Texture mediated grain boundary network design in three dimensions

Abstract

Experimental grain boundary engineering studies have demonstrated the potential for materials properties enhancement via the modification of grain boundary network structure. These techniques apply to materials that readily form annealing twins and are amenable to cyclic thermomechanical processing and have resulted in dramatic property enhancement. In this work we present a theoretical framework that enables the design of grain boundary networks in polycrystalline materials through an alternative approach: exploitation of a relationship between crystallographic texture and grain boundary network structure. Because crystallographic texture is a universal characteristic of polycrystalline materials, this work has the potential to significantly expand the class of materials whose grain boundary networks can be controlled. We demonstrate the utility of the approach by application to a concrete design problem involving competing design objectives for yield strength, elastic compliance, and resistance to electromigration. We construct the first materials properties closure to comprise grain boundary network sensitive properties and identify an optimal microstructure that is predicted to outperform an undesigned isotropic material.