Thermally sprayed coatings for protection of integrated sensor systems on tribological loaded surfaces

Piezo-element integration in WC-NiCr and Cr3C2-NiCr thermally sprayed coatings resulted in electric voltage curves, which can provide information about the wear and friction condition in the tribological contact zone. The coatings were produced by high-velocity oxy fuel (HVOF) spraying with a thickness of 350 mu m. The thermal sprayed coatings provided good wear protection of the embedded piezo-elements. The electrical energy outcome was slightly higher for the more wear resistant WC-NiCr coatings under dry sliding with a WC-12Co ball. The Cr3C2-NiCr coatings are known to give a better wear resistance at higher temperatures, but exhibit an inferior behaviour in comparison to WC-NiCr coatings at room temperature. This tendency was observed and is very well mirrored by the shape of electric voltage and the electric signal output at room temperature. Piezo-element integration was carried out after HVOF spraying embedding the 200 mu m thick piezo-elements into cross-sectional slit which was produced by wire erosion.

Automated summary

The integration of piezo-elements in WC-NiCr and Cr3C2-NiCr thermally sprayed coatings produced electric voltage curves that can indicate wear and friction conditions. WC-NiCr coatings showed slightly higher electrical energy outcome under dry sliding, while Cr3C2-NiCr coatings demonstrated better wear resistance at higher temperatures.