LAUSR

Previously triboplasma was discovered in the rear gap of the sliding contact in dry sliding in the ambient air. The mechanism of the triboplasma generation has been decided to be caused by discharge of the ambient air through the electron avalanche process due to the intense electric field caused by tribocharge. However, the temperature of the triboplasma has been remained unknown. In this report, the temperature of the triboplasma was successfully measured in the first time using a highly accurate microscopic infrared camera for the triboplasma generated in the gap of the sliding contact while sliding a diamond pin on a sapphire disk in dry sliding under the normal forces of FN = 1 and 2 N at the disk rotational velocities of ω = 10–155 rpm in the ambient air. It was found that the temperature rise of the triboplasma above the ambient one is 0.69 °C at the highest. It demonstrates that the triboplasma is the non-equilibrium low-temperature plasma. The temperature rise of the triboplasma was independent of the repeated sliding and further of the sliding velocity. The temperature rise distribution depends on the tribocharge distribution on the wear track surface and changes periodically with the rotation of the disk specimen. This is because the tribocharge-induced surface potential distribution is nearly unchanged with the repeated sliding.