(中国科学院 金属研究所，沈阳 110016)
摘 要: 在Gleeble-3800热模拟机上对具有原始b转变组织的Ti-24Al-17Nb-0.5Mo合金进行单道次热压缩变形试验，研究变形温度在900~1 130 ℃、应变速率在0.01~40 s−1条件下合金的热变形行为，计算该合金的应变速率敏感因子和变形激活能，确定适合峰值应力的流变应力的方程。结果表明：该合金的真应力—真应变曲线在不同的热变形条件下具有不同的特征；合金热变形的峰值应力随温度的升高而降低，随应变速率的增加而增大，合金在不同变形条件下具有不同的应变速率敏感因子和变形激活能。
关键字: Ti3Al合金；热变形；峰值应力；本构关系
(α2+O+B2) three phases Ti3Al-based alloy
（Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China）
Abstract:The hot compression deformation behaviours of Ti-24Al-17Nb-0.5Mo titanium alloy with original b-transformed microstructure were studied at the temperature range of 900−1 130 ℃ and strain rate of 0.01−40 s−1 by Thermomaster Simulator Machine 3800. The strain rate sensitivity exponent and activation energy were determined, respectively, and the constitutive equation fitting peak stress state was obtained. The results show that the true stress—true train curves have different characteristics under different deformation conditions. The peak stress becomes lower with the increase of deformation temperature at constant strain rate, and increases with the increase of strain rate at constant temperature. The strain rate sensitivity exponent and activation energy vary with the change of different deformation conditions.
Key words: Ti3Al alloy; hot deformation; peak stress; constitutive equation
