Additive Manufacturing provides the opportunity to fabricate components of nearly limitless complexity compared to that of traditional manufacturing techniques. However, thermal gyrations imparted into the material from the passing of the heat source cause challenges in fabricating complex structures with the proper process parameters. While the thermal history of the material can be simulated, validating the simulations requires access to thermal data generated through in-situ process monitoring. While generation of in-situ thermal data seems trivial, acquiring and developing reliable calibrations for metallic materials is difficult due to the physical state of the material transitioning from powder to liquid to a solid. To be discussed is the methodology taken to integrate IR in-situ process monitoring within the electron beam melting process and the approach developed to accurately correlate a materials emissivity to temperature during the build process. Further the wealth of information contained within the thermal data will be discussed in the context of understanding of microstructural evolutions within the material during the build process, identification of material defects, and ability to determining the similarity/repeatability of builds fabricated with identical processing parameters as based only on the thermal signature of the build.
High performance mid-wave infrared (IR) cameras are used for in-situ electron beam melt process monitoring and temperature measurements. Since standard factory calibrations are insufficient due to very low transmissions of the leaded glass window required for X-ray absorption, two techniques for temperature calibrations are compared. In-situ measurement of emittance will also be discussed. Ultimately, these imaging systems have the potential for routine use for online quality assurance and feedback control.