锻态TB6钛合金热变形行为及组织演变

在THERMECMASTER-Z型热模拟试验机上,对锻态TB6钛合金在真应变为0.92、变形温度为800℃～1150℃、应变速率为0.001s-1～1s-1的条件下进行等温恒应变速率压缩试验,分析合金在β单相区条件下的热变形特点,并观察金相组织。结果表明,应变速率对合金流动应力的影响较显著;而变形温度对合金流动应力的影响在较高应变速率时较大,在较低应变速率时较小。动态再结晶晶粒尺寸和动态再结晶体积分数,随温度的升高而增大,随应变速率的增大而减小。从晶粒细化和动态再结晶组织均匀性考虑,当真应变为0.92时,变形温度选择在950℃～1050℃之间,应变速率选择在0.01s-1为宜。

Investigation on the hot temperature deformation behavior and microstructure evolution of forged titanium alloy TB6

Isothermal constant strain rate compression tests for forged TB6 alloy at 800℃～1150℃ with strain rate 0.001s-1～1s-1 were conducted up to a true strain of 0.92 adopting THERMECMASTER-Z hot temperature simulator.The characteristics of hot deformation and microstructure of the alloy were studied at the β phase field.The results show that the strain rate affects flow stress obviously;while the effect of deformation temperature on flow stress is more obvious at high strain rate than that at low strain rate.The grain size and volume fraction of dynamic recrystallization increase with the increase of temperature,whereas decrease with the increase of strain rate.According to the effect of grain refinement and uniformity in the dynamic recrystallization microstructure,the deformation temperature 950℃～1050℃ and the strain rate 0.01s-1 are preferable for hot deformation.