Ti3Al基合金高温变形行为及其流动应力模型

摘要

The hot compression tests of Ti3 A1 based alloy were carried out in the temperature range of 950-1350 ℃ and strain rate range of 0. 001-10.0 s^-1 up to a height reduction of 70% using a Thermermastor-Z simulator. The flow stress-strain curves were plotted using hot compression experimental data, and the high temperature deformation behavior of Ti3A1 based alloy was investigated, and the flow stress model of TiaAl based alloy was constructed by adopting stepwise regression method. The results show that flow stresses of Ti3 A1 based alloy increase with increasing strain rates and decreasing tempera-tures. Error analysis shows that flow stress model can exactly predict flow stresses of Ti3 A1 based alloy in different deforma-tion conditions and can be applied in the design of the hot working process.%在Thermecmastor—Z型热模拟试验机上对TbAl基合金进行等温恒应变速率压缩实验，实验选取的变形温度范围为950～1350℃，应变速率范围为0．001～10S～，高度压下量为70％。利用实验数据绘制出流动应力-应变曲线，研究了Ti3A1基合金的高温变形行为，并运用逐步回归方法构建出该合金的流动应力模型。结果表明，Ti3Al基合金的流动应力随着应变速率的增加而升高，随温度的升高而降低。误差分析表明，该流动应力模型具有较高的精度，可用于指导TbAl基合金热加工工艺的制定。