Ab initio tensile tests of grain boundaries in the fcc crystals of Ni and Co with segregated sp-impurities

0464551 - ÚFM 2017 RIV CH eng J - Článek v odborném periodiku
Černý, Miroslav - Šešták, Petr - Řehák, Petr - Všianská, Monika - Šob, Mojmír
Ab initio tensile tests of grain boundaries in the fcc crystals of Ni and Co with segregated sp-impurities.
Materials Science and Engineering A Structural Materials Properties Microstructure and Processing. Roč. 669, JUL (2016), s. 218-225. ISSN 0921-5093. E-ISSN 1873-4936
Grant CEP: GA ČR(CZ) GA16-24711S; GA ČR(CZ) GAP108/12/0311; GA MŠMT(CZ) LQ1601
Institucionální podpora: RVO:68081723
Klíčová slova: Theoretical strength * Computational tensile test * Grain boundary embrittlement * Ab initio calculations
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 3.094, rok: 2016

Models of Sigma 5(210) grain boundaries in crystals of fcc Ni and fcc Co with segregated sp-impurities (Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb, and Te) have been subjected to ab initio computational tensile tests. Two models of deformation (rigid grain shift and uniaxial loading) have been considered and their results have been compared. The results reveal striking differences in predictions from the models. Poisson contraction included in the model of uniaxial loading remarkably reduces the computed strength values but, unlike the rigid grain shift, predicts an enhancement of the grain boundary strength due to the presence of impurities (particularly those segregated in interstitial positions). These different predictions are discussed in terms of the effect of transverse stresses on the computed strength values.
Trvalý link: http://hdl.handle.net/11104/0263560