PSI - Issue 66

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2025) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2025) 000 – 000

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Procedia Structural Integrity 66 (2024) 49–54

8th International Conference on Crack Paths Transient fatigue crack path on AlSi10Mg alloy CT specimens produced by Laser Powder Bed Fusion R. Fernades a , J.S. Jesus a , L.P. Borrego a, b * , J.A.M. Ferreira a , R. Branco a , J.D. Costa a a University of Coimbra, CEMMPRE, ARISE, Department of Mechanical Engineering, Coimbra, Portugal b Polytechnic University of Coimbra, Coimbra Institute of Engineering, Rua Pedro Nunes, 3030-199 Coimbra, Portugal Abstract The Additive Manufacturing process, namely the Laser Powder Bed Fusion, enables the 3D printing of components in Aluminium alloys, such as AlSi10Mg. The Aluminium alloys are widely used in aeronautical and other high-performance engineering applications, whereby it is fundamental the understanding of in-service fatigue behaviour. The current paper is focused on the fatigue crack path of AlSi10Mg aluminium using CT specimens loaded in mode I. The fatigue tests are carried out at ambient temperature and in load control mode. Fatigue crack growth behaviour was studied for three material conditions: as-built, stress relieved and hot isostatic pressed. An improvement in the fatigue crack growth resistance was found for the heat-treated conditions which was attributed to the residual stress relief induced by the heat treatments. The applied heat treatments induced slight microstructural transformations, resulting in a coarser Al-Si supersaturated matrix. The residual stress relief and their subsequent stabilization were the main mechanisms responsible for improving the fatigue crack growth resistance. Fracture crack propagation is predominantly in interlayer mode, but in some cases can occurs intralayer path in consequence of porosities presence. Single overloading promotes a marked line corresponding to crack tip at overload, and a crack deflection, with the transition crack path of one or more deposition layers at overloading moment. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2024 Organizers Keywords: Laser powder bed fusion; Aluminum alloys; Fatigue; Crack path; 8th International Conference on Crack Paths Transient fatigue crack path on AlSi10Mg alloy CT specimens produced by Laser Powder Bed Fusion R. Fernades a , J.S. Jesus a , L.P. Borrego a, b * , J.A.M. Ferreira a , R. Branco a , J.D. Costa a a University of Coimbra, CEMMPRE, ARISE, Department of Mechanical Engineering, Coimbra, Portugal b Polytechnic University of Coimbra, Coimbra Institute of Engineering, Rua Pedro Nunes, 3030-199 Coimbra, Portugal Abstract The Additive Manufacturing process, namely the Laser Powder Bed Fusion, enables the 3D printing of components in Aluminium alloys, such as AlSi10Mg. The Aluminium alloys are widely used in aeronautical and other high-performance engineering applications, whereby it is fundamental the understanding of in-service fatigue behaviour. The current paper is focused on the fatigue crack path of AlSi10Mg aluminium using CT specimens loaded in mode I. The fatigue tests are carried out at ambient temperature and in load control mode. Fatigue crack growth behaviour was studied for three material conditions: as-built, stress relieved and hot isostatic pressed. An improvement in the fatigue crack growth resistance was found for the heat-treated conditions which was attributed to the residual stress relief induced by the heat treatments. The applied heat treatments induced slight microstructural transformations, resulting in a coarser Al-Si supersaturated matrix. The residual stress relief and their subsequent stabilization were the main mechanisms responsible for improving the fatigue crack growth resistance. Fracture crack propagation is predominantly in interlayer mode, but in some cases can occurs intralayer path in consequence of porosities presence. Single overloading promotes a marked line corresponding to crack tip at overload, and a crack deflection, with the transition crack path of one or more deposition layers at overloading moment. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2024 Organizers Keywords: Laser powder bed fusion; Aluminum alloys; Fatigue; Crack path;

* Corresponding author. Tel.: +0-000-000-0000 . E-mail address: borrego@isec.pt * Corresponding author. Tel.: +0-000-000-0000 . E-mail address: borrego@isec.pt

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2024 Organizers 2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2024 Organizers

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2024 Organizers 10.1016/j.prostr.2024.11.054