Damage and fracture mechanism of as-cast ti40 titanium alloy during hot compression

The damage and fracture behavior was researched in hot compression of as-cast Ti40 titanium alloy with single β phase. The main fracture modes consist of 45° shear fracture, inner cracking and longitudinal cracking on free-surface, which occur at 850°C/10s-1, 900~950°C/10s^-1 and other deformation conditions respectively. Moreover, 45° transgranular cracking is the combination result of adiabatic shear bands due to local temperature rise and shear stress, the inner intergranular cracking is induced by the microvoids near the adiabatic shear bands propagted along grain boundry under shear stress, the surface longitudinal intergranular cracking is caused by the vaporization of oxide and function of hoop tensile stress. In addition, the material undergoes the complex fracture which has to be avoided or decreased in hot processing for obtaining satisfactory properties.