Multi-scale Computational Design of Solute Strengthened Aluminum Alloys
William Curtin (EPFL), Shyam Keravalarma (EPFL), Allan Bower (Brown University), Louis J. Hector, Jr. (General Motors R&D), Raj Mishra (GM Research and Development Center, Warren, Michigan, 48090)
Computational Materials Design via Multi-scale Modeling
Wed 10:45 - 12:15
Barus-Holley 190
Al and Mg alloys have the potential to significantly reduce vehicle weight. Their widespread use is limited partly by poor room temperature formability. The ductility of both Al and Mg alloys is strongly sensitive to their composition, which offers the potential to develop new alloys with enhanced formability. Predicting the influence of alloy chemistry on flow strength and ductility is thus of considerable interest. To this end, we will describe a hierarchical multi-scale computational method that predicts the influence of composition on the flow strength and tensile ductility of solute strengthened Al alloys. The computations begin with ab-initio computations of solute/dislocation interaction energies in the alloys of interest; proceed through kinetic montecarlo and MD simulations of dislocation motion through solute clouds, and end with atomistically-calibrated constitutive laws that are suitable for FEA simulations of forming of 3D parts. The model predictions are compared with experimental measurements of flow strength and tensile ductility of representative Al alloys as functions of alloy composition, strain rate and temperature. Using this multiscale framework, we propose an optimization scheme for design of new alloy compositions to maximize the ductility at fixed yield strength