Numerical and experimental investigations of the hot stamping process for complex aircraft skin parts composed of TA32 high-temperature titanium alloy using an Arrhenius-type constitutive model

Abstract

A type of simulation model for a hot stamping forming process was developed for TA32 high-temperature titanium alloy to study the fracture of a complex aircraft skin by using the forming limit stress diagram (FLSD) as a tool to evaluate the formability. After derivation, the theoretical FLSD of TA32 in the hot forming process is strain rate-dependent and temperature-dependent, which is understood from the constitutive relationship of an Arrhenius-type model. Different stress states were used in this study to evaluate the quality of forming via FLSDs. The results show that the materials develop a resistance to fractures in response to an increase in temperature and a decrease in the formation speed. The predicted results also show that the shape of the blank is an important factor that affects part forming. Tests were performed on the TA32 high-temperature titanium alloy to investigate the effects of the processing parameters and the blank shapes. Several indicators were used to assess forming with respect to the thickness distributions in the safe and dangerous areas by comparing the results of the simulations and experiments. Finally, tensile tests under different states were used to indicate that the experimental and simulation results meet practical engineering requirements.