failure observations under these two deformation modes were correlated successfully using a tensile-damage criterion.