98 Int. J. Surface Science and Engineering, Vol. 2, Nos. 1/2, 2008 Copyright © 2008 Inderscience Enterprises Ltd. Influence of roughness parameters of harder surface on coefficient of friction and transfer layer formation Pradeep L. Menezes and Kishore Department of Materials Engineering, Indian Institute of Science, Bangalore 560 012, India Satish V. Kailas* Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560 012, India Fax: +91-80-23600648 E-mail: satvk@mecheng.iisc.ernet.in *Corresponding author Abstract: Various surface textures, characterised in terms of roughness parameters using an optical profilometer, were produced on the steel plates. Sliding experiments were conducted on the prepared hard steel plate using a soft Al-Mg alloy pin under both dry and lubricated conditions. The contact surfaces were examined using SEM to study the transfer layer formation on the plate surface and damage on the pin surface. Results showed that among the surface roughness parameters, the coefficient of friction and transfer layer formation are strongly controlled by a roughness parameter, namely mean slope of the profile, a, regardless of the surface textures. Keywords: friction; surface texture; transfer layer; roughness parameters; sliding tests. Reference to this paper should be made as follows: Menezes, P.L., Kishore and Kailas, S.V. (2008) ‘Influence of roughness parameters of harder surface on coefficient of friction and transfer layer formation’, Int. J. Surface Science and Engineering, Vol. 2, Nos. 1/2, pp.98–119. Biographical notes: Pradeep L. Menezes received his M.Tech in Materials Engineering from the National Institute of Technology (NIT), Surathkal, India in 1999. He has completed PhD from the Department of Materials Engineering, Indian Institute of Science (IISc), Bangalore, India in 2008. He is currently a research associate at the same Department at IISc. He has authored 18 research articles published in various international journals. His current research interests include friction, transfer layer, metal forming and surface textures. Kishore received his Bachelors Degree in both the Science and Engineering disciplines. Masters in Engineering and Doctorate in the area of Physical Metallurgy followed this. He has authored over 170 papers in the areas of Structure Property Correlations, Tribology and Polymer Composites. His current interests include the study of surface texture in the tribological