Investigation on the hot formability of TA15 titanium alloy sheet

摘要

The hot formability of TA15 titanium alloy sheet was studied experimentally and theoretically. The hot uniaxial tensile tests were conducted for further investigation on hot formability. Based on the finite element models in different thermal conditions, the punch displacement-force curves were compared to test data to investigate the influence of sheet temperature distribution on limit strain. The simulation results indicated that the hot punch was essential for keeping the temperature of sheet center region. Meanwhile, the non-uniform sheet temperature distribution that the temperature of central sheet was higher than the one at sheet edge, was positive for making the damage occur at an appropriate region due to the good deformability of central sheet with higher temperature. The theoretical FLCs of TA15 titanium alloy sheet were predicted by introducing Hill48 yield criterion and temperature path into M-K model. The results proved that the monotonic decreasing temperature path had no effect on sheet formability, and the Nakazima test results depended on the final temperature of region at where the fracture or necking occurred. The comparison results also indicated that the test data agreed well with the theoretical FLC at 810 ℃.