An Investigation of Process Parameter Modifications on Additively Manufactured Inconel 718 Parts

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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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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Correspondence to Anthony Rollett.

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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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Keywords

  • additive manufacturing
  • Inconel 718
  • mechanical properties
  • microstructure
  • process parameters
  • selective laser melting