Laser strengthening of air-cooled diesel engine phosphorus cast iron cylinder liner and its friction & wear properties

This paper presents the research on laser hardening of phosphorus cast iron cylinder liner for air-cooled diesel engine. The microstructure, microhardness, friction and wear properties of the strengthened layers were investigated. The research results indicate that laser surface melting treatment results in the disappearance of strengthening phase phosphide eutectic, which deteriorates the property of the phosphorus cast iron. Laser transformation hardening can improve the property of phosphide eutectic. In some processing conditions, the phosphide eutectics remelt and crystallize into a fine structure, and some binary phosphide eutectics convert into ternary. Tribological tests indicate that the reservation of the original phosphide eutectic and the morphology of the phosphide eutectic after laser hardening have significant influences on the friction & wear properties of phosphorus cast iron cylinder liner.