Dennis Höfflin¹, Christian Sauer¹, Andreas Schiffler¹, Jürgen Hartmann¹^,²

¹ Hochschule für angewandte Wissenschaften Würzburg – Schweinfurt, Schweinfurt

² Bayerisches Zentrum für Angewandte Energieforschung e.V., (ZAE Bayern), Würzburg

Process monitoring in metal powder bed fusion is not only important for the qualification of parts and processes, but for the early detection of anomalies and process faults. Nevertheless, determining temperatures and temperature gradients during the manufacturing process remains a difficult task due to the fast running processes and the small region of interest. In addition, changes in the emissivity of the material during transitions of the aggregate states make it challenging to contactless measure material temperatures in the area of the laser interaction zone.

The contribution shown here presents a process observation approach based on two independently moving scanner units, one for guiding the laser the other for the thermographic camera. With the shown setup it is possible to follow the laser beam at a freely definable distance and thus continuously avoid the for temperature measurement critical laser-material interaction area. Therefore, temperatures and temperature gradients can be determined in areas with known emissivity.

First results of measurements of the aluminium alloy AlSi10Mg using a InfraTec IR 8300 with a resolution of approximately 15 µm per pixel at a framerate of 2000 fps are presented.

Acknowledgement: The research was funded by the Bavarian Ministry of Economic Affairs, Regional Development and Energy‎ funded projects ProDiMe (FKZ 6665e/366/2) and ViPaF (FKZ 41-6562b/25/2-VAL-2103-0006).