| Abstract Scope |
The entire metal additive manufacturing process – from melting to solidification – is driven by the absorbed laser energy. Therefore, it is a quantity of great importance for multiscale, multiphysics model validation, but also one that is notoriously difficult to measure. At NIST-Boulder, we have implemented a light-scattering, energy balance approach based on integrating sphere radiometry. This has achieved nanosecond resolution; an expanded uncertainty of 1.3 %; and has been implemented on bare plate, metal powder, and during line scans. As this project aims to provide meaningful and complete data for model validation, we have combined absorption measurements with other quantitative real-time assessments of process dynamics. This is exemplified by a recent collaboration with Argonne National Laboratory where simultaneous absorption and high-speed synchrotron x-ray imaging measurements allowed specific melt pool dynamics to be correlated with their quantifiable effect on energy absorption. These efforts, and others, will be presented and discussed. |