Deformation microstructures and strength of face-centered cubic high/medium entropy alloys

Shuhei Yoshida*, Takuto Ikeuchi, Yu Bai, Akinobu Shibata, N. Hansen, Xiaoxu Huang, Nobuhiro Tsuji

*Corresponding author for this work

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Abstract

In this study we report the deformation microstructures and strength of medium entropy alloys (MEAs) and high entropy alloys (HEAs), which are defined as alloys composed of four or less, and five or more principal elements, respectively, with (near-) equi-atomic concentrations. The friction stress (fundamental resistance to dislocation motion in the crystal lattice) and Hall-Petch relationship of various MEAs (CoCrFeNi, CoCrNi, etc.), taken as subsystems of the equi-atomic CoCrFeMnNi HEA, were precisely measured at room temperature. Experimental values of the friction stresses were found to fit with a theoretical model proposed by Toda-Caraballo et al. very well, which indicates that the strength of the alloys is closely related to a heterogeneously distorted crystal lattice. At the same time, values of the average lattice distortion in the alloys were found to be comparable to those in some dilute alloys, contradicting the belief that “severe” lattice distortion is a reason for the higher strength than in dilute systems. Finally, a strengthening mechanism due to element-element interactions was proposed as an additional mechanism in FCC HEAs and MEAs.
Original languageEnglish
Article number012053
JournalI O P Conference Series: Materials Science and Engineering
Volume580
Issue number1
Number of pages6
ISSN1757-8981
DOIs
Publication statusPublished - 2019
Event40th Risø International Symposium on Material Science: Metal Microstructures in 2D, 3D, and 4D - Roskilde, Denmark
Duration: 2 Sep 20196 Sep 2019

Conference

Conference40th Risø International Symposium on Material Science: Metal Microstructures in 2D, 3D, and 4D
CountryDenmark
CityRoskilde
Period02/09/201906/09/2019

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