Surface topography and tribology of cast iron in boundary lubrication

This work aims to study and understand the influence of the surface topography oil wear of grey cast iron used for heavy duty diesel engine cylinder liners. A micro-alloyed grey cast iron was tested with different surface topographies. These were polished surfaces, honed Surfaces (with two different honing parameters) and three model surfaces with well defined grooves oil a polished specimen. Reciprocating friction tests using a steel ball rubbing against a flat or a cylindrical sample (extracted from a cylinder liner) were carried out oil a Cameron Plint test rig. A commercial synthetic oil for diesel engine was used as the lubricant. The friction coefficient and the electrical contact resistance were Measured during the tests. The Wear Volume of the cylinder liner part was also measured at the end of the test. The influence of the surface topography on the tribochemical film formation and on the wear behaviour of cast iron was established. Surfaces exhibiting lots of Surface asperities had the highest mainly due to delayed formation of protective tribochemical film. In our test conditions, the wear, spacing between the grooves oil model specimens had no influence on the wear behaviour of the cast iron specimens. (c) 2009 Elsevier Ltd. All rights reserved.