Tribological Investigation of The Effect of Aluminum Alloy in Accordance with Cast Iron Liner on Engine Wear

The tendency to use aluminum alloys to replace conventional gray cast irons (GCI) materials in engine blocks of passenger cars is gaining more and more importance driven by reduction of engine weight to achieve expectation for lowering fuel consumption and CO2 emissions. In this work the tribological effect of new produced aluminum engine cylinder liner is compared with the conventional cast iron the cylinder bore for friction, lubrication and wear-resistance. Their tribological performance was evaluated through a reciprocating tribometer, using steel ball (100 CR6) on an aluminum and cast iron Diesel engine cylinder liners with 5W-40 engine oil to investigate their wear and friction behavior in boundary lubrication regime. There is a great effect of the roughness of machining marks (honing) on the surface of the liner. Although the same honing type was applied on both liner sleeves, aluminum liner presented less wear track, less roughness smoother surface related to cast iron liner. Repeated friction tests presented almost similar coefficient of friction data. Friction and wear comparison is well determined and the rubbed surfaces as well as all additives were analyzed through 2D-3D roughness digital optical microscopy, SEM-EDX analysis.