Due to the gradual size reduction of engineering products, micro-and nanomechanical testing procedures are becoming more important. Many modern devices approach grain scale dimensions, e.g. MEMS, stents, microcantilevers and compounds in electronic packaging. Therefore, better understanding of crystal-scale elasto-plastic deformation mechanisms at these dimensions is required.
Due to the difficulty in monitoring the exact boundary conditions of mechanical tests at small scales, it is helpful to conduct corresponding crystal plasticity finite element (CPFE) simulations. [1] Such models may help to discover possible inaccuracies in the experimental boundary conditions and their possible influence on the microstructure and texture evolution. [2] Crystal mechanical simulations, therefore, provide a reference to design well-defined small-scale tests. In addition, they allow one to predict internal material parameters (e.g. dislocation density) that cannot be directly monitored during the mechanical experiments. CPFE simulations hence provide a virtual laboratory to conduct numerical experiments with systematically modified process parameters and boundary conditions to design and accompany corresponding mechanical small-scale experiments. [3] In this study, we investigate bending of a single crystal copper nanowire. [4] In this context, mechanical size effects deserve particular attention. [4][5][6] The constitutive model used for the CPFE simulation considers these effects in terms of a dislocation based hardening model including geometrically necessary dislocations (GND). [7][8][9][10] Bending was performed because it leads to high deformation gradients.