Ti-6Al-4V钛合金薄板应力松弛行为研究

The multiple sets of stress relaxation crossover tests of the Ti-6Al-4V titanium alloy ultrathin sheet with the different temperatures (650℃, 700℃ and 750℃) and the different pre-strain (2%, 4% and 16%) are carried out. The effects of temperature and pre-strain on the stress relaxation resistance of Ti-6Al-4V titanium alloy and the stress relaxation behavior at high temperature are investigated. Based on the experimental data,the stress relaxation curve fitting of Ti-6Al-4V titanium alloy is carried out with a more accurate four-order delay function. The results of the four-time delay function prediction are in good agreement with the experimental data,and the fitting accuracy is as high as 99.724%. Based on the experimental data,the relationship between the short-term creep strain rate and stress at high temperature is further derived. Finally,based on the Arrhenius constitutive model,the high-temperature short-time creep constitutive equation of Ti-6Al-4V titanium alloy ultrathin sheet is established,which laid a foundation for subsequent hot sizing process formulation and numerical simulation.