In this paper,the diversity of complicated dendrite microstructure and its evolution behavior during solidification in different magnesium alloys under various processing conditions were illustrated using synchrotron X-ray imaging technique.A variety of dendritic morphologies and branching structures were revealed,i.e.,sixfold plate-like symmetric structure in Mg-Al-based structure,12-branch structure in Mg-Zn-based alloys and 18-branch structure in Mg-Sn-and Mg-Ca-based alloys as well as seaweed like hyper-branched structure in Mg-38wt％Zn alloy.In addition,a dendrite morphology and orientation transition with increasing addition of Zn content were also observed in Mg-Zn alloy,with dendrite growth pattern transform from ani-sotropy (low Zn addition) with sixfold symmetric snow-flake structure to relative isotropy (intermediate Zn addition) where seaweed morphology presented and then back to anisotropy (high Zn addition) when only 12 branches with preferred ＜ 11(2) 1 ＞ orientations were observed.The phase-field model representing the typical dendritic morphologies and branching structures under various conditions was also depicted and discussed.Further,the two-dimensional (2D) real-time dendrite growth dynamics in different Mg-based alloys captured using synchrotron X-ray radiography for unveiling the originate of the α-Mg dendrite was reviewed.Following this,the four-dimensional (3D + time) synchrotron X-ray tomographic in situ observation of dendritic morphology evolution indicating the formation mechanism of the diverse dendritic morphology dur-ing Mg-Sn-and Mg-Zn-based alloys was also summarized.Finally,the future study on exploring the complicated dendritic morphologies and their origination during solidification of Mg-based alloys is prospected.

Yanan Wang;Sansan Shuai;Chenglin Huang;Tao Jing;Chaoyue Chen;Tao Hu;Jiang Wang;Zhongming Ren

State Key Laboratory of Advanced Special Steels,School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;School of Materials,Tsinghua University,Beijing 10084,China

金属学报（英文版）

[1]Yanan Wang;Sansan Shuai;Chenglin Huang;Tao Jing;Chaoyue Chen;Tao Hu;Jiang Wang;Zhongming Ren-.Revealing the Diversity of Dendritic Morphology Evolution During Solidification of Magnesium Alloys using Synchrotron X-ray Imaging:A Review)[J].金属学报（英文版）,2022(02):177-200

38wt,sotropy

Revealing,Diversity,Dendritic,Morphology,Evolution,During,Solidification,Magnesium,Alloys,using,Synchrotron,ray,Imaging,Review,In,this,paper,diversity,complicated,dendrite,microstructure,its,evolution,behavior,during,solidification,different,magnesium,alloys,under,various,processing,conditions,were,illustrated,synchrotron,imaging,technique,variety,dendritic,morphologies,branching,structures,revealed,sixfold,plate,like,symmetric,Mg,Sn,well,seaweed,hyper,branched,addition,morphology,transition,increasing,content,also,observed,growth,pattern,transform,from,snow,flake,relative,intermediate,where,presented,then,back,anisotropy,high,when,only,branches,preferred,orientations,phase,field,model,representing,typical,was,depicted,discussed,Further,two,dimensional,2D,real,dynamics,captured,radiography,unveiling,originate,reviewed,Following,four,tomographic,situ,observation,indicating,formation,mechanism,diverse,summarized,Finally,future,study,exploring,their,origination,prospected

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