Fracture criterion in hot compression of Ti60 titanium alloy by high-speed photography

A novel high-speed photography was introduced to determine the critical fracture strain of Ti60 high-temperature titanium alloy during hot compression deformation. This method can precisely capture the nucleation site and propagation process of cracking by two high-speed cameras fixed on opposite sides of the specimens, and thus it is efficient to determine the critical fracture strain in hot deformation processes. Based on Oh criterion, a new hot deformation fracture criterion considering strain rate and temperature effects was built and can be modeled as the function of Zener-Holloman parameter. By combining the DEFORM-3D simulation software and FORTRAN language, fracture initiation in the upsetting of large size Ti60 ingot can be precisely predicted, which shows that the proposed prediction model is effective and practicable.