中文摘要：

利用热模拟试验机对铸态Ti40合金在950～1100℃、0.001～1.0s-1条件下进行热压缩试验,研究了应变速率对该合金流动应力和变形组织的影响。结果表明,流动应力随应变速率的增大而增大,不同温度和应变速率的真应力-真应变曲线呈稳态流动型。温度越低,发生动态再结晶的应变速率越小,且动态再结晶晶粒的体积分数和平均晶粒尺寸均随应变速率的减小而增大。在实验热力参数下的动态再结晶程度比较低,最大的体积分数在20%左右,再结晶晶粒的平均尺寸为19.2～47.0μm。从降低能耗和提高加工性能等角度考虑,在950～1000℃,应变速率以小于0.1s-1为宜;在1050℃附近,应变速率以小于1.0s-1为宜;在1100℃附近,应变速率以1.0～0.001s-1较适宜。

英文摘要：

The hot compression test of as-cast Ti40 alloy was carried out at the temperature range of 950 ℃～1100 ℃ and the strain rate range of 0.001 s-1～1.0 s-1 by a hot working simulator,and the effects of strain rate on flow stress and deformed microstructure of the alloy were studied.The results show that the flow stress increases with the increase of strain rate,and the true stress-true strain curves at different temperature and strain rates are stable-state.The lower the temperature,the lower the strain rate of dynamic recrystallization beginning.The volume fraction and average size of dynamic recrystallization grain increase with the decrease of strain rate.The degree of dynamic recrystallization is lower,and the maximum volume fraction is only about 20%.The average size of dynamic recrystallization grain is between 19.2 μm and 47.0 μm.Considering reducing energy consumption,improving workability and other aspects,the preferable strain rate should be below 0.1 s-1 at 950 ℃～1000 ℃.The preferable strain rate should be below 1.0 s-1 at 1050 ℃.The preferable strain rate should be at the range of 1.0 s-1 ～0.001 s-1 at 1100 ℃.