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Modelling plastic deformation in a single-crystal nickel-based superalloy using discrete dislocation dynamics

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posted on 2016-11-04, 13:25 authored by Bing Lin, Minsheng Huang, Farukh Farukh, Anish RoyAnish Roy, Vadim SilberschmidtVadim Silberschmidt, Liguo Zhao
Background: Nickel-based superalloys are usually exposed to high static or cyclic loads in non-ambient environment, so a reliable prediction of their mechanical properties, especially plastic deformation, at elevated temperature is essential for improved damage-tolerance assessment of components. Methods: In this paper, plastic deformation in a single-crystal nickel-based superalloy CMSX4 at elevated temperature was modelled using discrete dislocation dynamics (DDD). The DDD approach was implemented using a representative volume element with explicitly-introduced precipitate and periodic boundary condition. The DDD model was calibrated using stress-strain response predicted by a crystal plasticity model, validated against tensile and cyclic tests at 850°C for <001> and <111> crystallographic orientations, at a strain rate of 1/s. Results: The DDD model was capable to capture the global stress-strain response of the material under both monotonic and cyclic loading conditions. Considerably higher dislocation density was obtained for the <111> orientation, indicating more plastic deformation and much lower flow stress in the material, when compared to that for <001> orientation. Dislocation lines looped around the precipitate, and most dislocations were deposited on the surface of precipitate, forming a network of dislocation lines. Simple unloading resulted in a reduction of dislocation density. Conclusions: Plastic deformation in metallic materials is closely related to dynamics of dislocations, and the DDD approach can provide a more fundamental understanding of crystal plasticity and the evolution of heterogeneous dislocation networks, which is useful when considering such issues as the onset of damage in the material during plastic deformation.

Funding

The work was funded by the EPSRC (Grants EP/K026844/1 and EP/M000966/1) of the UK. The crystal plasticity UMAT was originally developed and calibrated against the experimental data by Professor Esteban Busso, Professor Noel O’Dowd and their associates while they were with the Imperial College, London. The research leading to these results also received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement No. PIRSES-GA-2013-610547 TAMER.

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

Mechanics of Advanced Materials and Modern Processes

Volume

2

Issue

6

Citation

LIN, B. ... et al, 2016. Modelling plastic deformation in a single-crystal nickel-based superalloy using discrete dislocation dynamics. Mechanics of Advanced Materials and Modern Processes, 2(6).

Publisher

SpringerOpen

Version

  • AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by/4.0/

Acceptance date

2016-10-08

Publication date

2016-11-15

Copyright date

2016

Notes

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

ISSN

2198-7874

Language

  • en