Molecular dynamics simulations on the influence of precipitates on the strain localization in aged Al-Mg alloys

• Applicant: Professor Dr. Siegfried Schmauder
• Subject Area: Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 269506753

The strain localization in metallic materials is, at the atomic level, governed by the propagation of dislocations, the movement of foreign atoms in the vicinity of dislocations, the interaction of dislocations with each other and by the interaction of dislocations with inhomogeneities (solid soluted atoms, precipitates and grain boundaries). At the macroscopic level, the effect of precipitates on the mechanical properties of Al-Mg alloys can be noticed in the form of an uneven deformation behavior during tensile tests. This is also known as the Portevin - Le Chatelier (PLC) effect.Despite extensive experimental results to the PLC effect and advanced simulation methods, the basic phenomena of the PLC effect at the atomistic scale are still not fully understood. It is our intention to systematically close this gap within the frame of the proposed project. Processes contributing to the material hardening in Al-Mg alloys will be investigated at the nanoscale level with the help of molecular dynamics (MD) simulations.Critical resolved shear stresses (CRSS), originating from various precipitate types and sizes and calculated by MD in order to investigate their influence onto the material hardening. Both stress- and strain controlled deformations will be simulated, the results will be validated by each other as well as by literature values.

• DFG Programme: Research Grants