| Kink Microstructures and Solute Segregations in LPSO/MFS-Structured Mg Alloys Daisuke Egusa1; Eiji Abe1; 1THE UNIVERSITY OF TOKYO, Bunkyo-ku, Japan; PAPER: 291/Magnesium/Regular (Oral) SCHEDULED: 14:50/Thu. 24 Oct. 2019/Adonis ABSTRACT: Magnesium (Mg) alloys containing long-period stacking/ordered (LPSO) phases have been gathering increasing attention owing to their superior strength and unique deformation mode: "kink" [1]. Kink is a type of plastic deformation that introduces rotation of crystal which has been reported as a deformation mode that is activated in highly anisotropic materials [2]. Since high strength of the LPSO type Mg alloys are realized after high temperature processing, i.e., introducing kink deformed microstructure, kink deformation is believed to play an important role in mechanical properties [3]. In the present study, we investigated microstructures of kinks while especially focusing on solute segregations around boundaries which are known to significantly affect mechanical properties of Mg alloys [4]. Atomic structure and solute segregations at the kink boundaries were directly observed by scanning transmission electron microscopy (STEM). STEM observations clearly show that kink boundaries consist of arrays of basal dislocations extended into Shockley-type partial dislocations. In addition, solute elements segregated within stacking faults were introduced by the extended basal dislocations. The solute segregations around kink boundaries, which can be understood as Suzuki effect, would improve thermodynamic stability of kink microstructure. References: [1] Y. Kawamura et al., Mater Trans. 48 (2007) 2986-2992.<br />[2] E. Orowan, Nature, 149 (1942) 643-644. <br />[3] K. Hagihara et al., Intermetallics, 18 (2010) 1079-1085.<br />[4] M. Bugnet et al., Acta Mater., 79 (2014) 66-73. |
