|About this Abstract
||MS&T23: Materials Science & Technology
||Additive Manufacturing: Equipment, Instrumentation and In-Situ Process Monitoring
||Two-color Melt Pool Thermal Imaging on Powder-blown Laser-DED to Advance Understanding of Melt Pool Thermal-fluid Physics
||Alexander J. Myers, Guadalupe Quirarte, Jack L Beuth, Jonathan A Malen
|On-Site Speaker (Planned)
||Alexander J. Myers
An experimental technique to image melt pool temperature with a commercial color camera for powder-blown laser directed energy deposition (L-DED) was developed. This technique relies on two-color thermography and high dynamic range photography to construct spatially-resolved thermal fields of 316L stainless steel melt pools from solidus to vaporization. By leveraging the principle of two-color thermal imaging, the need for a priori knowledge of melt pool emissivity and the camera’s view factor is negated. The system's ability to accurately measure temperature was validated with a calibrated tungsten filament. Comparing in-situ temperature measurements and ex-situ cross-sectional geometry to multi-physics computational fluid dynamics models provides a means of calibrating uncharacterized parameters, such as the temperature-dependence of surface tension. This state-of-the-art process monitoring tool provides multi-physics CFD model validation, cooling rates in the melt pool tail, and process mapping of critical melt pool behaviors such as the peak temperatures across processing space.