Abstract
Additive manufacturing (AM) allows for the fabrication of complex parts via layer-by-layer melting of metal powder. Laser powder-bed AM processes use a variety of process parameters including beam power, beam velocity, and hatch spacing to control melting. Alterations to these parameters have often been attempted to reduce porosity, for example, but less work has been done to on comprehensive effects of process parameter modifications. This study looks at the effects of altering these parameters on microstructure, porosity, and mechanical performance of Inconel 718. The results showed that process parameter modifications that result in porosity formation can significantly reduce fatigue life, while microstructure changes were minimal and had little effect on tensile properties. The precipitate structure was not found to be changed significantly. These results can inform future process parameter modifications, as well as heat treatments to optimize mechanical properties.
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References
R. Cunningham, S.P. Narra, T. Ozturk, J. Beuth, and A.D. Rollett, Evaluating the Effect of Processing Parameters on Porosity in Electron Beam Melted Ti-6Al-4V via Synchrotron X-ray Microtomography, JOM, 2016, 68(3), p 765–771
J.C. Fox, S.P. Moylan, and B.M. Lane, Effect of Process Parameters on the Surface Roughness of Overhanging Structures in Laser Powder Bed Fusion Additive Manufacturing, Proc. CIRP, 2016, 45, p 131–134
A. Vasinonta and J. Beuth, Process Maps for Controlling Residual Stress and Melt Pool Size in Laser-Based SFF Processes. in Proceedings of 2000 Solid Freeform Fabrication Symposium, 2000, pp. 200–208
J.B. Joy Gockel, Understanding Ti-6Al-4V Microstructure Control in Additive Manufacturing via Process Maps. in Solid Freeform Fabrication Symposium, 2013, p. 666
A. Cruzado et al., Multiscale Modeling of the Mechanical Behavior of IN718 Superalloy Based on Micropillar Compression and Computational Homogenization, Acta Mater., 2015, 98, p 242–253
Y. Tian et al., Rationalization of Microstructure Heterogeneity in INCONEL 718 Builds Made by the Direct Laser Additive Manufacturing Process, Metall. Mater. Trans. A. Phys. Metall Mater. Sci., 2014, 45(10), p 4470–4483
P. Promoppatum et al., Numerical Modeling and Experimental Validation of Thermal History and Microstructure for Additive Manufacturing of an Inconel 718 product, Prog. Addit. Manuf., 2018, 3, p 15–32. https://doi.org/10.1007/s40964-018-0039-1
M.B. Henderson, D. Arrell, R. Larsson, M. Heobel, and G. Marchant, Nickel Based Superalloy Welding Practices for Industrial Gas Turbine Applications, Sci. Technol. Weld. Join., 2004, 9(1), p 13–21
P.A. Morton, J. Mireles, H. Mendoza, P.M. Cordero, M. Benedict, and R.B. Wicker, Enhancement of Low-Cycle Fatigue Performance From Tailored Microstructures Enabled by Electron Beam Melting Additive Manufacturing Technology, J. Mech. Des., 2015, 137(11), p 111412
R. Cunningham, S.P. Narra, C. Montgomery, J. Beuth, and A.D. Rollett, Synchrotron-Based X-ray Microtomography Characterization of the Effect of Processing Variables on Porosity Formation in Laser Power-Bed Additive Manufacturing of Ti-6Al-4V, JOM., 2017, 69(3), p 2–7. https://doi.org/10.1007/s11837-016-2234-1
M. Tang, P.C. Pistorius, and J.L. Beuth, Prediction of Lack-of-Fusion Porosity for Powder Bed Fusion, Addit. Manuf., 2017, 14, p 39–48
AMS2774E, Heat Treatment Wrought Nickel Alloy and Cobalt Alloy Parts. SAE International, 2016.
ASTME8/E8M-13, Standard Test Methods for Tension Testing of Metallic Materials BT—Standard Test Methods for Tension Testing of Metallic Materials. ASTM International, West Conshohocken, PA, 2013.
ASTME466-15, Standard Practice for Conducting Force Controlled Constant Amplitude Axial Fatigue Tests of Metallic Materials BT—Standard Practice for Conducting Force Controlled Constant Amplitude Axial Fatigue Tests of Metallic Materials. ASTM International, West Conshohocken, PA, 2015.
F. De Carlo, X. Xiao, and C. Jacobsen, Research Papers TomoPy: A Framework for the Analysis of Synchrotron Tomographic Data Research Papers. 2014, pp. 1188–1193
E.A. Lass et al., Formation of the Ni3Nb δ-Phase in Stress-Relieved Inconel 625 Produced via Laser Powder-Bed Fusion Additive Manufacturing, Metall. Mater. Trans. A Phys. Metall. Mater. Sci., 2017, 48(11), p 5547–5558
B. Farber et al., Correlation of Mechanical Properties to Microstructure in Metal Laser Sintering Inconel 718, Mater. Sci. Eng. A, 2018, 712, p 539–547
X. Zhao, J. Chen, X. Lin, and W. Huang, Study on Microstructure and Mechanical Properties of Laser Rapid Forming Inconel 718, Mater. Sci. Eng., A, 2008, 478(1-2), p 119–124
Acknowledgments
The authors acknowledge the support of the NextManufacturing Center at CMU for funding the build and materials. The authors gratefully acknowledge the help of Brian Fisher in building the samples investigated in this study, along with other help in designing the experiments. This research used resources of the Advanced Photon Source (APS), a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. We also thank Xianghui Xiao for facilitating the μXCT measurements at the 2BM beamline at APS.
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Kantzos, C., Pauza, J., Cunningham, R. et al. An Investigation of Process Parameter Modifications on Additively Manufactured Inconel 718 Parts. J. of Materi Eng and Perform 28, 620–626 (2019). https://doi.org/10.1007/s11665-018-3612-3
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DOI: https://doi.org/10.1007/s11665-018-3612-3