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Valiev. Microstructures 2023;3:2023004 Microstructures
DOI: 10.20517/microstructures.2022.25

Technical Note Open Access

Nanostructural design of superstrong metallic

materials by severe plastic deformation processing

Ruslan Z. Valiev 1,2
1
Ufa University of Science and Technology, Ufa 450008, Russia.
2
Saint Petersburg State University, St. Petersburg 199034, Russia.
Correspondence to: Prof. Ruslan Z. Valiev, Ufa University of Science and Technology, 12 K. Marx Str., Ufa 450008, Russia. E-
mail: ruslan.valiev@ugatu.su

How to cite this article: Valiev RZ. Nanostructural design of superstrong metallic materials by severe plastic deformation
processing. Microstructures 2023;3:2023004. https://dx.doi.org/10.20517/microstructures.2022.25

Received: 7 Sep 2022 First Decision: 23 Sep 2022 Revised: 10 Oct 2022 Accepted: 2 Nov 2022 Published: 10 Jan 2023

Academic Editors: Daolun Chen, Yandong Wang Copy Editor: Fangling Lan Production Editor: Fangling Lan

Abstract
Ultrafine-grained (UFG) metallic materials processed by severe plastic deformation (SPD) techniques often exhibit
significantly higher strengths than those calculated by the well-known Hall-Petch equation. These higher strengths
result from the fact that SPD processing not only forms the UFG structure but also leads to the formation of other
nanostructural features, including dislocation substructures, nanotwins and nanosized second-phase
precipitations, which further contribute to the hardening. Moreover, the analysis of strengthening mechanisms in
recent studies demonstrates an important contribution to the hardening due to phenomena related to the structure
of grain boundaries as a non-equilibrium state and the presence of grain boundary segregations. Herein, the
principles of the nanostructural design of metallic materials for superior strength using SPD processing are
discussed.

Keywords: Nanostructural design, severe plastic deformation, ultrafine-grained materials, superior strength

INTRODUCTION
Although several factors determine the strength properties of pure metals and alloys, the average grain size
usually plays a significant role in their mechanical properties . In particular, the dependence of the
[1,2]
strength of polycrystalline materials on the average grain size d is usually described by the Hall-Petch
equation, according to which the yield stress σ is depicted as follows:
YS

© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0
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