γ-TiAl合金高温塑形变形力学行为及本构模型

Flow Behavior and Constitutive Models of γ-TiAl Alloys Deformed at Elevated Temperature

摘要:

轻质高强γ-TiAl合金是航空发动机关键结构件减重的首选材料。本文概括总结了γ-TiAl合金的高温压缩变形力学行为及本构模型，重点分析了变形工艺参数、变形历史和预热处理、元素、原始组织对γ-TiAl合金高温压缩变形力学行为的影响。本文概括总结了三种本构模型：经验型本构模型、不同软化机制下的本构模型和耦合变形机理的微观模型，并对Arrhenius模型和H-S模型进行了详细分析。同时，对不同软化机制下的本构模型和耦合变形机理的模型进行了总结分析。最后指出，γ-TiAl合金高温压缩变形力学行为的未来研究重点是建立耦合多相协调性高温变形机理的本构模型。

Abstract:

γ-TiAl alloys with low density and high stiffness are preferred structural materials for weight saving of aircraft engines. The present paper deeply reviews flow behavior and constitutive equations of γ-TiAl alloys compressed at elevated temperature. Deformation processing parameters, deformation history and adjusted preheating treatment, chemical compositions and initial microstructures are main factors that determine flow behavior of γ-TiAl alloys compressed at elevated temperature. The constitutive models describing flow stress-strain curves are segmented into genres, such as empirical models, model coupled with different softening mechanisms and models about deformation mechanisms. Arrhenius model and H-S model are deeply discussed. Also, constitutive model including softening mechanism and models involving deformation mechanisms are summarized and analyzed. It predicts that emphasis on further research in γ-TiAl alloys is to establish constitutive models involving multiphase coordinating deformation mechanisms.