University of Oulu

Sumit Ghosh, Madan Patnamsetty, Mahesh C. Somani, Pasi Peura, Characteristics of dynamic softening during high temperature deformation of CoCrFeMnNi high-entropy alloy and its correlation with the evolving microstructure and micro-texture, Journal of Materials Research and Technology, 2021, ISSN 2238-7854, https://doi.org/10.1016/j.jmrt.2021.11.089

Characteristics of dynamic softening during high temperature deformation of CoCrFeMnNi high-entropy alloy and its correlation with the evolving microstructure and micro-texture

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Author: Ghosh, Sumit1; Patnamsetty, Madan2; Somani, Mahesh C.1;
Organizations: 1Materials and Mechanical Engineering, Centre for Advanced Steels Research, University of Oulu, 90014, Finland
2Materials Science and Environmental Engineering, Tampere University, 33720, Tampere, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 15.9 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe2021120158196
Language: English
Published: Elsevier, 2021
Publish Date: 2021-12-01
Description:

Abstract

The characteristics of dynamic recrystallization (DRX) of a CoCrFeMnNi high–entropy alloy (HEA) was investigated via hot compression testing in the temperature range 950–1100 °C and at true strain rates of 10–2 and 10–1 s-1. The discontinuous DRX was found to be the dominant mechanism corroborating the microstructural evolution. The progress of the initiation of DRX was investigated in terms of critical strain/stress required using the Poliak–Jonas analytical criterion. Consequently, a new kinetic model based on Avrami–type function was established for the HEA to predict the DRX fractional recrystallization. It was revealed that the volume fraction of DRX grains increased with increasing strain. In the case of 10–2 s-1, steady–state flow was achieved after the completion of one DRX process cycle resulting in further straining, leading to the occurrence of dynamic restoration processes involving formation of substructures and generation and annihilation of dislocations inside the DRX grains which effectively increased the fraction of partially deformed DRX (substructured) grains. A good agreement between the proposed DRX kinetics model and microstructure observation results validated the accuracy of DRX kinetics model for CoCrFeMnNi HEA. The preferred orientation of the non–recrystallized grains was towards the formation of <101> fiber texture, whereas a random micro–texture is revealed in the recrystallized grains.

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Series: Journal of materials research and technology
ISSN: 2238-7854
ISSN-E: 2214-0697
ISSN-L: 2238-7854
Volume: In press
DOI: 10.1016/j.jmrt.2021.11.089
OADOI: https://oadoi.org/10.1016/j.jmrt.2021.11.089
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Subjects:
Copyright information: © The Author(s) 2021. Published by Elsevier. Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0).
  https://creativecommons.org/licenses/by-nc-nd/4.0/