Laser-induced texturing of grey cast iron for enhanced tribological performance

Abstract

Surface texturing and its topography significantly affect the tribological performance and lifecycle of automotive components at elevated temperature, fluctuating load and speeds. Engineered surfaces using laser-induced texturing is most promising approach to address these concern by varying texture morphology, orientation and roughness. Therefore, the present study propose fabrication of seven distinct textures namely, chevron, triangles with vertex along sliding length (TAL) and width (TAW), rectangular (RT), square (ST), staggered circle (SCT), and circle (CT) by variation in texture shapes and orientation keeping constant density, pitch and depth on grey cast iron (GCI) for cylinder liner piston ring pair (CLPRs) application. Laser-induced texturing increases the areal roughness and microhardness due to variation in scanning strategy and grain refinement. Lowest COF is observed for moderate load of 80N and sliding velocity of 0.2 m/s. RT shows highest reduction in frictional coefficients (COF) and friction force (FF) of around 26.6% compared to base due to least bulge and stabilized film thickness whereas TAL has lowest. Chevron has highest roughness, bulge height, microhardness, least mass loss and most wear prone surface. Worn morphology indicates textures were intact and wear mechanics related to topographical parameters.