|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Mechanical Behavior of Nanostructured Materials
||Back-stress Strengthening and Strain Hardening in Heterogeneous Materials
||Muxin Yang, Fuping Yuan, Xiaolei Wu, Yuntian Zhu
|On-Site Speaker (Planned)
Heterogeneous materials have a superior combination of strength and ductility that is not accessible to their homogeneous counterparts. A previously not-well-understood mechanism, back-stress strengthening and back-stress strain hardening, is found responsible for such a dramatic improvement of mechanical properties in heterogeneous materials. Back stress is long-range stress caused by the pileup of geometrically necessary dislocations. We have developed a simple equation and procedure to calculate the back stress basing on its formation physics from the tensile unloading-reloading hysteresis loop. Heterogeneous structures have a mechanical incompatibility due to the grain size difference in different structural domains. This induces strain gradient, which needs to be accommodated by geometrically necessary dislocations. Back stress not only raises the yield strength but also significantly enhance strain hardening to increase the ductility. Utilizing back-stress hardening to design metals and alloys for superior mechanical properties represents a new design paradigm that may produce disruptive mechanical properties.
||Planned: Supplemental Proceedings volume