Simultaneous multiscale measurements on dynamic deformation of a magnesium alloy with synchrotron x-ray imaging and diffraction

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:701

Article

Lu, L.^1,2,3  Sun, T.⁴  Fezzaa, K.⁴  Gong, X. L.¹  Luo, S. N.^2,3 

[1] Univ Sci & Technol China, Dept Modern Mech, CAS Key Lab Mech Behav & Design Mat, Hefei 230027, Anhui, Peoples R China

[2] Southwest Jiaotong Univ, Minist Educ, Key Lab Adv Technol Mat, Chengdu 610031, Sichuan, Peoples R China

[3] Peac Inst Multiscale Sci, Chengdu 610031, Sichuan, Peoples R China

[4] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA

关键词: Multiscale measurements;    Digital image correlation;    X-ray diffraction;    Twinning;    Dislocation;   

DOI  :  10.1016/j.msea.2017.06.073

来源: Elsevier

【 摘 要 】

Dynamic split Hopkinson pressure bar experiments with in situ synchrotron x-ray imaging and diffraction are conducted on a rolled magnesium alloy at high strain rates of similar to 5500 s(-1). High speed multiscale measurements including stress-strain curves (macroscale), strain fields (mesoscale), and diffraction patterns (microscale) are obtained simultaneously, revealing strong anisotropy in deformation across different length scales. {10 (1) over bar2} extension twinning induces homogenized strain fields and gives rise to rapid increase in strain hardening rate, while dislocation motion leads to inhomogeneous deformation and a decrease in strain hardening rate. During the early stage of plastic deformation, twinning is dominant in dynamic compression, while dislocation motion prevails in quasi-static loading, manifesting a strain-rate dependence of deformation.

【 授权许可】

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