|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Ultrafine-grained and Heterostructured Materials (UFGH XII)
||Origin of Extra Strengthening in Gradient Nanotwinned Metals
||Yin Zhang, Zhao Cheng, Linfeng Bu, Hengan Wu, Lei Lu, Ting Zhu
|On-Site Speaker (Planned)
Materials containing heterogeneous nanostructures hold great promise for achieving superior mechanical properties. However, the strengthening effect due to plastically inhomogeneous deformation in heterogeneous nanostructures has not been clearly understood. Here we investigate a prototypical nanostructured material of gradient nanotwinned (GNT) Cu to unravel the mechanistic origin of extra strengthening associated with gradient twin structures. We characterize the mechanical heterogeneity in gradient nanotwins in terms of back and effective stresses, as compared with those from homogeneous nanotwinned components. The results reveal a new type of back stress that predominantly controls the extra strengthening of GNT Cu. Such extra back stress results from the plastic strain gradient and associated bundles of concentrated dislocations that stem from the structural gradient in GNT Cu. This work establishes mechanistic linkages between the extra strength and gradient structure in GNT Cu and thus exemplifies a general approach to unraveling the strengthening mechanism of heterogeneous nanostructured materials.
||Copper / Nickel / Cobalt, Modeling and Simulation,