A critical evaluation of microstructure-texture-mechanical behavior heterogeneity in high pressure torsion processed CoCuFeMnNi high entropy alloy

Sonkusare, R and Biswas, K and Al-Hamdany, N and Brokmeier, HG and Kalsar, R and Schell, N and Gurao, NP (2020) A critical evaluation of microstructure-texture-mechanical behavior heterogeneity in high pressure torsion processed CoCuFeMnNi high entropy alloy. In: Materials Science and Engineering A, 782 .

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Abstract

The present study aims to understand the evolution of textural and microstructural heterogeneity and its effect on evolution of mechanical properties of an equiatomic FCC CoCuFeMnNi high entropy alloy (HEA) disc subjected to high pressure torsion (HPT). HPT was performed on disc specimen with a hydrostatic pressure of 5 GPa for 0.1, 0.5, 1 and 5 turns at room temperature where the hardness saturated at 1941 MPa at the periphery of the sample after five turns. Synchrotron diffraction texture analysis of five-turn HPT sample reveals characteristic shear texture with the dominance of A 11�1�<110> and A* 11�1�<112> components near central region of the disc and it shifts to C 001<110> component near the periphery of the disc. X-ray diffraction analysis shows decrease in crystalline size with simultaneous increase in dislocation density for five-turn HPT sample with increasing strain from centre to the periphery of the disc. Microstructural analysis using electron back scatter diffraction and transmission electron microscopy indicates extensive grain fragmentation (�55 nm) at the periphery of five-turn sample. The evolution of hardness from centre to the periphery of the disc cannot be explained only on the basis of evolution of grain size and dislocation density. The increase in contribution from solid solution strengthening due to partial dissolution of copper rich nano-clusters is expected to be the underlying cause for increase in the hardness. Thus, evolution of gradient microstructure, texture, and chemistry opens up new vistas for designing functionally graded materials for engineering applications. © 2020 Elsevier B.V.

Item Type:	Journal Article
Publication:	Materials Science and Engineering A
Publisher:	ELSEVIER
Additional Information:	Copyright of this article belongs Elsevier Ltd
Keywords:	Cobalt alloys; Copper alloys; Disks (structural components); Entropy; Functionally graded materials; Hardness; High pressure effects; High resolution transmission electron microscopy; High-entropy alloys; Hydrostatic pressure; Iron alloys; Manganese alloys; Nanoclusters; Nanocrystalline materials; Textures; Torsional stress; X ray powder diffraction, Heterogeneity; High pressure torsions; Shear texture; Strengthening mechanisms; Synchrotron diffraction, Disks (machine components)
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	14 Sep 2020 07:14
Last Modified:	14 Sep 2020 07:14
URI:	http://eprints.iisc.ac.in/id/eprint/65112

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