ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


The shear instability energy as a new parameter to characterise deformation behaviour of materials

Date: 22.03.2017
Time: 11:30 a.m.
Place: DPG Spring Meeting, Dresden, Germany

Rebecca Janisch
Mansour Kanani
Alexander Hartmaier

Systematic relationships between a limited number of fundamental material properties and the observable behaviour of a material are needed for successful design of new materials. To this purpose we introduce the shear instability energy Γ as a new materials parameter. Using interfaces in lamellar TiAl as a case study, we show that Γ can link stacking fault energies from a quasistatic (e.g. ab initio density functional theory based) calculation with the deformation mechanisms that are observed in a molecular dynamics simulation of shear.
Furthermore the shear instability energy can be used to scale between the results of calculations with different interatomic potentials,i.e. also to evaluate trends in deformation mechanisms across differentelements. In this the concept of the shear instability energy is more comprehensive than models which rely only on the ratio of unstable and stable stacking fault energies. This makes it a promising tool for enhancing high-throughput characterization of materials.

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