Friction Property of MoS2 Coatings Deposited on the Chemical-Etched Surface of Al–Si Alloy Cylinder Liner

Abstract

To enhance the friction property of Al–Si alloy cylinder liner in running-in period, MoS2 coatings were electrodeposited on the chemical-etched surface of cylinder liner. The friction coefficient decreased by 15% comparing with the original honed surface, indicating the better friction property. This is because the synergistic action between solid lubricant and etched surface. MoS2 coatings prevent the direct contact between silicon particles and piston ring during friction. At top dead center, the oil film was thinnest and even was broken during the reciprocate friction. When oil film was invalidated, MoS2 coatings undertook lubrication. Then, MoS2 coatings were depleted, and advantage of etched surface became apparent.