Impact of non-Schmid stress components present in the yield criterion for bcc metals on the activity of {110}<111> slip systems

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F19%3A00498668" target="_blank" >RIV/68081723:_____/19:00498668 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0927025618308000?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0927025618308000?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.commatsci.2018.12.021" target="_blank" >10.1016/j.commatsci.2018.12.021</a>

Result language

angličtina

Original language name

Impact of non-Schmid stress components present in the yield criterion for bcc metals on the activity of {110}<111> slip systems

Original language description

It has been found in a number of computer simulations that the yield criterion for the onset of crystal plasticity ofnbody-centered cubic (bcc) metals generally involves stress components other than the shear stress parallel to thenslip direction. This is a consequence of the non-planar cores of 1/2<111> screw dislocations that control the plastic deformation of bcc crystals. The significance of these non-Schmid stress components differs from material to material and thus their contributions to the yield criterion requires either extensive atomistic simulations ofnisolated 1/2[111] screw dislocations or their estimates from experiments. In this paper, we derive a set of con-nstraints imposed on the parameters of the yield criterion that control the importance of different stress com-nponents so that the orientation dependence of the critical resolved shear stress and its dependence on the shearnstress perpendicular to the slip direction have trends agreeing with atomistic computer simulations. Using thenallowed combinations of these parameters, we identify the primary and secondary {110}<111> slip systems fornloadings in tension and compression along three specifically oriented loading axes within the standard stereo-ngraphic triangle. In this context we show that the origin of the tension-compression asymmetry is not relatednpurely to the well-known twinning-antitwinning asymmetry of the yield stress but to a combination of thisnasymmetry with the effect of the shear stresses perpendicular to the slip direction. Additionally, we demonstratenthat our yield criterion, which is based only on the shear stresses parallel and perpendicular to the slip direction,nis fully equivalent to more complex yield criteria that contain explicit dependences on normal stresses per-npendicular and parallel to the dislocation line. These additional stress terms are shown to emerge due to pro-njection of the applied stress tensor into an orthogonal basis that does not conform with the three-fold screwnsymmetry of the <111> rotation axis implicit in bcc crystal structures.n

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Computational Materials Science

ISSN

0927-0256

e-ISSN

—

Volume of the periodical

159

Issue of the periodical within the volume

MAR

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

9

Pages from-to

297-305

UT code for WoS article

000457856900029

EID of the result in the Scopus database

2-s2.0-85058694788