Influence of Nd or Ca addition on the dislocation activity and texture changes of Mg-Zn alloy sheets under uniaxial tensile loading

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

卷:761

Article

Ha, Changwan¹  Bohlen, Jan¹  Yi, Sangbong¹  Zhou, Xiaohua²  Brokmeier, Heinz-Guenter²  Schell, Norbert³  Letzig, Dietmar¹  Kainer, Karl Ulrich¹ 

[1] Helmholtz Zentrum Geesthacht, Magnesium Innovat Ctr MagiC, Max Planck Str 1, D-21502 Geesthacht, Germany

[2] Tech Univ Clausthal, Inst Mat Sci & Engn IWW, Agr Str 6, D-38678 Clausthal Zellerfeld, Germany

[3] Helmholtz Zentrum Geesthacht, DESY, HZG Outstn, Notkestr 85, D-22607 Hamburg, Germany

关键词: Magnesium;    Microstructure;    Texture;    Dislocation;    Synchrotron;    EBSD;   

DOI  :  10.1016/j.msea.2019.138053

来源: Elsevier

【 摘 要 】

In situ hard X-ray diffraction experiments were carried out to investigate the dislocation slip activity of Mg-1 wt. % Zn-based alloys containing Nd or Ca during tensile loading. Diffraction patterns collected during tensile loading at 3 temperatures were analyzed using a convolutional multiple whole profile fitting procedure. High activation of nonbasal < a > and pyramidal < c +a > dislocations was found in the Nd- and Ca-containing alloys. The microstructure evolution after 10% deformation was examined by complementary EBSD measurements. The microstructure evolution was related to the differences in the initial texture and active deformation modes, according to the alloying and temperature. In-grain misorientation axes analysis obtained from the EBSD measurements confirms that the addition of Nd or Ca contributes to the higher activity of prismatic < a > slip. The high activity of prismatic < a > slip leads to a broadening of the basal poles perpendicular to the loading direction and a strengthening of the <10<(1)over bar>0> pole along the loading direction. The overall dislocation density evolution at elevated temperatures is controlled by dynamic recovery and dynamic recrystallization. These thermally activated mechanisms are retarded in the Nd- or Ca-containing alloys.

【 授权许可】

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