| Linking intrinsic properties with deformation mechanisms of interface-dominated nanostructured materials |
| Paper ID : 1389-UFGNSM-FULL |
| Authors: |
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Mansour Kanani *1, Alexander Hartmaier2, Rebecca Janisch2 1Shiraz University, Shiraz 2Interdisciplinary Centre for Advanced Materials Simulation (ICAMS); Ruhr-Universität Bochum, Germany |
| Abstract: |
| Predictive and reliable relationships between fundamental microstructural material properties and observable macroscopic mechanical behavior are crucial for understanding of nanostructured materials. In many interface-dominated nanostructured materials the role of interfaces during deformation is not yet completely clarified. Very fine spacing of interfaces leads to a competition between dislocation controlled and grain boundary sliding based plasticity. To improve our understanding of this competition we have to investigate the atomistic origin of ductility in the interface region. A multi-scale concept is introduced to capture effects of both the electronic and the atomistic level at interfaces in nano-lamellar TiAl alloys. We use recently introduced materials parameter, the shear instability energy $Gamma$, to link between physical properties that are defined on the atomic level and the deformation mechanisms of slip planes and interfaces that govern the mechanical behavior of a material. in this study at TiAl nanolaminated nanostructures atomistic origin of different deformation mechanismsof two microscopically similar interfaces , i.e. the pseudo-twin (PT) and rotational boundary (RB) interfaces, using a G-based algorithm is investigated. First, the G was obtained along various crystal directions via quasi-static calculations of multi-planar generalized stacking fault energy (MGSFE) surfaces of the interface plane as well as the adjacent layers. Second, molecular dynamics simulations guided by ab initio GSFE calculations were carried out for different bicrystal cells under different shear loading conditions. The results show a clear intrinsic difference of atomic planes arrangement of two interfaces via MGSFE analysis for specific directions which are typically hidden for experimental studies. Furthermore, the capability of the calculated G parameter for predicting such a different deformation behavior in spite of microscopic similarities is illustrated. |
| Keywords: |
| multi-scale simulation, interface-dominated nanostructure, Shear instability energy |
| Status : Paper Accepted (Oral Presentation) |
