TA15合金的热变形行为及加工图

研究了TA15合金的热模拟压缩实验。结果表明：变形温度的升高和应变速率的减小使峰值应力和稳态应力显著降低，变形温度会影响进入稳态流动所需变形量。以热模拟压缩实验为基础，建立的加工图表明：TA15合金高温变形时存在2个非稳定区域，一个是变形温度1300K以上和应变速率10．0s^-1以上的区域，另一个是变形温度1200K以下和应变速率0．006s^-1～1．995s^-1之间的区域。同时，建立的TA15合金高温变形时的流动应力模型表征了变形温度、应变速率和变形程度对流动应力的影响，模型的计算精度较高。

Deformation Behavior and Processing Map of High Temperature Deformation of TA15 Alloy

The isothermal compression of TA 15 alloy has been carried out at a Thermecmaster-Z simulator. The experimental results show that the peak stress and steady stress decrease greatly with increasing of deformation temperature and decreasing of strain rate, and that the deformation temperature will affect the threshold strain to transmit the steady deformation. According to the experimental results, the obtained processing map presents two unsteady zones of high temperature deformation of TA 15 alloy, including the zone above 1300 K of deformation temperature and 10.0 s^-1 of strain rate and another zone below 1200 K of deformation temperature and 0.006 s^-1- 1.995 s^-1 of strain rates. Meanwhile, the present constitutive equation represents the effect of deformation temperature, strain rate and strain on flow stress in high temperature deformation of TA15 alloy. The calculated results of flow stress are in good agreement with the experimental results in high temperature deformation of TA 15 alloy.