挤压态阻燃钛合金高温变形行为及机理

Hot deformation behavior and mechanism of as-extruded burn resistant titanium alloy

通过等温恒应变速率热模拟压缩试验,研究一种挤压态组织的阻燃钛合金在变形温度900~1150℃,应变速率0.001~1 s^(-1)条件下的高温流变应力和组织演变,基于热压试验数据计算变形激活能。结果表明:此种阻燃钛合金流变应力-应变曲线具有应力峰值和流动软化特征,高温变形是扩散控制的过程,软化机制以动态回复为主,但在应变速率较高时会发生局部连续再结晶,而在应变速率较低时晶界运动比较明显。

The hot deformation behavior and structural evolution of a burn resistant titanium alloy were studied on the as-extruded samples in the temperature range of 900-1150℃ and the strain rate range of 0.001-1 s-1 through the Gleeble-1500 simulator. The deformation activation energy was calculated based on simulation data. The results show that the stress-strain curves exhibit an obvious peak followed by a broad flow softening in higher strain rate ranges. Hot deformation of the burn resistant titanium alloy is lattice diffusion controlled, and dynamic reversion is the primary softening mechanism, while a typical continuous recrystallization will occur at the higher strain rates, and grain boundary migration will occur at lower strain rates.