变形处理对Mg-Li合金显微组织演变和力学性能的影响

Effect of deformation processing on microstructure evolution and mechanical properties of Mg−Li alloys:A review

镁锂合金具有较高的比强度和比刚度、优秀的电磁屏蔽效应和阻尼性能等优点,是目前最轻的金属结构材料,在自动化、航空、交通运输、医疗等领域有广泛的应用前景。但是,和其他金属结构材料相比,镁锂合金的强度仍然偏低,需要对镁锂合金进行合金化或者变形处理来提高力学性能。总结了各类变形处理镁锂合金的研究现状,讨论了常规变形加工和剧烈塑性变形加工对镁锂合金显微组织和力学性能的影响,并总结了变形加工过程中形变量和温度对显微组织和力学性能的影响,以及镁锂合金的几种晶粒细化机制,阐述了镁锂合金在工业应用中遇到的问题。晶粒细化和加工硬化目前仍然是提高镁锂合金性能的主要手段。强调了几种变形和结构设计(异质材料),这将有助于镁锂合金的创新工作,从而得到高强度镁锂合金。

As the lightest structural metal,Mg-Li alloys,possessing the advantages of high specific strength,high specific stiffness,good electromagnetic shielding,and damping properties,have a bright application prospect in automotive,aerospace,transportation,medical and other fields.However,the strength of Mg-Li alloys is lower when compared to other structural metals,which requires alloying or deformation treatment to enhance mechanical properties.The research progress of deformation processing of Mg-Li alloys is summarized,including the effect of conventional plastic deformation and severe plastic deformation on the microstructure and mechanical properties of Mg-Li alloys,the effect of strain and temperature in the deformation process on their microstructure and mechanical properties,and several grain refinement mechanisms of Mg-Li alloys.The problems encountered during the industrial application of Mg-Li alloys are discussed.Grain refinement and enhanced work hardening are still the primary means to improve the comprehensive performance.Several structural design strategies(heterogeneous structured materials)are highlightened,which will be helpful for the guidance of future innovations for Mg-Li alloys to reach high strength.