|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Multiscale Architectured Materials (MAM II): Tailoring Mechanical Incompatibility for Superior Properties
||Strain Incompatibility and Ductility in a Gradient Nanostructure of IF Steel
||Xiaolei Wu, Yuntian Zhu
|On-Site Speaker (Planned)
The origin behind large uniform tensile ductility in the gradient nanostructure (GNS) is still an open issue. Recently, it was reported that the GNS exhibits the Bauschinger effect during the tensile unloading-reloading cycle, indicative of strain incompatibility due to the microstructural heterogeneity in the GNS. Here we report the effect of back stress hardening on the tensile property in the gradient structure. It is observed that the gradient structures increase the yield strength and maintain the large uniform elongation comparable to that of the coarse-grained counterpart. The strain hardening due to back stresses is both depth and tensile strain dependence, which makes up for deficiencies of forest hardening. Even with the presence of the yield-peak, the hardening rate up-turns in the transient to obtain large uniform elongation. Gradient structures exhibit an anti-banana-type yield strength versus ductility synergy.