中文摘要：

铸态TiAl合金经过脉冲电流处理后,其显微组织由粗大的全片层组织转变成为细小的魏氏体组织,且室温拉伸塑性明显提高。在魏氏体组织中,片层的平均厚度很小,γ/α2相界面和γ/γ真孪晶界面占的比例很高,这种结构特征有利于提高材料的抗蠕变性能。魏氏体组织的形成与脉冲电流处理中的快速升温过程密切相关。

英文摘要：

　Instead of conventional grain refinement treatments for TiAl alloys,a high density electric current pulse（ECP）treatment was applied to refine the coarse fully lamellar structure.Widmansttten microstructure with multi-orientational refined lamellar sub-colony has been achieved in the TiAl alloy.And the tensile ductility of the alloy has been improved noticeably.The rapid heating process of the ECP treatment was responsible for the refined Widmansttten microstructure formation.