淬火态Al-Zn-Mg-Cu合金中位错环的形成机理研究  

Formation mechanisms of dislocation loops in a quenched Al-Zn-Mg-Cu alloy

作　　者：宋淼[1] 齐东卿 杜奎[1] 叶恒强[1] SONG Miao;QI Dong-qing;DU Kui;YE Heng-qiang(Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang Liaoning 110016,China)

机构地区：[1]中国科学院金属研究所沈阳材料科学国家研究中心,辽宁沈阳110016

出　　处：《电子显微学报》2020年第6期650-655,共6页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.91960202);辽宁省-沈阳材料科学国家研究中心联合研发基金(No.2019JH3/30100020).

摘　　要：采用透射电子显微镜和原位拉伸实验,研究了淬火态Al-Zn-Mg-Cu合金中三种不同组态的位错环及其形成机理。包括因Al3Zr析出相颗粒与Al基体晶格失配及热膨胀系数差异在Al3Zr颗粒周围形成的位错环;蜷线位错分解形成的位错环;以及因微区成分不均匀或局部缺陷导致的滑移带前端位错绕过或交滑移形成的位错环。研究表明,通过对纳米析出相在Al基体中微观组态的控制和高温淬火处理,可以调控Al合金中位错环的尺寸和三维空间分布。In this study, configurations and formation mechanisms of three types of dislocation loops in a quenched Al-Zn-Mg-Cu alloy were investigated by employing transmission electron microscopy and in situ tension experiment. The three kinds of dislocation loops are: the dislocation loops around the coherent Al3Zr precipitates, which induced by differences of lattice mismatch and thermal expansion coefficient between Al3Zr and Al matrix, the dislocation loops induced by decomposition of helical dislocations, and the dislocation loops in the front end of slip bands induced by bypass or cross-slip of dislocations under the effect of composition segregation or defects. The experimental results reveal the possibility of tuning the distribution and size of dislocation loops in Al alloy by controlling the coherent precipitates and quenching process, and thus improving material properties.

关 键 词：铝合金 AL3ZR 位错环 透射电子显微镜 

分 类 号：TB3[一般工业技术—材料科学与工程] TG146[金属学及工艺—金属材料]