Grain disintegration and dynamic recrystallization during impact tests of additively manufactured nickel-based alloy 718

The high-temperature dynamic mechanical response of Alloy 718 produced via laser-powder bed fusion (LPBF) was investigated through compressive Split-Hopkinson Pressure Bar (SHPB) tests. Simulating the typical service conditions of Alloy 718, the tests were conducted at temperatures ranging from 298 ...

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Main Authors: Anjali Sankar, Manjaiah M, Thomas McCarthy, Jubert Pasco, Stan Kristian Ejera, Clodualdo Aranas
Format: Article
Language:English
Published: Elsevier 2024-11-01
Series:Journal of Materials Research and Technology
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Online Access:http://www.sciencedirect.com/science/article/pii/S223878542402427X
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author Anjali Sankar
Manjaiah M
Thomas McCarthy
Jubert Pasco
Stan Kristian Ejera
Clodualdo Aranas
author_facet Anjali Sankar
Manjaiah M
Thomas McCarthy
Jubert Pasco
Stan Kristian Ejera
Clodualdo Aranas
author_sort Anjali Sankar
collection DOAJ
description The high-temperature dynamic mechanical response of Alloy 718 produced via laser-powder bed fusion (LPBF) was investigated through compressive Split-Hopkinson Pressure Bar (SHPB) tests. Simulating the typical service conditions of Alloy 718, the tests were conducted at temperatures ranging from 298 K to 773 K and at strain rates of 1000 s−1 to 1500 s−1. Phenomenological material constitutive models, such as the modified versions of Johnson-Cook and Hensel-Spittel models, were developed based on the SHPB test results. Analysis of microstructural evolution under impact conditions highlighted that columnar grains with high Schmid factors tend to undergo preferential activation and dislocation pile-up. This process leads to the formation of adiabatic shear bands, grain disintegration, and intense lattice rotation, particularly at higher strain rates. Furthermore, increasing the dynamic deformation temperature facilitates the activation of discontinuous dynamic recrystallization (DRX), with strain accumulation promoting localized grain nucleation along heavily dislocated dendritic boundaries. Recognizing the limitations of phenomenological material constitutive models in accurately representing the underlying microstructural evolution, an artificial neural network (ANN)-based constitutive model employing a three-layer backpropagation learning algorithm was implemented, reducing the Average Absolute Relative Error (AARE) to 0.17%.
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issn 2238-7854
language English
publishDate 2024-11-01
publisher Elsevier
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series Journal of Materials Research and Technology
spelling doaj-art-e14280159b714e5bb945dbe0bd1c79b32025-08-20T02:39:03ZengElsevierJournal of Materials Research and Technology2238-78542024-11-01334844485710.1016/j.jmrt.2024.10.157Grain disintegration and dynamic recrystallization during impact tests of additively manufactured nickel-based alloy 718Anjali Sankar0Manjaiah M1Thomas McCarthy2Jubert Pasco3Stan Kristian Ejera4Clodualdo Aranas5Mechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, CanadaMechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, Canada; Mechanical Engineering, National Institute of Technology Warangal, Telangana, India; Corresponding author. Mechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, Canada.Mechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, CanadaMechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, CanadaDepartment of Mining, Metallurgical and Materials Engineering, University of the Philippines, Quezon City, PhilippinesMechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, Canada; Department of Mining, Metallurgical and Materials Engineering, University of the Philippines, Quezon City, Philippines; Corresponding author. Mechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, Canada.The high-temperature dynamic mechanical response of Alloy 718 produced via laser-powder bed fusion (LPBF) was investigated through compressive Split-Hopkinson Pressure Bar (SHPB) tests. Simulating the typical service conditions of Alloy 718, the tests were conducted at temperatures ranging from 298 K to 773 K and at strain rates of 1000 s−1 to 1500 s−1. Phenomenological material constitutive models, such as the modified versions of Johnson-Cook and Hensel-Spittel models, were developed based on the SHPB test results. Analysis of microstructural evolution under impact conditions highlighted that columnar grains with high Schmid factors tend to undergo preferential activation and dislocation pile-up. This process leads to the formation of adiabatic shear bands, grain disintegration, and intense lattice rotation, particularly at higher strain rates. Furthermore, increasing the dynamic deformation temperature facilitates the activation of discontinuous dynamic recrystallization (DRX), with strain accumulation promoting localized grain nucleation along heavily dislocated dendritic boundaries. Recognizing the limitations of phenomenological material constitutive models in accurately representing the underlying microstructural evolution, an artificial neural network (ANN)-based constitutive model employing a three-layer backpropagation learning algorithm was implemented, reducing the Average Absolute Relative Error (AARE) to 0.17%.http://www.sciencedirect.com/science/article/pii/S223878542402427XAlloy 718LPBFDynamic mechanical responseConstitutive modellingSHPB
spellingShingle Anjali Sankar
Manjaiah M
Thomas McCarthy
Jubert Pasco
Stan Kristian Ejera
Clodualdo Aranas
Grain disintegration and dynamic recrystallization during impact tests of additively manufactured nickel-based alloy 718
Journal of Materials Research and Technology
Alloy 718
LPBF
Dynamic mechanical response
Constitutive modelling
SHPB
title Grain disintegration and dynamic recrystallization during impact tests of additively manufactured nickel-based alloy 718
title_full Grain disintegration and dynamic recrystallization during impact tests of additively manufactured nickel-based alloy 718
title_fullStr Grain disintegration and dynamic recrystallization during impact tests of additively manufactured nickel-based alloy 718
title_full_unstemmed Grain disintegration and dynamic recrystallization during impact tests of additively manufactured nickel-based alloy 718
title_short Grain disintegration and dynamic recrystallization during impact tests of additively manufactured nickel-based alloy 718
title_sort grain disintegration and dynamic recrystallization during impact tests of additively manufactured nickel based alloy 718
topic Alloy 718
LPBF
Dynamic mechanical response
Constitutive modelling
SHPB
url http://www.sciencedirect.com/science/article/pii/S223878542402427X
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