Improving fatigue behaviour of additively manufactured Scalmalloy® using laser shock peening

Scalmalloy®, an Al–Mg-Sc based alloy tailored for additive manufacturing, is increasingly used in aerospace and high-performance engineering applications due to its high specific strength, stiffness and comparable density as other aluminum alloys. However, fatigue performance of as-built Scalmalloy®...

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Main Authors: Niroj Maharjan, Yoshio Mizuta, Kiyotaka Masaki, Satoshi Tamaki, Yuji Sano, Tomonao Hosokai, Andrew Ang
Format: Article
Language:English
Published: Elsevier 2025-07-01
Series:Journal of Materials Research and Technology
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Online Access:http://www.sciencedirect.com/science/article/pii/S2238785425016916
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author Niroj Maharjan
Yoshio Mizuta
Kiyotaka Masaki
Satoshi Tamaki
Yuji Sano
Tomonao Hosokai
Andrew Ang
author_facet Niroj Maharjan
Yoshio Mizuta
Kiyotaka Masaki
Satoshi Tamaki
Yuji Sano
Tomonao Hosokai
Andrew Ang
author_sort Niroj Maharjan
collection DOAJ
description Scalmalloy®, an Al–Mg-Sc based alloy tailored for additive manufacturing, is increasingly used in aerospace and high-performance engineering applications due to its high specific strength, stiffness and comparable density as other aluminum alloys. However, fatigue performance of as-built Scalmalloy® parts could deteriorate rapidly due to its heterogeneous microstructure and inherent surface defects. While heat treatments are commonly employed to enhance its properties, there is an opportunity to enhance the properties further using mechanical surface treatments such as laser shock peening (LSP). This study examines the impact of LSP with a pulse energy as low as 2.4 mJ on the microstructure and fatigue behavior of laser powder bed fusion (L-PBF) Scalmalloy®. Cross-sectional analyses revealed LSP reduced grain size near the surface from ∼4.0 μm to ∼2.8 μm and increased the geometrically necessary dislocation (GND) density by almost 1.5 times. Maximum compressive residual stress (CRS) close to 500 MPa was introduced on the top surface and compression penetrated to a depth of 250 μm. These microstructural modifications and CRS contribute to fatigue limit increment from 100 MPa to 175 MPa. The findings underscore the effectiveness of LSP as a post-processing technique for Scalmalloy® offering a viable pathway to improve the durability of critical aeronautics and space components operating under cyclic loading conditions.
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spelling doaj-art-e631aa31560948c288ba1c3a273fb0162025-08-20T03:17:27ZengElsevierJournal of Materials Research and Technology2238-78542025-07-01373424343310.1016/j.jmrt.2025.07.033Improving fatigue behaviour of additively manufactured Scalmalloy® using laser shock peeningNiroj Maharjan0Yoshio Mizuta1Kiyotaka Masaki2Satoshi Tamaki3Yuji Sano4Tomonao Hosokai5Andrew Ang6School of Engineering, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia; Corresponding author.Sanken, The University of Osaka, Ibaraki, Osaka, 567-0047, JapanSaitama Institute of Technology, Fukaya, Saitama, 369-0293, JapanSanken, The University of Osaka, Ibaraki, Osaka, 567-0047, JapanSanken, The University of Osaka, Ibaraki, Osaka, 567-0047, Japan; Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8585, JapanSanken, The University of Osaka, Ibaraki, Osaka, 567-0047, JapanSchool of Engineering, Swinburne University of Technology, Hawthorn, VIC, 3122, AustraliaScalmalloy®, an Al–Mg-Sc based alloy tailored for additive manufacturing, is increasingly used in aerospace and high-performance engineering applications due to its high specific strength, stiffness and comparable density as other aluminum alloys. However, fatigue performance of as-built Scalmalloy® parts could deteriorate rapidly due to its heterogeneous microstructure and inherent surface defects. While heat treatments are commonly employed to enhance its properties, there is an opportunity to enhance the properties further using mechanical surface treatments such as laser shock peening (LSP). This study examines the impact of LSP with a pulse energy as low as 2.4 mJ on the microstructure and fatigue behavior of laser powder bed fusion (L-PBF) Scalmalloy®. Cross-sectional analyses revealed LSP reduced grain size near the surface from ∼4.0 μm to ∼2.8 μm and increased the geometrically necessary dislocation (GND) density by almost 1.5 times. Maximum compressive residual stress (CRS) close to 500 MPa was introduced on the top surface and compression penetrated to a depth of 250 μm. These microstructural modifications and CRS contribute to fatigue limit increment from 100 MPa to 175 MPa. The findings underscore the effectiveness of LSP as a post-processing technique for Scalmalloy® offering a viable pathway to improve the durability of critical aeronautics and space components operating under cyclic loading conditions.http://www.sciencedirect.com/science/article/pii/S2238785425016916Laser shock peeningScalmalloy®FatigueResidual stressLaser powder bed fusion
spellingShingle Niroj Maharjan
Yoshio Mizuta
Kiyotaka Masaki
Satoshi Tamaki
Yuji Sano
Tomonao Hosokai
Andrew Ang
Improving fatigue behaviour of additively manufactured Scalmalloy® using laser shock peening
Journal of Materials Research and Technology
Laser shock peening
Scalmalloy®
Fatigue
Residual stress
Laser powder bed fusion
title Improving fatigue behaviour of additively manufactured Scalmalloy® using laser shock peening
title_full Improving fatigue behaviour of additively manufactured Scalmalloy® using laser shock peening
title_fullStr Improving fatigue behaviour of additively manufactured Scalmalloy® using laser shock peening
title_full_unstemmed Improving fatigue behaviour of additively manufactured Scalmalloy® using laser shock peening
title_short Improving fatigue behaviour of additively manufactured Scalmalloy® using laser shock peening
title_sort improving fatigue behaviour of additively manufactured scalmalloy r using laser shock peening
topic Laser shock peening
Scalmalloy®
Fatigue
Residual stress
Laser powder bed fusion
url http://www.sciencedirect.com/science/article/pii/S2238785425016916
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