Dual Wavelength Pyrometry Imaging of a Melt Pool

: The goal of this experiment was to further investigate the thermal fluid behavior of the melt pool formed in the process of Direct Laser Deposition (DLD) metal additive manufacturing. This was done through the use of dual wavelength pyrometry, as this temperature measurement technique doesn’t require knowledge of the materials emissivity. The pyrometer was configured with 2 FASTCAM MINI AX-200 monochrome cameras and narrow band pass filters with wavelengths of 750nm and 950nm, respectively. This system was calibrated using a black body to determine an experimental fit between gray scale ratio values and surface temperature. This experimental fit was then applied to recordings taken inside a DLD system and a temperature map was determined using an image processing script in MATLAB. The certainty in these results was limited due to the small range of calibration data. Further experiments should be done at higher temperatures to ensure the validity of these results, and improvements to overall image processing and system alignment should be implemented before repeating experiments in the DLD system