ICAMS / Interdisciplinary Centre for Advanced Materials Simulation

Mechanical Properties of Interfaces

Rebecca Janisch

The research group “Mechanical Properties of Interfaces” carries out atomistic simulations to understand the fundamental processes that occur at interfaces under different loading conditions, and which determine the strength and deformability of polycrystalline microstructures in metals and alloys. Based on this understanding predictive physical models are established that connect the atomistic details of individual grain boundaries, such as structural units and chemical composition, to the effective interface behaviour. Such models can be used in mesoscale simulations of microstructure evolution, deformation, and fracture to identify microstructures with optimised mechanical properties.

Recent work focused on the effect of alloying elements, vacancies, and strain on the deformability and strength of ferritic steel, as well as on the effect of strain and interface structure on the deformation mechanisms in aluminium and titanium-aluminium alloys. In both cases fundamental physical and structural properties could be connected to the mesoscopic behaviour either observed experimentally or in molecular dynamics simulations. For instance the dynamical shear behavior of grain boundaries in face-centred cubic Al as well as in γ-TiAl revealed several deformation mechanisms that can be understood based on a multi-layer analysis of the stacking fault energies in the grain boundary and adjacent planes. This allows the formulation of an energy-based model of shear that can in turn be used for ab-initio based alloy design.

Competences

  • Structure and properties of interfaces in materials
  • Ab initio density functional theory
  • Scale bridging approaches

Group Members

 

The Janisch group in April 2018 (from left to right): Lobna Saeed Abdel Razik Aly, Ashish Chauniyal, Abril Azócar Guzmán, Egbe Stewart, Rebecca Janisch, Kevin Janowiak, Smobin Vincent. Daniel Finger is missing.


Contact

Dr. habil. Rebecca Janisch
ICAMS
Ruhr-Universität Bochum
44780 Bochum
Germany

Tel. +49 234 32 29304
Fax +49 234 32 14984
rebecca.janisch@rub.de

Recent publications

J. Möller, E. Bitzek, R. Janisch, H. ul Hassan et al. Fracture ab initio: A force-based scaling law for atomistically informed continuum models Journal of Materials Research, 33, 3750 - 3761, (2018)

M. Kanani, A. Hartmaier, R. Janisch. The shear instability energy: a new parameter for materials design? Modelling and Simulation in Materials Science and Engineering, IOP Publishing Ltd, Bristol and Philadelphia, 25, 075009, (2017)

H. Dette, J. Gösmann, C. Greiff, R. Janisch. Efficient sampling in materials simulation - Exploring the parameter space of grain boundaries Acta Materialia, 125, 145-155, (2017)

J. Wang, R. Janisch, G. Madsen, R. Drautz. First-principles study of carbon segregation in bcc iron symmetrical tilt grain boundaries Acta Materialia, 115, 259-268, (2016)

M. Kanani, A. Hartmaier, R. Janisch. Stacking fault based analysis of shear mechanisms at interfaces in lamellar TiAl alloys Acta Materialia, 106, 208-218, (2016)