Role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured Inconel 718 alloy using the laser powder bed fusion technique

Laser powder bed fusion (LPBF) manufactured Inconel 718 superalloy (IN718) parts exhibit inferior creep properties compared to their conventionally manufactured (CM) counterparts due to the unique microstructural features associated with them. In this study, two different heat treatment schedules we...

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Main Authors: Liu, Fei, Radhakrishnan, Jayaraj, Pavan, A. H. V., Ramamurty, Upadrasta
Other Authors: School of Mechanical and Aerospace Engineering
Format: Article
Language:English
Published: 2024
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Online Access:https://hdl.handle.net/10356/180733
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1807332024-10-22T05:05:59Z Role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured Inconel 718 alloy using the laser powder bed fusion technique Liu, Fei Radhakrishnan, Jayaraj Pavan, A. H. V. Ramamurty, Upadrasta School of Mechanical and Aerospace Engineering Institute for Materials Research and Engineering, A*STAR Engineering Post-heat treatment Laves phase Laser powder bed fusion (LPBF) manufactured Inconel 718 superalloy (IN718) parts exhibit inferior creep properties compared to their conventionally manufactured (CM) counterparts due to the unique microstructural features associated with them. In this study, two different heat treatment schedules were employed, to critically examine role of distinct microstructural features associated with LPBF on the creep performance of LPBF IN718. Experimental results reveal that the creep performance is controlled by the Laves and γ′′ phases, as well as the cellular structure. Specially, the effective dissolution of Laves phases that are distributed along the grain and cellular boundaries in the as-fabricated state during solution treatment reduces the cavity nucleation sites and hence, extends the creep lifetime. The release of Nb into the matrix contributes to the precipitation of primary strengthening γ′′ phase during subsequent aging, enhancing the creep resistance. More importantly, the formation of a unique cellular structure with densely distributed γ′′ phase along the cellular boundaries, which exhibits high impediment of dislocation movement and inhibition of crack propagation, results in superior creep performance. The findings of the current study provide an effective heat treatment strategy for achieving high creep performance in LPBF nickel-based superalloys. Agency for Science, Technology and Research (A*STAR) The authors gratefully acknowledge funding from A*STAR, Singapore via the Structural Metals and Alloys Programme (No. A18B1b0061). 2024-10-22T05:05:59Z 2024-10-22T05:05:59Z 2024 Journal Article Liu, F., Radhakrishnan, J., Pavan, A. H. V. & Ramamurty, U. (2024). Role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured Inconel 718 alloy using the laser powder bed fusion technique. Materials Science and Engineering A, 916, 147304-. https://dx.doi.org/10.1016/j.msea.2024.147304 0921-5093 https://hdl.handle.net/10356/180733 10.1016/j.msea.2024.147304 2-s2.0-85204937150 916 147304 en A18B1b0061 Materials Science and Engineering A © 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering
Post-heat treatment
Laves phase
spellingShingle Engineering
Post-heat treatment
Laves phase
Liu, Fei
Radhakrishnan, Jayaraj
Pavan, A. H. V.
Ramamurty, Upadrasta
Role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured Inconel 718 alloy using the laser powder bed fusion technique
description Laser powder bed fusion (LPBF) manufactured Inconel 718 superalloy (IN718) parts exhibit inferior creep properties compared to their conventionally manufactured (CM) counterparts due to the unique microstructural features associated with them. In this study, two different heat treatment schedules were employed, to critically examine role of distinct microstructural features associated with LPBF on the creep performance of LPBF IN718. Experimental results reveal that the creep performance is controlled by the Laves and γ′′ phases, as well as the cellular structure. Specially, the effective dissolution of Laves phases that are distributed along the grain and cellular boundaries in the as-fabricated state during solution treatment reduces the cavity nucleation sites and hence, extends the creep lifetime. The release of Nb into the matrix contributes to the precipitation of primary strengthening γ′′ phase during subsequent aging, enhancing the creep resistance. More importantly, the formation of a unique cellular structure with densely distributed γ′′ phase along the cellular boundaries, which exhibits high impediment of dislocation movement and inhibition of crack propagation, results in superior creep performance. The findings of the current study provide an effective heat treatment strategy for achieving high creep performance in LPBF nickel-based superalloys.
author2 School of Mechanical and Aerospace Engineering
author_facet School of Mechanical and Aerospace Engineering
Liu, Fei
Radhakrishnan, Jayaraj
Pavan, A. H. V.
Ramamurty, Upadrasta
format Article
author Liu, Fei
Radhakrishnan, Jayaraj
Pavan, A. H. V.
Ramamurty, Upadrasta
author_sort Liu, Fei
title Role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured Inconel 718 alloy using the laser powder bed fusion technique
title_short Role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured Inconel 718 alloy using the laser powder bed fusion technique
title_full Role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured Inconel 718 alloy using the laser powder bed fusion technique
title_fullStr Role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured Inconel 718 alloy using the laser powder bed fusion technique
title_full_unstemmed Role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured Inconel 718 alloy using the laser powder bed fusion technique
title_sort role of the γ′′ precipitation at the cell boundaries in enhancing the creep resistance of additively manufactured inconel 718 alloy using the laser powder bed fusion technique
publishDate 2024
url https://hdl.handle.net/10356/180733
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