2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 7: Yang Intl. Symp. / Multiscale Material Mechanics
| Editors: | Kongoli F, Aifantis E, Wang H, Zhu T |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 190 pages |
| ISBN: | 978-1-987820-48-5 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Atomistic modeling of history-independent cyclic fatigue of nanotwinned metals governed by correlated necklace dislocations
Haofei Zhou1; Huajian Gao2;1BROWN UNIV, Providence, United States; 2BROWN UNIVERSITY, Providence, United States;
Type of Paper: Regular
Id Paper: 250
Topic: 1
Abstract:
Nearly 90% of service failures of metallic components and structures are caused by fatigue at a cyclic stress amplitude much lower than the tensile strength of the materials involved. A long-standing obstacle to developing better materials with higher fatigue limit and longer fatigue life has been that metals typically suffer from large, accumulative, irreversible damages in microstructure during fatigue, leading to history-dependent and unstable cyclic responses. Here, we report atomistic modeling and simulations of a history-independent and stable cyclic response in nanotwinned metals and validate the results with experimental observations from our collaborating groups. We demonstrate that this unusual behavior is governed by a type of highly correlated necklace dislocations formed in the nanotwinned metal under cyclic loading. Our findings reveal a new route to improve the fatigue life of engineering materials through tailor-designed microstructure.