PSI - Issue 46

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 46 (2023) 119–124

© 2023 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 ICSID 2021 Organizers Abstract The axial loading fatigue tests with stress ratios of -1 and 0.1 at 650 °C were performed to examine the fatigue failure mechanism of a Ni-based superalloy manufactured by selective laser melting (SLM) in the long life regime at high temperature. As a result, the interior cracking with a typical circular rough area (CDA) is a predominant failure mode. Especially in the very high cycle fatigue regime, the CDA is mainly consisted of the facets with distinct grain misorientation. Combined with the analysis of electron backscatter diffraction, the formation of facet is greatly related to the slipping within the grains located in the highest shear stress plane, especially under the assistance of microstructural defects. The interior cracking mechanism of SLM Ni-based superalloy in the long life regime at elevated temperature is elucidated. © 2021 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 ICSID 2021 Organizers Keywords: Laser treatment; Electron backscatter diffraction; Superalloy; High temperature; Interior fatigue cracking 1. Introduction Additive manufacturing (AM) Ni-based superalloys have been tried to use in aerospace and power industries due to the fine grain, uniform structure and excellent mechanical properties (Watring et al. (2020), Rezaei et al. (2020), Mlikota et al. (2021)). The related fatigue properties in traditional fields (i.e., low cycle fatigue (LCF) and high cycle fatigue (HCF)), involved with manufacturing mode, phase effect, heat treatment effects, notch geometries, surface modification, defect (e.g., porosity) size, etc. (Balachandramurthi et al. (2018), Xu et al. (2018), Witkin et al. (2019), Popovich et al. (2020), Cheloee et al. (2021)), have been investigated. However, in the very high cycle fatigue (VHCF) 5th International Conference on Structural Integrity and Durability Effect of high temperature on failure behavior of additively manufactured superalloy under fatigue W. Li*, T.Y. Hu, R. Sun, Y.C. Zhang Beijing Institute of Technology, School of Mechanical Engineering, No. 5, South Street, Zhongguancun, Haidian District, Beijing, China

* Corresponding author. Tel.: +86 010 68918730 ; fax: +86 010 68918730 . E-mail address: lliw@bit.edu.cn

2452-3216 © 2021 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 ICSID 2021 Organizers

2452-3216 © 2023 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 ICSID 2021 Organizers 10.1016/j.prostr.2023.06.020