Effect of Surface Topography on Friction and Wear of Cast Iron for Cylinder Liners

This work aims to study and understand the influence of the surface topography on wear of grey cast iron used for heavy duty Diesel engines cylinder liners. A micro-alloyed grey cast iron is tested with different surface topographies: two honed samples with different honing parameters, a polished sample and three model samples with well defined grooves on a polished specimen. Reciprocating friction tests with the configuration steel ball against a flat or a cylindrical sample, extracted from a cylinder liner, in lubricated contact, are carried out on a Cameron Plint test rig (with commercial synthetic oil for Diesel engines). The friction coefficient and the electrical contact resistance are measured during all tests. The wear volume evolution of the cylinder liner part is determined. The influence of the surface topography on the tribochemical film formation and on the wear behavior of cast iron is identified. The surfaces exhibiting lots of surface asperities have the highest wear, mainly due to a delayed formation of protective tribochemical film. In our conditions, the spacing between the grooves on model specimens has no influence on the wear behavior of the cast iron specimens.