Sensor integration and active damping
Digitalization is evolving in all kinds of fields and industries. The first step in order to make use of data and digitalization is the integration of sensors. With powder bed fusion for metals (PBF-LB/M) the manufacturing of smart and digitalized parts is possible due to the exploitation of the layerwise manufacturing technique. During the build-up of the physical 3-dimensional part every layer can be accessed via a process interruption to place sensors into the metal part.
Fig. 1: H2 Valve with Sensor Integration
We conduct research on the integration of sensors during but also after the PBF-LB/M process. During integration of sensors in additive manufactured parts, there arise several challenges, which need to be addressed in order to guarantee the integrity of the integrated sensor. Excessive heat accumulation, high peak temperatures near the surface, and powder contamination are the most urgent challenges. With the design of customized cavities and encapsulation several sensors where successfully integrated. Temperature, Hall, eddy current and fibre bragg sensors where integrated in demonstrator and industrial parts. A combination of temperature and Hall sensor was integrated into a hydrogen valve from NovaSwiss to enable condition monitoring of the valves used for hydrogen fuel stations. Besides, the initial valve space and weight could be reduced drastically with design optimization and complex flow channels with are not possible to manufacture in conventional ways.
Fig. 2 Camera bracket with Piezo
With a novel developed integration technique, we also achieved to integrate piezoelectric stacks into an aerospace camera bracket, which enables the damping of structural eigenfrequencies. The pre-stressing and structural bonding of the stack was realized with additively manufactured NiTi and usage of shape recovery to pre-stress the stack up to 600 N, which is in the specification of the supplier. Additionally, an electric pre-stress circuit enables the measurement of pre-stress.