Temperature measurements at the sliding contact using exposed and embedded thermocouples with an inverse heat conduction correction

• Embedded thermocouple underestimates the friction surface temperature. • Exposed thermocouple can underestimate/overestimate the friction surface temperature. • Exposed thermocouple measurements correspond to the temperature evolution at 0.1 mm. • More intensive friction of exposed thermocouple leads to higher indicated temperature. • Exposed and embedded thermocouples allow determining the friction surface temperature. Temperature has a strong influence on tribological performance. This study aims to improve temperature measurements at the friction surface by combining the techniques of exposed and embedded thermocouples with an inverse heat conduction method. The pin-on-disc experiments, which simulate the friction conditions in a car brake, showed that the embedded thermocouple indicates a suppressed and delayed temperature. In contrast, the exposed thermocouple can both overestimate and underestimate the peak temperature, depending on the extent of its involvement in friction with the counter-surface. The mean peak temperature indicated by the exposed thermocouple corresponds to the temperature evolution at a distance of 0.1 mm from the friction surface. By combining the techniques, the temperature at the friction surface can be determined with higher accuracy.