Abstract Scope |
Recent studies of gradient nanotwinned copper, 3D-printed multi-component alloys, metallic nanocomposites, and several other heterogeneous materials raise a fundamental question on the role of microstructural heterogeneities, both topographic and chemical, in controlling the mechanical behavior of these novel material systems. Here we combine the mechanics modeling and experimental characterization to unravel the extra-strengthening effects of microstructural gradients and resultant plastic strain gradients and back stresses, as opposed to their homogeneous counterparts. Quantitative comparison is made between modeling and experimental results, highlighting the less appreciated notions of different types of back-stress hardening or different stages of extra-hardening that can operate in the same material system with complex microstructural heterogeneities. New insights are obtained for promoting the strength-ductility synergy in the design of high-performance heterogeneous materials. |