Crystallographic account of an ultra-long period stacking ordered phase in an Mg88Co5Y7 alloy

JOURNAL OF ALLOYS AND COMPOUNDS

卷:693

Article

Jin, Q. Q.^1,2  Shao, X. H.²  Peng, Z. Z.²  You, J. H.³  Qiu, K. Q.³  Ma, X. L.² 

[1] Univ Sci & Technol China, Sch Mat Sci & Engn, Hefei 230026, Peoples R China

[2] Chinese Acad Sci, Shenyang Natl Lab Mat Sci, Inst Met Res, 72 Wenhua Rd, Shenyang 110016, Peoples R China

[3] Shenyang Univ Technol, Sch Mat Sci & Engn, 111 Shenliao West Rd, Shenyang 110178, Peoples R China

关键词: Magnesium alloys;    Long period stacking ordered (LPSO) structure;    HAADF-STEM;    Building block;   

DOI  :  10.1016/j.jallcom.2016.09.279

来源: Elsevier

【 摘 要 】

By atomic-scale high-angle annular dark field scanning transmission electron microscopy, we characterized a long period stacking ordered (LPSO) phase, 654R, in an Mg88Co5Y7 (at.%) as-cast alloy, which is an ordered intergrowth of 15R and 12H LPSO phases. The unique stacking sequence of 654R LPSO phase can be described as [(T2)(10)(T3 (T) over bar3)(14)](3), with lattice parameters of a = 0.321 nm, c = 170.4 nm, and a space group of R (3) over barm. T/(T) over bar refers to AB'C/AC'B building blocks, while normal and subscript number respectively represent the number of Mg layers sandwiched between T/(T) over bar and the number of sub unit cells. The formation mechanism of 654R LPSO phase is also proposed. (C) 2016 Elsevier B.V. All rights reserved.

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