(中南大學(xué) 粉末冶金國家重點實驗室， 長沙 410083)
摘 要: 采用包套軋制技術(shù)，在1050℃制備了2.7mm厚的TiAl基合金薄板。金相觀察表明，薄板具有均勻、 細(xì)小的組織，平均晶粒尺寸約為3μm。利用模擬平面應(yīng)變實驗研究了外加包套對TiAl基合金軋制時流變行為的影響，揭示了包套軋制提高TiAl基合金熱加工性能的機理。結(jié)果表明，包套軋制可以降低TiAl基合金變形時的流變應(yīng)力，延緩流變軟化趨勢，降低局部流變系數(shù)，從而提高TiAl基合金的塑性變形能力。
關(guān)鍵字: TiAl基合金； 板材； 包套軋制； 塑性變形
HE Shuang-zhen， LIU Yong， HE Yue-hui
（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
