Tension–compression creep asymmetry in strong-textural Mg-RE alloy due to <c + a> dislocation reconfiguration
Dongdong Zhang, Sheng Wang, Chaojie Che, Zhanyong Zhao, Ke Li, Zhangbo Ma, Peikang Bai
Abstract
Strong-textural Mg-RE alloy exhibits creep asymmetry at 200°C, with a much higher creep resistance in compression than in tension, albeit a higher yield strength in tension than in compression. Creep asymmetry is ascribed to the non-Schmid effects of pyramidal <c + a> slip, which enables a higher friction in compression and thus induces a lower mobility of pyramidal <c + a> slip in compression than in tension. Additionally, the dissociation of <c + a> dislocations into sessile structures in compression is more frequent than in tension, which contributes to the hardening response and thus lowers the compressive creep rate.
Topics & Concepts
Materials scienceDislocationAlloyCreepAsymmetryCompression (physics)Tension (geology)MetallurgyComposite materialCrystallographyQuantum mechanicsChemistryPhysicsMagnesium Alloys: Properties and ApplicationsAluminum Alloys Composites PropertiesMicrostructure and mechanical properties