置氢Ti-55钛合金在脉冲电流作用下的变形行为

Deformation behavior of hydrogenated Ti-55 titanium alloy under pulse current conditions

通过热氢处理和电辅助成形工艺相结合来改善钛合金的热加工性能。以Ti-55钛合金为研究对象,通过电塑性拉伸、断口分析、金相观察等方法,研究置氢Ti-55钛合金在脉冲电流作用下的变形行为。研究发现,在施加脉冲电流条件下,随氢含量的增加,置氢合金的伸长率先增加后降低,峰值应力逐渐降低后稍有增加,其中置氢0. 4%合金伸长率最大,为28. 2%,峰值应力最小,为605. 8 MPa,与原始合金相比,其伸长率提高105. 8%,峰值应力降低27. 3%;置氢0. 4%合金中β相体积分数显著增加,有利于变形时晶界和相界的流动,因此表现出较高的伸长率和较低的流动应力。

By combining the thermo-hydrogen process with electrically assisted forming process,the hot-working property of titanium alloy was improved. The Ti-55 titanium alloy was taken as the research object,the deformation behavior of hydrogenated Ti-55 titanium alloy under pulse current conditions was investigated by electroplastic tension,fracture analysis and metallographic observation. The research show that the elongation of the hydrogenated alloy increases firstly and then decreases with the increase of hydrogen content under the pulse current condition. Meanwhile,the peak stress decreases gradually and then increases slightly. The elongation of the hydrogenated alloy with 0. 4 % H reaches the maximum value of 28. 2 % and the peak stress reaches the minimum value of605. 8 MPa. Its elongation is improved by 105. 8 % and its peak stress is reduced by 27. 3 % compared with those of as-received alloy under pulse current. The volume fraction of β phase in the hydrogenated alloy with 0. 4 % H increases significantly,which is beneficial to the flow of grain boundary and phase boundary during deformation. Therefore,it shows a higher elongation and lower flow stress.