Thin-Film Temperature Sensors for Wheel Treads on high-Speed Trains

In response to the challenges posed by significant te mperature variations on the wheel tread surface, limited temperature measurement locations, frequent vibrations of the wheel hub, and the difficulty in measuring contact temperatures during high -speed train operation, a self-renewing, wear-resistant thin-film te mperature sensor has been developed. This sensor utilizes a NiCr/ NiSi thin film as the sensitive material. The dynamic and static ch aracteristics of the thin-film temperature sensor, fabricated via D C pulsed magnetron sputtering, have been calibrated. The results demonstrate that the developed sensor exhibits excellent linearity over the temperature range of 30–420 °C, with a Seebeck coeffici ent of 38.1 µV/°C and a dynamic response time of 225 ns. Simulat ed experiments on the wheel-rail contact conditions reveal that we ar at the temperature-sensing end of the thin-film sensor significa ntly influences its dynam-ic and static characteristics. However, t he findings indicate that wear at the temperature measurement ju nction does not adversely affect the sensor's performance within t he wear range, suggesting that the sensor's temperature measure ment capabilities remain stable despite wear at the sensing interfa ce.