β21S钛合金高温变形行为研究

Hot Deformation Behavior of β21S Alloy at Elevated Temperature

在Gleeble-1500热模拟试验机上对β21S钛合金进行了高温恒应变速率压缩实验，研究其在变形温度为750～1100℃，应变速率为0．01～1s^-1条件下的流变应力及微观组织变化规律，计算了变形激活能及应力指数，并给出了流变应力的计算模型。结果表明：合金的流变应力随应变速率的增大而增大，在恒应变速率下，其应力水平随温度的升高而降低；在较低温度和高应变速率变形时，合金仅发生回复现象，随着温度的升高和应变速率的降低，有部分再结晶发生且再结晶程度逐渐增大；计算得出实验条件下的变形激活能和应力指数分别为211．04kJ／mol和4．0129。

Hot compression tests of β21S alloy were performed on Gleeble-1500 tester at strain rates ranged in 0.01-1s^-1 and deformation temperature 750-1100℃. The effect of deformation conditions on flow stress and microstructure of the tested alloy was studied. The deformation activation energy and corresponding stress exponent under hot-compression evaluated quantitatively, the model of flow stress was obtained. The results show that the flow stress is obviously affected by strain rate and deformation temperature. The flow stress becomes higher with increase of strain rate at constant temperature, and lower with increase of deformation temperature at constant strain rate. The recovery only occurs at higher strain rate and on lower temperature, par recrystallize occurs and the degree of recrystallize increases with decrease of strain rate and increase of temperature. The deformation activation energy 211.04kJ/mol and corresponding stress exponent 4. 0129 were obtained respectively.