In situ embedding of resistance temperature detectors with the use of laser-foil-printing additive manufacturing

Additive manufacturing (AM) allows sensor embedding with the freedom of geometry flexibility. This research aims to experimentally determine the viability of integrating Platinum resistance temperature detectors into AM 304L stainless steel parts using laser foil printing (LFP) for real-time measurement applications. Using metal foils as a feedstock in LFP provides higher conductivity and faster cooling rate resulting in higher strength compared to powder-bed AM. However, one of the common challenges during the laser aided metal AM processes is that the heat accumulation can damage the embedded sensor. This study uses spot pattern welding processing strategy to mitigate these process-related risks by minimizing the melt pool volume during the layered fabrication process. High-temperature resistant ceramic adhesives are employed to fill the gap, and to create a conductive interface between the feedstock and the sensor. After curing the ceramic adhesives, in situ temperature measurement data are collected to investigate the success of the sensor embedding process. This work demonstrates the feasibility for LFP smart manufacturing, offering the potential for component embedding and an advanced real-time monitoring system.