铸造高铌TiAl合金的热变形能力研究

Hot Deformability of Cast High Nb Containing TiAl Alloy

摘要:

在Gleeble-1500热模拟试验机上对高铌TiAl合金进行等温热压缩试验，研究其热压缩变形的流变应力行为。压缩试验的形变温度为900~1250 ℃，形变速率为5×10-4~1 s-1，工程压缩应变为50%和80%。用Zenner-Hollomon参数的指数函数能较好地描述该合金高温变形时的流变应力行为；所获得的峰值应力热变形方程为σp=197.6ln{(Z/9.59×1015)0.285+[(Z/9.59×1015)0.570+1]1/2}，其变形激活能为(497±49) kJ/mol。本研究还给出了

Abstract:

The hot compressive deformation behaviour of high Nb containing TiAl alloy was investigated in the temperature range of 900~1250 ℃, at the strain rate range of 5×10-4 ~1 s-1 and the engineering strain range of 50%~80% on Gleeble-1500 hot simulator. The flow stress behaviour of high Nb containing TiAl alloy can be represented by a Zener-Hollomon parameter in the exponent style equation. The regressed expression is σp=197.6ln{(Z/9.59×1015)0.285+(Z/9.59×1015)0.570+1}1/2}. The hot deformation activation energy of high Nb containing TiAl alloy during hot deformation is (497±49) kJ/mol. The hot deformability map of cast high Nb containing TiAl alloy was given in this paper.