Wear resistance mechanism of engine piston skirt coating under cold start condition

Abstract At the beginning of cold start, the lubricating oil temperature is low, the kinematic viscosity is high, the splash lubrication effect is poor, and the good lubricating oil film cannot be formed, therefore, the friction and wear between piston and cylinder is serious. In this paper, the wear mechanism of aluminum alloy piston skirt coating was studied in the cold start stage with severe wear degree: the dynamic simulation and cold start test analysis were carried out for the skirt with or without coating, and the wear morphology, knife pattern structure and friction force were compared, so as to determine the friction reduction energy efficiency of the coating in the cold start stage.