锻压技术

镁锂合金多向压缩的组织演变及力学性能

英文标题：Microstructure evolution and mechanical properties on Mg-Li alloy in multiaxial compression

单位：1. 西安航空学院材料工程学院 2. 航空工业西安飞机工业(集团)有限责任公司

分类号：TG302

出版年,卷(期):页码：2022,47(9):250-255

摘要：

利用OM、SEM和XRD表征了室温多向压缩镁锂合金的显微组织，分析了多向压缩变形过程中的组织演变及力学性能变化。结果表明：镁锂合金由α-Mg、β-Li、纤维状Mg17Al12、颗粒状MgLiAl2和球形AlLi 这5相组成。压缩时β-Li相首先产生滑移并形成位错塞积，晶界被突破后逐渐消失，累计应变的增长触发α-Mg相滑移面开动，α-Mg相和β-Li相在相界面处不断融合，甚至融为一体。Mg17Al12相被分割为短纤维或小颗粒，MgLiAl2相逐渐失去平直排列，最终均匀分布在β-Li相内部。硬度随着变形程度的增大而升高，初期和后期比较显著，中间阶段较为平缓，累积应变达到15.8时，硬度提升了19.8%。镁锂合金形变强化的同时其伸长率也大幅提高，累积应变为6.22时，合金的抗拉强度提高了35%，伸长率提高了82%。

The microstructure of multiaxial compression for Mg-Li alloy at room temperature was characterized by OM, SEM and XRD, and the evolution of microstructure and the change of mechanical properties during multiaxial compression deformation process were analyzed. The results show that Mg-Li alloy is composed of five phases of α-Mg, β-Li, fibrous Mg17Al12, granular MgLiAl2 and spherical AlLi. During compression, β-Li phase first produces slip and forms dislocation plugging, and the grain boundary is broken through and gradually disappears, the increasing of cumulative strain triggers the activation of α-Mg phase slip surface, and α-Mg phase and β-Li phase are continuously fused at the phase interface, even integrated. Mg17Al12 phase is divided into short fibers or small particles, and MgLiAl2 phase gradually loses its straight arrangement and is finally evenly distributed in β-Li phase. The hardness increases with the increasing of deformation degree, which is significant in the initial and later stages, and gentle in the middle stage. When the cumulative strain reaches 15.8, the hardness increases by 19.8%. The elongation of Mg-Li alloy can also be greatly improved while the deformation is strengthened. When the cumulative strain is 6.22, the tensile strength of the alloy is increased by 35%, and the elongation is increased by 82%.

基金项目：

陕西省自然科学基础研究计划资助项目（2019JM-247）；西安航空学院校级科研基金项目（2019KY1229）；大学生创新创业训练计划项目（S202011736005）

朱嵩琦（1988-），男，学士 E-mail：742791330@qq.com 通信作者：张金龙（1976-），男，博士，教授 E-mail：zjl24931@163.com

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