挤压态阻燃钛合金高温变形行为及机理

摘要

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?1500simulator. 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.