Journal ArticleDOI
Universal binding energy relation for cleaved and structurally relaxed surfaces.
Aarti Srirangarajan,Aditi Datta,Appala Naidu Gandi,Upadrasta Ramamurty,Upadrasta Ramamurty,Umesh V. Waghmare +5 more
TLDR
It is found that the cohesive law (stress-displacement relation) differs significantly in the case where cracked surfaces are allowed to relax, with lower peak stresses occurring at higher displacements.Abstract:
The universal binding energy relation (UBER), derived earlier to describe the cohesion between two rigid atomic planes, does not accurately capture the cohesive properties when the cleaved surfaces are allowed to relax. We suggest a modified functional form of UBER that is analytical and at the same time accurately models the properties of surfaces relaxed during cleavage. We demonstrate the generality as well as the validity of this modified UBER through first-principles density functional theory calculations of cleavage in a number of crystal systems. Our results show that the total energies of all the relaxed surfaces lie on a single (universal) energy surface, that is given by the proposed functional form which contains an additional length-scale associated with structural relaxation. This functional form could be used in modelling the cohesive zones in crack growth simulation studies. We find that the cohesive law (stress-displacement relation) differs significantly in the case where cracked surfaces are allowed to relax, with lower peak stresses occurring at higher displacements.read more
Citations
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Density functional theory in the canonical ensemble I General formalism
TL;DR: In this paper, the Hohenberg-Kohn-Sham-Mermin (HKSM) theorem in the grand canonical ensemble (GCE) was extended to the CE and the correlation functions were stripped off of their asymptotic behaviour.
Journal ArticleDOI
On the role of hydrogen filled vacancies on the embrittlement of zirconium: An ab initio investigation
TL;DR: In this paper, an ab initio study of the influence of hydrogen filled vacancies on the mechanical properties of zirconium was carried out and the results of the modelling imply that the work of fracture and peak stress decrease as a result of the presence of hydrogen-filled vacancies.
Journal ArticleDOI
First principles characterisation of brittle transgranular fracture of titanium hydrides
TL;DR: In this article, the authors have studied transgranular cleavage and fracture toughness of titanium hydrides by means of quantum mechanical calculations based on density functional theory, and they have shown that the fracture strength of the hydride can be improved by using a density functional model.
Journal ArticleDOI
High-throughput screening of the static friction and ideal cleavage strength of solid interfaces.
TL;DR: The ratio between the frictional and cleavage strengths is provided as good indicator for the material failure mode – dislocation propagation versus crack nucleation.
Journal ArticleDOI
Fracture of coherent interfaces between an fcc metal matrix and the Cr 23 C 6 carbide precipitate from first principles
TL;DR: In this paper, the key properties of carbide-metal interfaces controlling the energy and critical stress of fracture, based on density functional theory (DFT) calculations, are determined, and the critical stresses of both intraprecipitate and interfacial fractures due to a tensile loading are estimated via the universal binding energy relation (UBER) model, parametrized on the DFT data.
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