Effect of grain boundary misorientation on discontinuous precipitation in an AZ91 alloy

Bulletin of materials science

B Alili¹  Z Boumerzoug²  H Azzeddine¹  D Bradai¹  S Abdessameud¹ 

[1] Faculty of Physics, University of Sciences and Technology Houari Boumediene, BP 32 El-Alia, Bab-Ezzouar, Algiers, Algeria$$Faculty of Physics, University of Sciences and Technology Houari Boumediene, BP 32 El-Alia, Bab-Ezzouar, Algiers, AlgeriaFaculty of Physics, University of Sciences and Technology Houari Boumediene, BP 32 El-Alia, Bab-Ezzouar, Algiers, Algeria$$;Department of Metallurgy, University of Biskra, B.P. 145, 07000, Algeria$$Department of Metallurgy, University of Biskra, B.P. 145, 07000, AlgeriaDepartment of Metallurgy, University of Biskra, B.P. 145, 07000, Algeria$$

关键词: AZ91 alloy;    precipitation;    kinetics;    GBCD;    EBSD.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

A scanning electron microscopy (SEM)-based electron backscatter diffraction (EBSD) analysis showed that the discontinuous precipitation (DP) reaction rate was dependent on the geometry of the grain boundary in Mgâ€�??9Alâ€�??1Zn (wt.%) alloys. DP converted a supersaturated solid solution, ð›�?₀ (magnesium (Mg)-rich solid solution), into a two-phase ð›�? + ð›�? aggregate, with ð›�? being a precipitated Mg₁₇Al₁₂ (intermetallic phase) behind a migrating reaction front. The near-special grain boundary was rather inactive, whereas most of the random high-angle boundaries promoted the reaction. Prior deformation (hot rolling to achieve up to 80% thickness reduction) had no effect on the frequency of special-grain boundaries.

【 授权许可】

Unknown