Understanding activation and growth of twin variants in polycrystalline magnesium under tension and compression:An atomistic study  

作　　者：Huicong Chen Cheng Chen Jun Song Stephen Yue 

机构地区：[1]Department of Mining and Materials Engineering,McGill University,3610 Rue University,Montréal,H3A 0C5,Canada [2]School of Aeronautics,Northwestern Polytechnical University,Xi’an,Shaanxi 710072,China

出　　处：《Journal of Magnesium and Alloys》2024年第12期4923-4936,共14页镁合金学报(英文)

基　　金：financial support from Natural Sciences and Engineering Research Council of Canada(NSERC RGPIN-2023–03628);H.C.also thanks the financial support from China Scholarship Council(201706050149);McGill Engineering Doctoral Award for financial support.

摘　　要：Deformation twinning is known to be important in the acquisition of plasticity for hexagonal close-packed crystal structures,of great implication to the design and development of novel high-strength Mg alloys with enhanced formability.Accurate understanding of deformation twinning necessitates critical mechanistic knowledge of the activation and selection of twins at nanoscale.In this work,considering polycrystalline Mg,we performed comprehensive molecular dynamics simulations to investigate deformation twinning under uniaxial tension and compression loading.An algorithm has been developed and implemented to identify the active twin variants of three operating twin modes during deformation.Sharp contrast between tension and compression loading in terms of twin patterns and twin growth was observed,attributed to difference in twin variant activation and twin-twin interaction under the two loading conditions.Furthermore,the critical role of Schmid factor in twin variant activation and selection has been elucidated,in good agreement with experimental observations.This study contributes critical insights towards advancing our understanding of the complex behaviors of deformation twinning in polycrystalline Mg.

关 键 词：MAGNESIUM Deformation twinning Twin variant Schmid factor Molecular dynamics. 

分 类 号：TG146.22[一般工业技术—材料科学与工程]