2026/01/01 by Jihoon Jeong, Dong Hee Kang
Engineering · #Additive Manufacturing Materials and Processes #Thermography and Photoacoustic Techniques #Calibration and Measurement Techniques
paper · doi:10.1016/j.cirp.2026.04.018
Additive manufacturing (AM) of copper is challenging due to its high thermal conductivity, low absorptivity under infrared lasers, and oxidation sensitivity. This study newly presents an integrated in-situ melt pool monitoring framework for blue laser powder-blown directed energy deposition (LP-DED) using multispectral imaging and photodiode sensing. Multispectral thermometry (MST) provides spatially resolved temperature and emissivity maps, while photodiode-based Planck thermometry (PDPT) enables high-speed radiance tracking. The measured thermal responses are highly sensitive to laser power and shielding conditions. The combined MST-PDPT analysis reveals how variations in emissivity affect temperature interpretation. The proposed multi-sensor approach establishes a foundation for reliable real-time thermal assessment and future closed-loop control of blue laser copper deposition.