In situ transmission electron microscopy investigation on 〈c + a〉 slip in Mg. Issue 9 (11th February 2019)

• Record Type: Journal Article
• Authors: Zhang, Dalong; Jiang, Lin; Wang, Xin; Beyerlein, Irene J.; Minor, Andrew M.; Schoenung, Julie M.; Mahajan, Subhash; Lavernia, Enrique J.
• Is Part Of: Journal of materials research. Volume 34:Issue 9(2019)
• Page Start: 1499
• Page End: 1508
• Publication Date: 2019-02-11
• Subjects: Mg, -- dislocations, -- transmission electron microscopy; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1557/jmr.2018.487
• Languages: English
• ISSNs: 0884-2914

Abstract

Abstract: Abstract : Recent molecular dynamics simulations revealed that 〈 c + a 〉 dislocations in Mg were prone to dissociation on the basal plane, thus becoming sessile. Basal dissociation of 〈 c + a 〉 dislocations is significant because it is a major factor in the limited ductility and high work-hardening in Mg. We report an in situ transmission electron microscopy study of the deformation process using an H-bar-shaped thin foil of Mg single crystal designed to facilitate 〈 c + a 〉 slip, observe 〈 c + a 〉 dislocation activity, and establish the validity of the largely immobile 〈 c + a 〉 dislocations caused by the predicted basal dissociation. In addition, through detailed observations on the fine movement of some 〈 c + a 〉 dislocations, it was revealed that limited bowing out movement for some non-basal portions of 〈 c + a 〉 dislocations was possible; under certain circumstances, i.e., through attraction and reaction between two 〈 c + a 〉 dislocations on the same pyramidal plane, at least portions of the sessile configuration were observed to be reversed into a glissile one.