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Modelling of Size Effects in Mechanical Properties: the Influence of Oxygen

English title Modelling of Size Effects in Mechanical Properties: the Influence of Oxygen
Applicant Van Swygenhoven Helena
Number 109289
Funding scheme Project funding
Research institution Paul Scherrer Institut
Institution of higher education Paul Scherrer Institute - PSI
Main discipline Material Sciences
Start/End 01.05.2006 - 30.04.2010
Approved amount 132'747.00
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Keywords (4)

molecular dynamics; mechanical properties; nanostructured metals; size effects

Lay Summary (English)

Lay summary
The main scientific objective of this proposal is to study by means of molecular dynamics how the presence of oxygen/oxides on surfaces/interfaces affects plasticity in nanocrystalline metals and in micron sized metallic objects, contributing to the challenging research in size effects of mechanical properties. These simulations have the aim to reduce one of the striking differences between molecular dynamics simulations and experiments in micro-nanomechanics: i.e. the role of oxides in surfaces/interfaces.
In particular, simulations will involve atomic configurations of two distinctive geometries under load: (1) a bulk nanocrystalline system with oxygen dispersed throughout the material (with oxygen concentrations up to 10 atom-percent) and (2) a free-standing single crystal system with a metal-oxide layer grown on the surface. The basic questions that will be addressed are (1) how oxygen affects dislocation nucleation from grain boundaries and (2) how an oxide surface layer affects slip initiation in micron-limited single crystal objects.
This objective needs the development of an improved working tool:, an autonomous procedure to recognise the appropriate length and time scale for the treatment of the variable charge problem will be implemented on top of an existing parallel code, reducing the computational load associated with the recognised bottlenecks of the technique.
The technical development associated with the optimization will be in collaboration with Drs. O. Politano and A. Hasnaoui of the University of Bourgogne, Dijon, France, who already have extensive experience with the parallel “variable charge” code.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants


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Associated projects

Number Title Start Funding scheme
100055 Atomistic simulation of bimodal and textured grain size distributions in nanocrystalline metals: structure and mechanical properties 01.07.2003 Project funding