Exploring mechanical behavior at interfaces of laser powder bed fusion (LPBF) deposits on wrought Inconel 718: an indentation-based approach
ISSN: 1355-2546
Article publication date: 10 September 2024
Issue publication date: 18 November 2024
Abstract
Purpose
This study used an indentation-based mechanical testing framework for the mechanical characterization of laser powder bed fusion (LPBF) processed Inconel 718 on a wrought Inconel 718 substrate. The purpose of the paper is to investigate the effectiveness of the indentation-based approach for localized mechanical evaluation.
Design/methodology/approach
The LPBF-processed wrought substrate was sectioned into three sections for microstructural and mechanical characterization. A 3D heat source model was used for the thermal analysis of the interface region. The developed interface region is probed using the Knoop hardness indenter in different orientations to determine the textural anisotropy and mechanical behavior of the region.
Findings
LPBF process develops a melted interface zone (MIZ) at the deposition-substrate interface. The MIZ exhibited a coarse grain structure region along with a larger primary dendritic arm spacing (PDAS), signifying a slower cooling rate. FE modeling of the LPBF process reveals heat accumulation in the substrate along with intrinsic heat treatment (IHT) induced due to layer-wise processing. The obtained yield locus shows strong anisotropy in the deposition region, whereas reduced anisotropy with a nearly uniform ellipse locus for the MIZ regions. This reduced anisotropy is attributable to IHT and heat accumulation in the substrate.
Originality/value
An alternative localized mechanical characterization tool has been investigated in this work. The approach proved sensitive to thermal variations during LPBF processing in an isolated region which extends its suitability to variable geometry parts. Moreover, the approach could serve as a screening tool for parts made from dissimilar metals.
Keywords
Acknowledgements
Funding: This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.
Declaration of competing interest: The authors declare no competing interests that could have influenced the work reported in this paper.
Ethical approval: There are no human subjects involved in the article.
Citation
Shrivastava, A., S., A.K. and Rao, S. (2024), "Exploring mechanical behavior at interfaces of laser powder bed fusion (LPBF) deposits on wrought Inconel 718: an indentation-based approach", Rapid Prototyping Journal, Vol. 30 No. 10, pp. 2174-2189. https://doi.org/10.1108/RPJ-02-2024-0075
Publisher
:Emerald Publishing Limited
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