(中南大学 粉末冶金国家重点实验室， 长沙 410083)
摘 要: 采用包套轧制技术，在1050℃制备了2.7mm厚的TiAl基合金薄板。金相观察表明，薄板具有均匀、 细小的组织，平均晶粒尺寸约为3μm。利用模拟平面应变实验研究了外加包套对TiAl基合金轧制时流变行为的影响，揭示了包套轧制提高TiAl基合金热加工性能的机理。结果表明，包套轧制可以降低TiAl基合金变形时的流变应力，延缓流变软化趋势，降低局部流变系数，从而提高TiAl基合金的塑性变形能力。
关键字: TiAl基合金； 板材； 包套轧制； 塑性变形
（State Key Laboratory for Powder Metallurgy，
Central South University， Changsha 410083， P.R.China）
Abstract: A Ti-48Al-2Cr-0.5Mo(mole fraction, %) sheet，with the thickness of 2.7mm，was prepared at 1050℃ by pack rolling. Microstructure of the sheet and the effect of pack on the flow behavior were investigated using optical microscopy and plain-strain compression testing. The experimental results show that，dynamic recrystallization and static recrystallization occur during pack-rolling and following reheat process between two rolling passes，thus，homogenous and refined microstructure with mean size of 3μm is formed. During deformation of packed-TiAl based alloy，the lower flow stress and flow localization parameter are obtained，which lead to the increasing workability of TiAl based alloy at elevated temperature.
Key words: TiAl based alloy; pack rolling; sheet; hot deformation
