Abstract
Scalmalloy® is a novel alloy designed to work with the unique processing inherent in additive manufacturing (AM). This alloy is post-processed using a single artificial aging treatment rather than a multistep heat treatment, as often noted in traditional manufacturing processes. Much of the literature details the impact of direct aging treatments around the temperature and time recommended by the manufacturer, 325 °C for 4 h; however, few studies have explored the impact of delayed artificial aging on the resulting mechanical and microstructural behavior. This study explored this missing link and determined the impact that the time between the fabrication of the component and artificial aging has on the final properties. For this study, directed energy deposition (DED) was utilized to fabricate Scalmalloy® components. Post-processing via artificial aging was performed after fabrication to yield samples naturally aged for 0, 2, 4, 6, 8, 10, 12, and 14 days. Samples were subsequently aged at 325 °C for 4 h. Tensile testing determined that natural aging negatively impacts tensile strengths. After 6 days of delayed artificial aging (6 NA), the yield strength (YS) and tensile strength (TS) relative to day 0 (0 NA) case were diminished by 10% and 8.6%, respectively. After 12 days (12 NA), even greater property decreases were noted, with a 23% decrease in YS and an 18% decrease in TS. Microstructural characterization was performed and an increase in precipitate size and decrease in precipitate number coupled with increased grain sizes were theorized to be linked to the decrease in tensile properties. The negative impact of delayed artificial aging after AM fabrication for Scalmalloy® highlights the importance of fast transitions from deposition to heat treatment.
Recommended Citation
R. Boillat-Newport et al., "Impact of Delayed Artificial Aging on Tensile Properties and Microstructural Evolution of Directed Energy Deposited Scalmalloy®," Applied Sciences (Switzerland), vol. 15, no. 7, article no. 3674, MDPI, Apr 2025.
The definitive version is available at https://doi.org/10.3390/app15073674
Department(s)
Mechanical and Aerospace Engineering
Publication Status
Open Access
Keywords and Phrases
additive manufacturing; aluminum; delayed artificial aging; directed energy deposition; heat treatment; laser-based processing; natural aging; Scalmalloy ®
International Standard Serial Number (ISSN)
2076-3417
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2025 The Authors, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
01 Apr 2025
