Thermal multi-sensor instrumentation for the enhancement of a directed energy deposition process

Abstract

Abstract. Directed energy deposition (DED) is an additive manufacturing process with growing industrial interests. Nonetheless, its industrialization will not be possible until it is fully mature. Such maturity lies in the upstream research to optimize and control it. In DED, process parameters, physical quantities and parts properties are interrelated which makes it a complex process. To have a better understanding of these relations, the experimental approach of instrumentation has been chosen. Multi-sensor method has been implemented for its more extensive possibilities in comparison to single-sensor methods. A bichromatic pyrometer was coupled to an IR camera to measure the temperature distributions in real time. Post-process characterizations of the aspects and geometries of the parts were related to the sensors’ measurements and consequently, to the process parameters. Twelves sets of parameters were tested to conclude that the energy input impacts the size of the melting pool and the temperature distribution. High energies lead to defects such as edge defects and layer thickening but can mitigate surface roughness. Both the pyrometer and camera proved to have a relevance in this study for the enhancement of the DED process.