Tribological studies of lubricated textured point contacts using MoS2 and PTFE nano oils under the reciprocating motion

Abstract

Friction, wear, and film formation behaviors at the lubricated textured point contacts have been investigated experimentally by employing MoS2 (Molybdenum disulfide) and PTFE (polytetrafluoroethylene) nano oils at high contact loads (Hertzian pressures, PH = 1.5, 2.5, and 3.5 GPa) and low sliding linear reciprocating speeds ( U s = 0.1 and 0.4 m/s). Two types of contacts formed between “grounded conventional flat plate versus lapped ball” and “grounded textured flat plate versus lapped ball” were used in the experimental investigations. The friction force, wear of balls, contact potential (an indication of oil film formation ability), and vibrations were measured and analyzed herein. Overall better tribological performances have been achieved with PTFE nano oil as compared to MoS2 nano oil. However, relatively more vibration reductions have been found with MoS2 nano oil. The EDS and XPS analysis along images of worn surfaces have been presented and analyzed for wear quantification and realization of the associated mechanisms.