Cavitation induced starvation for piston-ring/liner tribological conjunction

► Investigation of the mechanism of lubricating film formation in the vicinity of the top dead centre (TDC) and bottom dead centre (BDC) of an internal combustion (IC) engine's piston ring-liner conjunction. ► It was found that cavitation, which is located at the trailing edge of the contact before the reversal, briefly survives after the reversal as a confined bubble at the leading edge. ► This cavity depletes the film and promotes starvation. ► It is concluded that due to the cavitation induced starvation, in the proximity of the dead centres the contact film is significantly thinner and the friction force significantly higher than initially thought.