Annealing behavior of a cast Mg-Gd-Y-Zr alloy with necklace fine grains developed under hot deformation

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

卷:688

Article

Yang, Yi¹  Yang, Xuyue^1,2,3  Xiao, Zhenyu¹  Zhang, Duxiu¹  Wang, Jun⁴  Sakai, Taku⁵ 

[1] Cent S Univ, Educ Key Lab Nonferrous Met Mat Sci & Engn, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China

[2] Cent S Univ, Nonferrous Met Oriented Adv Struct Mat, Changsha 410083, Hunan, Peoples R China

[3] Cent S Univ, Mfg Cooperat Innovat Ctr, Changsha 410083, Hunan, Peoples R China

[4] Deakin Univ, Inst Frontier Mat, Geelong, Vic 3216, Australia

[5] Univ Electrocommun, UEC Tokyo, Chofu, Tokyo 1828585, Japan

关键词: Mg-Gd-Y-Zr alloy;    New fine grains (NFGs);    Hot deformation;    Annealing;    Grain growth;    Texture;   

DOI  :  10.1016/j.msea.2017.02.008

来源: Elsevier

【 摘 要 】

The microstructure and texture development of a cast Mg-Gd-Y-Zr alloy during hot deformation and subsequent annealing were investigated by optical microscopy (OM) and electron backscattered diffraction (EBSD) technology. Initial microstructures with partially and fully developed new fine grains (NFGs), separately attended by continuous or interrupted hot forging, were various mixed grain structures composed of NFGs in necklace and retained coarse grains. It is shown that, during annealing, the development of grain size can be divided into three stages: i.e. an incubation of grain growth, a rapid coarsening and a normal grain growth. After a long time annealing of over 10(4) ks at 693 K, the average grain size for samples continuous compressed to epsilon=1.2 and those interrupted compressed to epsilon=1.6 were close. Moreover, orientations of such strain -induced fine grains were relatively randomly distributed, leading to a weakened basal texture, while the basal plane of retained coarse grains were perpendicular to the forging direction. Such texture even became weaker during subsequent annealing. The results show that the development of necklace NFGs during hot deformation can be effective for homogeneous grain refinement under subsequent annealing.

【 授权许可】

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