Mg-Li-Al-Gd合金时效析出行为的电子显微研究  

Electron Microscopic Study of Ageing Precipitation Behavior in Mg-Li-Al-Gd Alloys

作　　者：郅露寒 刘林林 刘翠秀 段志萌 ZHI Luhan;LIU Linlin;LIU Cuixiu;DUAN Zhimeng(School of Materials Science and Engineering,Beijing University of Technology,Beijing,China,100124)

机构地区：[1]北京工业大学材料科学与工程学院,北京100124

出　　处：《有色金属设计》2025年第1期122-126,共5页Nonferrous Metals Design

基　　金：北京市自然科学基金资助项目(No.2212024)。

摘　　要：利用HAADF-STEM、EDS等多种电子显微表征技术,对固溶和时效态的Mg-30Li-2Al-0.2Gd(LAG3020)合金进行了显微结构表征。结果显示,铸态LAG3020合金经过固溶处理后,在基体中观察到大量平均直径约为100nm的片状(Mg,Li)3Al相,这些析出相的形成是固溶合金具有最佳力学性能的来源。随后时效处理过程中,基体中(Mg,Li)3Al相的形貌逐渐转变成球形;同时,晶界处也析出了大量平均直径约500nm的球状(Mg,Li)3Al相,伴随着晶界附近和基体中α-Mg相的析出;这些因素导致合金在时效过程中逐渐软化。Using multiple electron microscopy characterization techniques such as HAADF-STEM and EDS,the microstructure of the solution-treated and aged states of Mg-30Li-2Al-0.2Gd(LAG3020)alloy was characterized.Results show that after solution treatment,numerous plate-like(Mg,Li)3Al phases with an average diameter of approximately 100 nm were observed in the matrix of the as-cast LAG3020 alloy.The formation of these precipitated phases contributes to the solution-treated alloy’s optimal mechanical properties.During subsequent aging,the morphology of the(Mg,Li)3Al phase in the matrix gradually transforms into a spherical shape.Simultaneously,numerous spherical(Mg,Li)3Al phases with an average diameter of approximately 500 nm precipitate at the grain boundaries,accompanied by the precipitation ofα-Mg phases near the grain boundaries and within the matrix.These factors result in the gradual softening of the alloy during the aging process.

关 键 词：MG-LI-AL合金 时效析出 时效软化 相变 

分 类 号：TG146.22[一般工业技术—材料科学与工程]