Distinguished roles of static aging and strain aging in the microstructure and creep resistance of Mg-4Y-3.5Nd alloy  

作　　者：Zhirou Zhang Qinghuan Huo Yuxiu Zhang Byung-joo Kim Hiromi Nagaumi Xuyue Yang 

机构地区：[1]School of Materials Science and Engineering,Central South University,Changsha 410083,China [2]Advanced Metals Division,Korea Institute of Materials Science,Changwon 51508,Republic of Korea [3]School of Iron and Steel,Soochow University,Suzhou 215100,China

出　　处：《Journal of Materials Science & Technology》2024年第14期20-40,共21页材料科学技术（英文版）

基　　金：supported by the National Key Research and Development Program of China(Nos.2022YFE0109600 and 2021YFB3701100);the National Natural Science Foundation of China(Nos.51974376 and 52071344);the Natural Science Foundation of Hunan Province(No.2021JJ20063).

摘　　要：This work concerns the distinguished roles of static aging and strain aging in the creep resistance of a hot-rolled Mg-4Y-3.5Nd alloy.The solution-treated sample is named AS while the peak-aged sample ob-tained from static aging at 220℃ is named AA.The strain aging(creep loading)was performed for both AS and AA samples at 220,250 and 280℃,respectively.The results showed that the creep resistance of both samples was closely related to the width of precipitate-free zones(PFZs).Under low stress,the dislocation cross-slip was effectively delayed by the precipitates and the existing PFZs widened slowly in the AA sample,leading to its stronger creep resistance compared to the AS sample.Inversely,under high stress,pyramidal<c+a>slip was more frequently activated,which could not be delayed by the coars-ened precipitates.Consequently,the widening rate of PFZs became fast and the creep resistance became weaker in the AA sample.From the above-mentioned results,this work provides a novel guide for using Mg alloys with rare-earth addition.At the temperature range of 220-280℃,static aging is positive for creep resistance under low stress,while directly performing strain aging without static aging is recom-mended for creep resistance under high stress.

关 键 词：MAGNESIUM MICROSTRUCTURE CREEP PRECIPITATION Dislocation slip 

分 类 号：TG139[一般工业技术—材料科学与工程]