Integration of Strain Gauges in Components Manufactured by Laser-Based Powder Bed Fusion

The integration of sensors within product components manufactured by additive manufacturing (AM) techniques promises auspicious new possibilities for real time monitoring. Until now, mechanical force monitoring such as compression and strain has been carried out using strain gauges (SG) fixed to the surface of the component by glued or weld-on bonding. This conventional approach has crucial disadvantages: an SG mounted on the component surface does not provide any information about the forces inside the component and is exposed to the surrounding environmental influences.

Due to the layered build-up of AM-parts sensors can be integrated within the part and therefore these drawbacks be overcome. But the usually used adhesive bonding presents challenges for metalworking AM-Techniques regarding the high process temperatures and the curing times of the used glues.

Therefore, this study describes a weld-on method for SG integration where the firm fusion for force transmission is created by applying weld seams between the SG and the AM-component. Since the welding is performed during the metalworking laser-based powder bed fusion process (PBF-LB/M) no additional fixing of the component, e.g. glue, is necessary. After presentation of an SG integration process, an analysis is performed to determine how the load of a test body corresponds to the data of the integrated SG. The results show that the possibility of integrating SGs during the PBF-LB/M process helps in overcoming the disadvantages of conventional sensor mounting concepts. A smooth SG integration process can be ensured allowing future research to focus on automating this process.