| About this Abstract |
| Meeting |
2023 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2023)
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| Symposium
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2023 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2023)
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| Presentation Title |
Acoustic Mechanisms of Laser Powder Bed Fusion through an Analogous Whistle Model |
| Author(s) |
Yuchen Sun, Aiden Martin, Sanam Gorgannejad, Jenny Wang, Maria Strantza, Nicholas Calta |
| On-Site Speaker (Planned) |
Yuchen Sun |
| Abstract Scope |
In laser powder bed fusion (LPBF), various non-destructive in situ diagnostic techniques are being developed including pyrometry, plasma spectroscopy, and acoustic monitoring, where acoustic monitoring represents an inexpensive, low spatial footprint, and computationally lightweight approach. Recent works have correlated acoustic signals from the printing process with print parameters and overall print quality. This work furthers the correlative understanding of acoustic monitoring and introduces a mechanistic understanding of acoustic generation in LPBF. We first present time-resolved frequency-domain acoustic data of Ti64 to demonstrate its correlation with laser energy density. We then perform non-dimensionalized analyses using Strouhal’s number and analogize the LPBF vapor depression to hole tone systems—exemplified by steam kettle whistles. This comparison reveals two mechanisms of acoustic generation: Helmholtz resonance at lower laser powers, duct resonance and vortex shedding at higher laser powers. This mechanistic understanding of vapor depressions further demonstrates the diagnostic capacity of acoustic monitoring in LPBF.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. |
| Proceedings Inclusion? |
Definite: Post-meeting proceedings |