A methodical approach for the integration of foil-type strain gauges in PBF-LB/M components

Powder bed fusion of metals using a laser beam (PBF-LB/M) enables the production of smart components by facilitating the integration of sensors almost anywhere within a part through its layer-by-layer manufacturing process. This allows for sensor placement near critical points of interest while providing protection against environmental influences. This study introduces a novel methodology for integrating bonded linear foil strain gauges within PBF-LB/M components - an approach not previously explored. The objective was to achieve reproducible in-situ monitoring of strain loads in components, with strain gauges integrated flexibly and cost-effectively during the PBF-LB/M process. Key steps included assessing the temperature at the integration position, selecting a suitable adhesive, preparing the bonding surface to optimize adhesion, designing appropriate cavities for sensors and wiring, and establishing guidelines for manual integration of the strain gauge within the PBF-LB/M environment. The feasibility of this integration methodology was successfully validated through strain measurements obtained from tensile tests on a sample with an integrated strain gauge. The measurement signal demonstrated a faithful measurement of strain and exhibited minimal deviations between repeated measurements.