About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
|
Deformation and Transitions at Grain Boundaries VII
|
Presentation Title |
Unusual Size Effects from Tilted Twin Boundaries in Nano-twinned Metals |
Author(s) |
Caizhi Zhou, Sixie Huang, Irene J. Beyerlein |
On-Site Speaker (Planned) |
Caizhi Zhou |
Abstract Scope |
Nano-twinned (NT) metals have demonstrated exciting potential to break the strength-ductility trade-off, providing high strength without the loss of ductility. Tilted twin boundaries (TBs) naturally occur in columnar-grained NT metals. Here, using a combination of atomistic simulations and theoretical model, we study the effect of tilted TBs on the twin layer size effect on strength. Our results reveal that NT metals with the ideal TB orientation (i.e., with no tilt) exhibit continuously increasing strength with decreasing twin thickness and no inverse size effect. In contrast, NT metals with tilted TBs exhibit an inverse size effect, and the critical twin thickness, below which strength decreases, increases as the TB-tilt angle increases. Furthermore, the investigation identifies a critical value of TB tilt for which strength becomes independent of twin thickness and is the weakest. Our results provide the insights for the guideline of design of NT metals with desired properties. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |