Measurement of temperature at sliding polymer surface by grindable thermocouples

• Grindable thermocouple involved in friction indicates an overestimated temperature.
• Lower bound of thermocouple signal is sliding surface background temperature.
• Determination of unsteady temperature requires multiple tests under same conditions.

This paper is devoted to experimental study of capabilities and limitations of grindable thermocouples as applied to polymer materials sliding on metal. Chromel–alumel and chromel–copel grindable thermocouples have been developed and tested for wide ranges of contact pressure and sliding velocity. The background temperature of the sliding surface can be determined as the lower envelope of the signal from the grindable thermocouple. Steady and unsteady regimes of sliding have been investigated. For steady sliding, the accuracy of the temperature determination increases with measurement duration. In the case of unsteady sliding, accurate temperature determination requires multiple tests under the same conditions. The thickness of the thermocouple junction has been analyzed for correct comparison of experimental and calculated temperatures.