Non-Schmid behavior of extended dislocations in computer simulations of magnesium

0496954 - ÚFM 2019 RIV NL eng J - Journal Article
Ostapovets, Andriy - Vatazhuk, O.
Non-Schmid behavior of extended dislocations in computer simulations of magnesium.
Computational Materials Science. Roč. 142, FEB (2018), s. 261-267. ISSN 0927-0256. E-ISSN 1879-0801
R&D Projects: GA ČR(CZ) GA16-14599S; GA MŠMT(CZ) LQ1601
Institutional support: RVO:68081723
Keywords : resolved shear-stress * alloy az31b sheet * screw dislocations * bcc metals * peierls stress * single-crystals * glide * slip * law * basal * Dislocations * Magnesium * Crystal plasticity * Schmid law * Atomistic modeling
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 2.644, year: 2018

Critical resolved shear stresses are studied by means of atomistic simulations for dissociated screw dislocation with Burgers vector 1/3[11 (2) over bar0] in magnesium. Deviation from Schmid law is demonstrated for dislocation glide on basal and prismatic planes. It was shown that all stress components have influence on the critical resolved shear stress. The non-Schmid behavior is caused by changes of dislocation core width due to acting of non-glide stress components. In atomistic simulations, the critical resolved shear stress varies in the range of 0.2-6.7 MPa for basal slip and 25-55 MPa for prismatic slip depending on values of non-glide stress components. It is expected that such behavior can be partially responsible for scattering of experimental data for yield stress in magnesium. (C) 2017 Elsevier B.V. All rights reserved.
Permanent Link: http://hdl.handle.net/11104/0289567