PSI - Issue 17

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000

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ScienceDirect

Procedia Structural Integrity 17 (2019) 138–145

ICSI 2019 The 3rd International Conference on Structural Integrity Notch fatigue behavior of Inconel 718 produced by selective laser melting Radomila Konečná a , Gianni Nicoletto b *, Enrica Riva b a University of Žilina, Faculty of Mechanical Engineering, Department of Materials Engineering, Univerzitná 8215/1, 010 26 Žilina, Slovakia b University of Parma, department of Engineering and Architecture, Parco Area della Scienze 181/A, 43124 Parma, Italy Inconel 718 is widely used in hot structures of jet engines because of its excellent mechanical properties at high temperatures. Recently, customized parts of complex geometry are increasingly fabricated by Selective Laser Melting (SLM) of Inconel 718 powder. This contribution investigates the still largely unexplored topic of the combined influence of notches and as-built surfaces on the fatigue strength of SLM Inconel 718 parts. An innovative fatigue test method using miniature notched specimens tested in cyclic plane bending is adopted. Four sets of specimens, each with a different orientation of the notch surface with respect to the build axis, are fabricated with a commercial SLM system, heat treated and fatigue tested. The fatigue results show the directional nature of the as built notch effect. The link between surface quality of the notched specimens and their layer-wise fabrication is determined by a metallographic investigation. ICSI 2019 The 3rd International Conference on Structural Integrity Notch fatigue behavior of Inconel 718 produced by selective laser melting Radomila Konečná a , Gianni Nicoletto b *, Enrica Riva b a University of Žilina, Faculty of M chanical Engi eering, Department of Materi ls Engineering, Univ rzitná 8215/1, 010 26 Žilina, Slovakia b University of Parma, department of Engineering and Architecture, Parco Area della Scienze 181/A, 43124 Parma, Italy Abstract Inconel 718 is widely used in hot structures of jet engines because of its excellent mechanical properties at high temperatures. Recently, customized parts of complex geometry are increasingly fabricated by Selective Laser Melting (SLM) of Inconel 718 powder. This contribution investigates the still largely unexplored topic of the combined influence of notches and as-built surfaces on the fatigue strength of SLM I conel 718 parts. An innovative fatigue test method using miniatur notched sp cimens tested in cyclic plane bending is adopted. Four sets of specimens, each with a different orientation of the notch surface with respect to the buil axis, are fabricated with a commercial SLM system, heat treated and fatigue tested. The fatigue results show the directional nature of the as built notch effect. The link between surface quality of the notched specimens and their layer-wise fabrication is determined by a metallographic investigation. Abstract

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers.

Keywords: selective laser melting SLM, Inconel 718, notch fatigue, as-built surface quality, miniature specimen. Keywords: selective laser melting SLM, Inconel 718, notch fatigue, as-built surface quality, miniature specimen.

1. Introduction Selective laser melting (SLM) is an additive manufacturing technology that uses 3D CAD part data as a digital source and fabricates it from a metal powder without the need for part-speci fi c tooling. SLM systems currently 1. Introduction Selective laser melting (SLM) is an additive manufacturing technology that uses 3D CAD part data as a digital source and fabricates it from a metal powder without the need for part-speci fi c tooling. SLM systems currently

* Corresponding author. Tel.: +39-0521-905884; fax: +39-0521-905715. E-mail address: gianni.nicoletto@unipr.it * Correspon ing author. Tel.: +39-0521-905884; fax: +39-0521-905715. E-mail address: gianni.nicoletto@unipr.it

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers.

2452-3216  2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ICSI 2019 organizers. 10.1016/j.prostr.2019.08.019