TWINNING AND DETWINNING MECHANISMS IN NANOTWINNED MATERIALS

1,2,3 Skiba Nikolay
Co-authors:
3 BoByL Ekaterina 3 MIHEEV Dmitriy
Institutions:
1 Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia
2 Department of Mathematics and Mechanics, St. Petersburg State University, St. Petersburg, Russia
3 Research Laboratory for Mechanics of New Nanomaterials,Peter the Great St. Petersburg Polytechnical University, St. Petersburg, Russia
Conference:
9th International Conference on Nanomaterials - Research & Application, Hotel Voronez I, Brno, Czech Republic, EU, October 18th - 20th 2017
Proceedings:
Proceedings 9th International Conference on Nanomaterials - Research & Application
Pages:
930-936
ISBN:
978-80-87294-81-9
ISSN:
2694-930X
Published:
8th March 2018
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
32 views / 12 downloads
Abstract

The theoretical models are suggested which describe specific plastic deformation mechanisms in nanotwinned materials. Materials containing high-density ensembles of nanoscale twins (nanotwinned materials) exhibit the outstanding mechanical and physical properties - simultaneously high strength and functional ductility at room temperature. These characteristics are achieved due to operating of the specific deformation modes in nanotwinned materials. The theoretical models are suggested which describe specific plastic deformation mechanisms in nanotwinned materials. In the framework of the suggested models, micromechanism of nanotwin widening and micromechanism of combined action of lattice dislocation slip and twin boundary migration in nanotwinned materials are considered. In addition, the detwinning mechanism in ultrafine-grained nanotwinned metals through stress-driven migration of incoherent boundaries of nanoscale twins is examined. It is demonstrated that detwinning of ultrathin twins can occur at very low stresses, while detwinning of thicker twins requires high applied stresses. The theoretical results and their comparison with corresponding experimental data in the exemplary case of nanotwinned cooper (Cu) are discussed.

Keywords: nanotwinned materials, nanotwins, plastic deformation, twinning, detwinning.
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