In-Situ Measurement of the Temperature Progression in Metal Components Manufactured by Laser-based Powder Bed Fusion

Laser-based Powder Bed Fusion (LPBF) is one of the most common processes in the field of metal-based additive manufacturing (AM). Using LPBF parts are generated layer-by-layer. This build-up process can be interrupted and resumed, e.g. to insert components, such as sensors into a manufactured cavity of the part. The integration of sensors is of great interest for many industrial applications as it allows industry 4.0 approaches such as predictive maintenance. Using LPBF, sensor-monitored structures can be built that contain fully encapsulated electrical components that are invisible from the outside and inaccessible after the production process. However, process-related high thermal loads that act on an inserted sensor when the cavity is closed limit the integration possibilities so that the function can be impaired or even destroyed. Within the scope of this work, the temperatures that occur in a cavity during the process are experimentally quantified by integrating temperature sensors. Various measures and strategies are introduced to protect inserted components from harmful temperatures and are evaluated based on experiments. This paper presents and analyses local temperature curves in an LPBF part during the build process. Resulting modifications to component designs (solution concepts) and exposure parameters are experimentally validated. The solution concepts are also evaluated through an analysis of the advantages and disadvantages.