High temperature thin film thermocouples on different ceramic substrates

This paper was directed at the effect of ceramic substrate on NiCr/NiSi film thermocouples fabricated on two ceramics substrate. One was on smooth Al2O3 substrate. The other was on silicon carbide ceramic reinforced by carbon fiber (CFCC-SiC). Since the CFCC-SiC has rough surface, the stress between the layer was greater and the thin film was easier to crack. With experiments the measure temperature of the thin film thermocouples on both of them could reach 700°C. Calibrate test data showed that the high-temperature stability of the thin film thermocouple on smooth Al2O3 substrate was much better than the other.