Abstract
Electron beam powder bed fusion (E-PBF) can produce nickel-based superalloy components with minimal cracking and post-processing. This is due to the reduced thermal gradients and high print temperatures accessible through innovative beam scanning strategies compared to other AM processes. However, variations in thermal signature along the build direction inherent in alloys printed using E-PBF can drive significant changes in the microstructure and associated mechanical properties. In this work, through complementary local property measurements we observed a 127 – 145% increase in mean elastic modulus and 7–9% increase in mean hardness, as a function of build height, of an as-fabricated non-weldable Ni-based superalloy, Inconel 738. These properties were attributed primarily to variations in the γ′ character with build height, revealed through a multi-scale microstructural characterisation. The results highlight the influence of the thermal signatures on the microstructural-property relationships of E-PBF Inconel 738.
| Original language | English |
|---|---|
| Article number | 102121 |
| Journal | Additive Manufacturing |
| Volume | 46 |
| DOIs | |
| State | Published - Oct 2021 |
| Externally published | Yes |
Funding
The authors acknowledge Drs. Vijay Bhatia, Takanori Sato, Hongwei Liu, Magnus Garbrecht, Ranming Niu, Andy H. Wang, and Ms. Ashalatha I.K. Pillai, at the University of Sydney for their technical support. Mr. Edward Whitelock's (UNSW Sydney) preparation of overview optical micrographs (Fig. 5) is acknowledged. The authors further acknowledge the facilities, and the scientific and technical assistance of the Microscopy Australia node at the University of Sydney (Sydney Microscopy & Microanalysis). This research was sponsored by the Department of Industry, Innovation and Science under the auspices of the AUSMURI program. S. Primig is supported by the Australian Research Council's DECRA (DE180100440) and the UNSW Scientia Fellowship schemes. The contributions of S.S. Babu were funded by the Department of the Navy, Office of Naval Research under ONR award number N00014-18-1-2794. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Office of Naval Research. The research at Oak-Ridge National Laboratory was sponsored by the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office under contract DE-AC05-00OR22725 with UT-Battelle, LLC. Access to the Oak Ridge National Laboratory's (ORNL) additive manufacturing equipment at ORNL's Manufacturing Demonstration Facility (MDF) was facilitated by US Department of Energy's Strategic Partnership Projects (SPP) mechanism. More information can be found at https://science.energy.gov/lp/strategic-partnership-projects. The authors acknowledge Drs. Vijay Bhatia, Takanori Sato, Hongwei Liu, Magnus Garbrecht, Ranming Niu, Andy H. Wang, and Ms. Ashalatha I.K. Pillai, at the University of Sydney for their technical support. Mr. Edward Whitelock’s (UNSW Sydney) preparation of overview optical micrographs (Fig. 5) is acknowledged. The authors further acknowledge the facilities, and the scientific and technical assistance of the Microscopy Australia node at the University of Sydney (Sydney Microscopy & Microanalysis). This research was sponsored by the Department of Industry, Innovation and Science under the auspices of the AUSMURI program. S. Primig is supported by the Australian Research Council’s DECRA ( DE180100440 ) and the UNSW Scientia Fellowship schemes. The contributions of S.S. Babu were funded by the Department of the Navy, Office of Naval Research under ONR award number N00014-18-1-2794 . Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Office of Naval Research. The research at Oak-Ridge National Laboratory was sponsored by the US Department of Energy , Office of Energy Efficiency and Renewable Energy , Advanced Manufacturing Office under contract DE-AC05-00OR22725 with UT-Battelle, LLC. Access to the Oak Ridge National Laboratory’s (ORNL) additive manufacturing equipment at ORNL’s Manufacturing Demonstration Facility (MDF) was facilitated by US Department of Energy’s Strategic Partnership Projects (SPP) mechanism. More information can be found at https://science.energy.gov/lp/strategic-partnership-projects .
| Funders | Funder number |
|---|---|
| Office of Naval Research | N00014-18-1-2794 |
| U.S. Department of Energy | |
| Advanced Manufacturing Office | DE-AC05-00OR22725 |
| Office of Energy Efficiency and Renewable Energy | |
| Oak Ridge National Laboratory | |
| U.S. Navy | |
| Australian Research Council | DE180100440 |
| University of New South Wales | |
| University of Sydney | |
| Department of Industry, Innovation and Science, Australian Government |
Keywords
- Additive manufacturing
- Hardness
- Microstructure
- Superalloy
- Young's modulus
