平面应力条件下TA15钛合金超塑性

Research on the superplastic deformation of TA15 Titanium alloy under plane stress

采用受平面应力变形的锥形件和盒形件的气压胀形实验,研究TA15钛合金在不同温度的变形能力,通过显微组织观察和力学性能测试,分析变形过程中的组织变化和性能变化。结果表明,940℃时,材料达到最佳超塑性,锥形件最大高度为94.4mm,最小壁厚为0.1mm,且盒形件的力学性能较原始板材略有提高。在温度940℃和980℃变形时均有β相析出,且随着应变的增大,α相体积分数先减少后增加,组织粗化是导致材料失效的主要原因。

The superplastic forming process of taper and box-shaped components of TA15 titanium alloy using gas bulging method at different temperature was investigated. The microstructure and tensile property were analyzed. Results indicate that the best superplasticity was obtained at 940℃, and the tensile property of box structure is a little higher than the original sheet. The phase appeared at 940℃ and 980℃, and the volume fraction of α phase decreased first and then increased with the increase of strain. Material fracture is mainly due to the formation of coarse microstructure.