In laser powder bed fusion, melt pools that run too cold cause lack of fusion, while melt pools that run too hot cause evaporation and porosity. The NDML is developing infrared thermography methods that measure melt-track temperatures during the build with quantified uncertainty. An infrared camera mounted at the optical window of an EOSINT M280 records each layer, and Kalman filtering combined with measured powder emissivity converts the images into temperature estimates with an uncertainty of about ±7%. These measurements sort each region of the build into quality classes and can be used to generate control signals that adjust the laser power. The approach has been demonstrated on 316L stainless steel and Inconel 718, including studies of how powder particle size affects melt pool stability and porosity.
The figure above shows the infrared camera installed on the EOSINT M280.