Effect of V Content on the Microstructure and Mechanical Properties of High-Pressure Torsion Nanostructured CoCrFeMnNiV_x High-Entropy Alloys

Author(s)

Elena D. Tabachnikova, Sergej N. Smirnov, Yuriy O. Shapovalov, Igor V. Kolodiy, Anastasia V. Levenets, Mikhail A. Tikhonovsky, Michael J. Zehetbauer, Christian Rentenberger, Erhard Schafler, Yi Huang, Terence G. Langdon

Abstract

The article presents investigations of microstructure and low-temperature mechanical properties of nanostructured alloys CoCrFeMnNiV_x (x = 0.15–0.75), processed by high-pressure torsion (HPT) at temperatures of 300 and 77 K. While at x ≥ 0.5 the values of microhardness (H_v) and compression yield stress (σ_0.2) in samples after HPT at 77 K are larger than those in samples after HPT at 300 K, for x ≤ 0.2 surprisingly the opposite effect is observed. As in case of the undeformed CoCrFeMnNiV_x alloys, the behavior for vanadium concentrations x ≥ 0.5 can be related to the formation of tetragonal σ-phase in addition to face-centered cubic matrix, while the anomalous behavior for x ≤ 0.2 arises from the formation of HPT-induced hexagonal martensitic phase. In the low-temperature ranges, i.e., 20–300 K in case of HPT nanostructured CoCrFeMnNiV_0.2, and 150–300 K in case of HPT nanostructured CoCrFeMnNiV_0.5, dependences of σ_0.2(T) show characteristics of thermally activated dislocation movement. For the first time in high-entropy alloys, anomalous dependences of σ_0.2(T) at temperatures 4.2–20 K for CoCrFeMnNiV_0.2, and at 80–150 K for CoCrFeMnNiV_0.5 are found, which indicate at the occurrence of nonthermal inertial dislocation movement.

Organisation(s)

Dynamics of Condensed Systems, Physics of Nanostructured Materials

External organisation(s)

National Academy of Sciences of Ukraine (NASU), National Science Center Kharkiv Institute of Physics and Technology (KIPT), Bournemouth University, University of Southampton

Journal

Advanced Engineering Materials

Volume

26

No. of pages

12

ISSN

1438-1656

DOI

https://doi.org/10.1002/adem.202400692

Publication date

10-2024

Peer reviewed

Yes

Austrian Fields of Science 2012

103018 Materials physics, 103042 Electron microscopy

Keywords

ASJC Scopus subject areas

General Materials Science, Condensed Matter Physics

Portal url

https://ucrisportal.univie.ac.at/en/publications/6090d8c8-d551-4d05-be77-1b6b5ca9a344