TC4钛合金EB炉扁锭高温压缩变形行为和热加工图

High temperature compression deformation behavior and hot processing map of TC4 titanium alloy slab smelted by electron beam cold bed furnace

采用Gleeble-3500热/力学模拟试验机对电子束冷床炉(EB炉)熔炼的TC4钛合金扁锭进行高温压缩实验,研究了TC4钛合金扁锭在变形量为40%,温度为1023~1173 K,应变速率为0.001~1 s-1的条件下热压缩变形行为。通过使用双曲正弦形式修正的Arrhenius关系来描述TC4钛合金高温压缩变形时最大变形抗力的本构方程,并绘制出TC4钛合金的加工图。结果表明,真应力-应变图可以很好地反映TC4钛合金在不同变形条件下的应力状态,且应力值和实验值有较好相关性。基于Prasad判据得到铸态TC4钛合金的热加工图的最佳变形区间为:变形温度为1023~1173 K,应变速率为0.001~0.002 s^(-1)的区域及变形温度为1073~1160 K,应变速率为0.316~1 s^(-1)的区域。

High temperature compression experiment of TC4 titanium alloy slab smelted by electron beam cold bed furnace was carried out by Gleeble-3500 thermal/mechanical simulation machine, and the high temperature deformation behavior of the TC4 titanium alloy under the conditions of deformation amount of 40%, deformation temperature of 1023-1173 K and stain rate of 0.001-1 s-1, was studied. The modified Arrhenius model was used to describe the constitutive equation of maximum deformation resistance of the TC4 titanium alloy at high temperature compression deformation, and the processing map was drawn. The results show that the true stress-strain diagram can well reflect the stress state of the TC4 titanium alloy under different deformation conditions, and the stress value has good correlation with the experimental value. Based on the Prasad criterion, the optimal deformation parameters of the as-cast TC4 titanium alloy are as follows: the deformation temperature of 1023-1173 K and the strain rate of 0.001-0.002 s^(-1), and the deformation temperature of 1023-1173 K and the strain rate of 0.316-1 s^(-1).