About this Abstract |
Meeting |
2021 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2021)
|
Symposium
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Process Development
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Presentation Title |
A Novel Non-destructive Testing Method for Powder Bed Fusion Processes in Laser-based Additive Manufacturing |
Author(s) |
Nicholas S Tomasello, Arad Azizi, Fatemeh Hejripour, Scott N Schiffres |
On-Site Speaker (Planned) |
Nicholas S Tomasello |
Abstract Scope |
A novel technique to measure thermal properties during selective laser melting that modulates the energy source periodically and measures the periodic temperature response to detect defects will be presented. This technique has the benefit of providing thermal conductivity information that can be related to microstructure. The measurement heating frequency can limit the thermal interrogation depth, and so is relatively insensitive to geometry compared to conventional thermography. To demonstrate this work, we built a benchtop printer that uses a blue laser as a melting and thermal interrogation source. The temperature oscillations are measured by a photodiode connected to a lock-in amplifier. By altering the frequency range, different depths into the part can be assessed, and microstructure can be determined. Applications to powder properties, melt pool, and post-printed sensing will also be discussed. |
Proceedings Inclusion? |
Definite: Post-meeting proceedings |