大塑性变形制备超细晶铝锂合金的组织及力学性能研究进展

Overview on the microstructure and mechanical properties of ultrafine-grained Al-Li alloys produced by severe plastic deformation

摘要:

近年来,围绕超细晶铝锂合金的制备及其性能提升方面开展了许多研究。本文综述了大塑性变形工艺制备超细晶铝锂合金的显微组织及其力学性能,分析了大塑性变形过程中铝锂合金的组织演变及其影响因素。铝锂合金的强化机制主要是基于析出强化,结合大塑性变形得到的超细晶粒组织可以显著提高强度和塑性,并得到优异的超塑性。表明大塑性变形加工铝锂合金,尤其是等通道挤压制备的超细晶铝镁锂合金在超塑性工业具有广阔的发展前景。

Abstract:

In recent years, fabrication of bulk ultrafine-grained (UFG) Al-Li alloys via severe plastic deformation (SPD) techniques has been investigated to improve properties for expanding its applications as structural products. This review reveals microstructure and mechanical properties of Al-Li alloys produced by SPD techniques. It focuses on the microstructure evolution during SPD, with the influence of internal and external factors. The strengthening mechanism of Al-Li alloys mainly based on precipitation hardening is presented. It is demonstrated that UFG Al-Li may attain enhanced strength with relatively good ductility via grain refinement and multiple precipitates. Special attention is given to the superplasticity of UFG Al-Li alloys, especially to the high strain rate superplasticity (HSR SP). It suggests that UFG Al-Mg-Li alloy produced by SPD, particularly by equal-channel angular pressing (ECAP), is a promising candidate material for use in superplastic forming operations.