Configuration of dislocations in low-angle kink boundaries formed in a single crystalline long-period stacking ordered Mg-Zn-Y alloy. (1st June 2018)

• Record Type: Journal Article
• Authors: Matsumoto, Tsubasa; Yamasaki, Michiaki; Hagihara, Koji; Kawamura, Yoshihito
• Is Part Of: Acta materialia. Volume 151(2018)
• Page Start: 112
• Page End: 124
• Publication Date: 2018-06-01
• Subjects: Magnesium -- Long-period stacking ordered structure -- Kink deformation -- Dislocation; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2018.03.034
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: The dislocation configuration around low-angle kink boundaries formed in bent single crystalline long-period stacking ordered (LPSO) Mg85 Zn6 Y9 alloys was investigated. Intragranular misorientation axis (IGMA) analysis through SEM/EBSD observation and gb analysis through TEM observation were conducted. Various kink bands possessing different lattice rotation axes ranging from < 1 1 ¯ 00 > to < 1 2 ¯ 10 >, i.e. along < 1 1 ¯ 00 >, < uvt 0>, and < 1 2 ¯ 10 > were revealed using IGMA analysis. TEM observation with gb analysis unveiled that the < 1 1 ¯ 00 >-rotation kink boundary observed using IGMA analysis consisted of basal < a > edge dislocations with one Burgers vector, while the < 1 2 ¯ 10 >/< uvt 0>-rotation kink boundaries were comprised of basal < a > edge dislocations with more than one Burgers vector. Low-angle kink boundaries were regarded as low-angle tilt boundaries consisting of perfect basal < a > dislocations, regardless of their rotation axes. The formation of various kink bands with < uvt 0>-combination-rotation axes ranging from < 1 1 ¯ 00 > to < 1 2 ¯ 10 > suggests that the statistically stored basal < a > dislocations may turn into geometrically necessary basal < a > edge dislocations during the initial stage of low-angle kink boundary formation. When a kink boundary is considered as a disclination, IGMA analysis capable of determining the lattice rotation axis and the angle is effective in evaluating the Frank vector of the kink boundary. Graphical abstract: Image 1