Paper Titles
Preface
Rib Geometry in FDM of Light Alloys
p.1
Machine Learning Topography Prediction and Optimization in Maskless Grayscale Laser Lithography
p.11
A Comparative Analysis of LPBF Process Maps for S2 and S6 Grades Tool Steel
p.21
Laser Powder Bed Fusion of Inconel® 625: Guidelines for Robust Parameter Selection Toward Optimal Quality Parts
p.31
Numerical Modelling of Directed Energy Deposition and Experimental Validation Based on Digital Image Correlation
p.41
Advanced Characterization of Flexible Auxetic Resin Lattice Structures Produced by Stereolithography
p.53
Evaluation of Sla Biocompatible Resins Properties for Use as Dielectric Layers in 3D Printed Capacitive Force Sensors
p.65
A Physics Informed Machine Learning Framework towards Density Prediction of Additively Manufactured Components
p.73

Laser Powder Bed Fusion of Inconel® 625: Guidelines for Robust Parameter Selection Toward Optimal Quality Parts

Article Preview
View Pdf By email

Abstract:

Producing INCONEL® 625 (IN625) components by laser powder bed fusion (PBF-LB) demands a careful selection of process parameters to concurrently ensure high densification, stable microstructural features, and adequate surface integrity. Previous studies investigated the isolated effect of these parameters or narrow volumetric energy density (VED) ranges, albeit without offering indications on how to simultaneously optimize surface roughness, microhardness, and density. Furthermore, the validity of VED as an input for process optimization is still debated. The present study offers a systematic exploration of the laser power–scan speed (P–v) space over a wide VED interval (33–400 J/mm³) to identify stable and robust process regimes for PBF-LB of IN625. Cylindrical samples built according to dissimilar P–v combinations reveal an extended process window where the properties of interest remain well balanced. Within this region, surface roughness below 10 µm, microhardness near 300 HV1000, and relative density over 99.5% were consistently achieved. Furthermore, distinct P–v combinations sharing the same VED value were confirmed to produce markedly different results, underscoring the limitations of VED as a predictive descriptor. The findings allowed to establish quantitative guidelines for selecting robust P–v conditions, offering a practical foundation for future data-driven or physics-informed multi-objective process optimisation of PBF-LB IN625.

You might also be interested in these eBooks
Additive Manufacturing View Preview

Info:

Periodical:

Key Engineering Materials (Volume 1047)

Pages:

31-40

Online since:

April 2026

Authors:

Gabriele Locatelli*, Mariangela Quarto, Sara Bocchi, Cristian Cappellini, Gianluca D'Urso

Keywords:

Additive Manufacturing, Inconel 625, Powder Bed Fusion, Process Optimization

Export:

RIS, BibTeX

Permissions:

Creative Commons CC BY 4.0

Share:

* - Corresponding Author

References

[1] A. Nowotnik, Nickel-Based Superalloys, in: Reference Module in Materials Science and Materials Engineering, Elsevier, 2016.

DOI: 10.1016/b978-0-12-803581-8.02574-1

Google Scholar

[2] T. Islam, B. Zhao, D. Piccone, R. Bertelsen, D. Lin, Z. (Andy) Fan, J. Klemm-Toole, S. Pan, A holistic corrosion understanding in IN625 alloy based on additive manufacturing history and microstructure modification, Electrochim. Acta, 535 (2025) 146697.

DOI: 10.1016/j.electacta.2025.146697

Google Scholar

[3] J.M. Rakowski, C.P. Stinner, The Use and Performance of Wrought 625 Alloy in Primary Surface Recuperators for Gas Turbine Engines, in: CORROSION 2005, NACE International, 2005: p.1–14.

DOI: 10.5006/c2005-05447

Google Scholar

[4] Z. Tian, C. Zhang, D. Wang, W. Liu, X. Fang, D. Wellmann, Y. Zhao, Y. Tian, A Review on Laser Powder Bed Fusion of Inconel 625 Nickel-Based Alloy, Applied Sciences, 10 (2019) 81.

DOI: 10.3390/app10010081

Google Scholar

[5] M. Karmuhilan, S. Kumanan, A Review on Additive Manufacturing Processes of Inconel 625, J. Mater. Eng. Perform., 31 (2022) 2583–2592.

DOI: 10.1007/s11665-021-06427-3

Google Scholar

[6] M.C. Karia, M.A. Popat, K.B. Sangani, Selective laser melting of Inconel super alloy-a review, in: 2017: p.020013.

DOI: 10.1063/1.4990166

Google Scholar

[7] M.A. Buhairi, F.M. Foudzi, F.I. Jamhari, A.B. Sulong, N.A.M. Radzuan, N. Muhamad, I.F. Mohamed, A.H. Azman, W.S.W. Harun, M.S.H. Al-Furjan, Review on volumetric energy density: influence on morphology and mechanical properties of Ti6Al4V manufactured via laser powder bed fusion, Progress in Additive Manufacturing, 8 (2023) 265–283.

DOI: 10.1007/s40964-022-00328-0

Google Scholar

[8] K. Mumtaz, N. Hopkinson, Top surface and side roughness of Inconel 625 parts processed using selective laser melting, Rapid Prototyp. J., 15 (2009) 96–103.

DOI: 10.1108/13552540910943397

Google Scholar

[9] R. Sheshadri, M. Nagaraj, A. Lakshmikanthan, M.P.G. Chandrashekarappa, D.Y. Pimenov, K. Giasin, R.V.S. Prasad, S. Wojciechowski, Experimental investigation of selective laser melting parameters for higher surface quality and microhardness properties: taguchi and super ranking concept approaches, Journal of Materials Research and Technology, 14 (2021) 2586–2600.

DOI: 10.1016/j.jmrt.2021.07.144

Google Scholar

[10] M.J. Benoit, M. Mazur, M.A. Easton, M. Brandt, Effect of alloy composition and laser powder bed fusion parameters on the defect formation and mechanical properties of Inconel 625, The International Journal of Advanced Manufacturing Technology, 114 (2021) 915–927.

DOI: 10.1007/s00170-021-06957-z

Google Scholar

[11] A. Paraschiv, G. Matache, M.R. Condruz, T.F. Frigioescu, L. Pambaguian, Laser Powder Bed Fusion Process Parameters' Optimization for Fabrication of Dense IN 625, Materials, 15 (2022) 5777.

DOI: 10.3390/ma15165777

Google Scholar

[12] J.-R. Poulin, A. Kreitcberg, P. Terriault, V. Brailovski, Long fatigue crack propagation behavior of laser powder bed-fused inconel 625 with intentionally-seeded porosity, Int. J. Fatigue, 127 (2019) 144–156.

DOI: 10.1016/j.ijfatigue.2019.06.008

Google Scholar

[13] H. Yeung, F.H. Kim, M.A. Donmez, J. Neira, Keyhole pores reduction in laser powder bed fusion additive manufacturing of nickel alloy 625, Int. J. Mach. Tools Manuf., 183 (2022) 103957.

DOI: 10.1016/j.ijmachtools.2022.103957

Google Scholar

[14] R. Yamanoglu, Effect of laser energy density on porosity and microstructural features of Inconel 625 alloy produced by selective laser melting, Journal of Advances in Manufacturing Engineering, (2024) 84–93.

DOI: 10.14744/ytu.jame.2024.00010

Google Scholar

[15] A. Shahrjerdi, M. Karamimoghadam, R. Shahrjerdi, G. Casalino, M. Bodaghi, Optimizing Selective Laser Melting of Inconel 625 Superalloy through Statistical Analysis of Surface and Volumetric Defects, Designs (Basel)., 8 (2024) 87.

DOI: 10.3390/designs8050087

Google Scholar

[16] R.A. Yildiz, O. Gokcekaya, M. Malekan, A holistic analysis of laser powder bed fusion process parameters for Inconel 625 superalloy: microstructural features and mechanical performance, Progress in Additive Manufacturing, (2025).

DOI: 10.1007/s40964-025-01385-x

Google Scholar

[17] M.A. Balbaa, M.A. Elbestawi, J. McIsaac, An experimental investigation of surface integrity in selective laser melting of Inconel 625, The International Journal of Advanced Manufacturing Technology, 104 (2019) 3511–3529.

DOI: 10.1007/s00170-019-03949-y

Google Scholar

[18] C. Guo, S. Li, S. Shi, X. Li, X. Hu, Q. Zhu, R.M. Ward, Effect of processing parameters on surface roughness, porosity and cracking of as-built IN738LC parts fabricated by laser powder bed fusion, J. Mater. Process. Technol., 285 (2020) 116788.

DOI: 10.1016/j.jmatprotec.2020.116788

Google Scholar

[19] S. Li, Q. Wei, Y. Shi, Z. Zhu, D. Zhang, Microstructure Characteristics of Inconel 625 Superalloy Manufactured by Selective Laser Melting, J. Mater. Sci. Technol., 31 (2015) 946–952.

DOI: 10.1016/j.jmst.2014.09.020

Google Scholar

[20] H.R. Javidrad, S. Salemi, Effect of the Volume Energy Density and Heat Treatment on the Defect, Microstructure, and Hardness of L-PBF Inconel 625, Metallurgical and Materials Transactions A, 51 (2020) 5880–5891.

DOI: 10.1007/s11661-020-05992-x

Google Scholar

[21] M. Giovagnoli, G. Silvi, M. Merlin, M.T. Di Giovanni, Optimisation of process parameters for an additively manufactured AlSi10Mg alloy: Limitations of the energy density-based approach on porosity and mechanical properties estimation, Materials Science and Engineering: A, 802 (2021) 140613.

DOI: 10.1016/j.msea.2020.140613

Google Scholar

[22] Y. Huang, T.G. Fleming, S.J. Clark, S. Marussi, K. Fezzaa, J. Thiyagalingam, C.L.A. Leung, P.D. Lee, Keyhole fluctuation and pore formation mechanisms during laser powder bed fusion additive manufacturing, Nat. Commun., 13 (2022) 1170.

DOI: 10.1038/s41467-022-28694-x

Google Scholar

[23] G.V. de Leon Nope, L.I. Perez-Andrade, J. Corona-Castuera, D.G. Espinosa-Arbelaez, J. Muñoz-Saldaña, J.M. Alvarado-Orozco, Study of volumetric energy density limitations on the IN718 mesostructure and microstructure in laser powder bed fusion process, J. Manuf. Process., 64 (2021) 1261–1272.

DOI: 10.1016/j.jmapro.2021.02.043

Google Scholar

[24] R. Zhao, C. Chen, W. Wang, T. Cao, S. Shuai, S. Xu, T. Hu, H. Liao, J. Wang, Z. Ren, On the role of volumetric energy density in the microstructure and mechanical properties of laser powder bed fusion Ti-6Al-4V alloy, Addit. Manuf., 51 (2022) 102605.

DOI: 10.1016/j.addma.2022.102605

Google Scholar

[25] C. Smith, G. Hommer, M. Keeler, J. Gockel, K. Findley, C. Brice, A. Clarke, J. Klemm-Toole, Assessing Volumetric Energy Density as a Predictor of Defects in Laser Powder Bed Fusion 316L Stainless Steel, JOM, 77 (2025) 737–748.

DOI: 10.1007/s11837-024-06946-z

Google Scholar