Cyclic plasticity and fatigue damage of CrMnFeCoNi high entropy alloy fabricated by laser powder-bed fusion
File(s)2007.07043v1.pdf (9.43 MB)
Accepted version
Author(s)
Type
Journal Article
Abstract
The CrMnFeCoNi high-entropy alloy is highly printable and holds great potential for structural applications. However, no significant discussions on cyclic plasticity and fatigue damage in previous studies. This study provides significant insights into the link between print processes, solidification microstructure, cyclic plasticity and fatigue damage evolution in the alloy fabricated by laser powder bed fusion. Thermodynamics-based predictions (validated by scanning transmission electron microscopy (STEM) energy dispersive X-ray spectroscopy (EDX)) showed that Cr, Co and Fe partition to the core of the solidification cells, whilst Mn and Ni to the cell boundaries in all considered print parameters. Both dislocation slip and deformation twinning were found to be responsible for plastic deformation under monotonic loading. However, the former was found to be the single dominant mechanism for cyclic plasticity. The surface finish helped to substantially delay the crack initiation and cause lack-of-fusion porosity to be the main source of crack initiation. Most significantly, the scan strategies significantly affect grain arrangements and grain dimensions, leading to noticeable effects on fatigue crack propagation; in particular, the highest resistance crack propagation was seen in the meander scan strategy with 0° rotation thanks to the most columnar grains and the smallest spacing of grain boundaries along the crack propagation path.
Editor(s)
Mohammadi, Mohsen
Date Issued
2020-12
Date Acceptance
2020-08-28
Citation
Additive Manufacturing, 2020, 36, pp.1-15
ISSN
2214-8604
Publisher
Elsevier
Start Page
1
End Page
15
Journal / Book Title
Additive Manufacturing
Volume
36
Copyright Statement
© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Engineering & Physical Science Research Council (E
Identifier
https://www.sciencedirect.com/science/article/pii/S2214860420309568?via%3Dihub
Grant Number
EP/K503733/1
Subjects
physics.app-ph
physics.app-ph
cond-mat.mtrl-sci
0910 Manufacturing Engineering
Publication Status
Published online
Date Publish Online
2020-09-11