Wear 271 (2011) 548–552 Contents lists available at ScienceDirect Wear journal homepage: www.elsevier.com/locate/wear Characterisation of worn cylinder liner surfaces by segmentation of honing and wear scratches Z. Dimkovski a,∗ , C. Anderberg a,b , Robert Ohlsson c , B.-G. Rosén a a Halmstad University, School of Business and Engineering, P.O. Box 823, SE-301 18 Halmstad, Sweden b Volvo Car Corporation, Göteborg, Sweden c Volvo Powertrain Corp., Volvo Group, Göteborg, Sweden article info Article history: Received 22 January 2010 Received in revised form 16 April 2010 Accepted 22 April 2010 Available online 1 May 2010 Keywords: Cylinder liners Engine tests Honing grooves Axial wear scratches abstract The presence of the honing scratches/grooves in cylinder liner surfaces is intended and desired as they improve the lubrication and retain the debris reducing the piston assembly/liner friction and conse- quently improve the fuel economy and longevity of the internal combustion (IC) engines. Axial scratches caused by the abrasive wear between the tribological partners and/or entrained wear particles are unde- sired since they are correlated with increased oil consumption and noxious emissions of the IC engines. Due to the imperfection of the manufacturing process, the honing grooves, especially the deep ones, are smeared and interrupted by folds. A portion of the folds would eventually detach during the running process and act as abrasive particles increasing the wear in the cylinder. To closely examine the influ- ence of all these features on the liner’s function, it emerges a need to objectively quantify the axial wear scratches, plateau honing grooves, deep honing grooves and their interrupts. The existing techniques fail to segment a groove containing interrupts as they usually appear as summits at several locations in the course of the groove. Combining the profile and image analyses, the deep grooves and their interrupts were successfully identified and quantified in earlier works of the authors. In this paper those algorithms are extended, so that the deep honing grooves, plateau honing grooves and axial scratches crossing dif- ferent depth levels are sequentially segmented in three levels/steps in an immersing way. A number of parameters derived from this method were utilised to compare 3D interference measurements from the top dead centre, middle and bottom region of a liner run in a truck engine test whereas the three regions represent different wear regimes due to the different running conditions. The results show that: (i) the axial scratches are densest in the top dead centre and about the same size as the plateau grooves in all three regions, while in the bottom region there are only few scratches; (ii) the presence of plateau grooves in the top region clearly decreases, (iii) the deep groove interrupt and coverage are lowest in the top region, and (iv) the groove height and distance between grooves spread mostly. © 2010 Elsevier B.V. All rights reserved. 1. Introduction The friction between the piston assembly and cylinder liner sur- face accounts for about a half of the total frictional losses in the IC engines [1]. Additionally, the noxious emissions, like HC–, CO–, CO 2 and NOx are controlled by the cylinder liner topography [2]. As a consequence, the optimisation of liner topography is of manufac- turing, consuming and environmental interests. Manufacturers of cylinder liners have been relying on a surface finish manufactured in multi-stage honing process which results in a cross hatched plateau-like surface topography. The deep honing grooves are obtained by using courser abrasive grains and apply- ing higher contact pressures, while the plateaus are formed by finer ∗ Corresponding author. Tel.: +46 35167752; fax: +46 35167564. E-mail address: zlate.dimkovski@hh.se (Z. Dimkovski). grains and lower contact pressures in the final plateau honing stage. Lately, the diamond abrasives have been introduced to increase the consistency and productivity, but as a disadvantage the for- mation of torn and folded metal increased [3]. These folds, mainly interrupting the deep grooves (also found on plateaus, in a smaller amount), represent a potential danger in the service of the liner sur- face. A large amount of the folds will be detached/removed from the top dead centre (TDC) region, since it operates in boundary lubri- cation regime under high cylinder gas pressures, and the increased amount of loose particles will create axial scratches increasing the liner’s wear [4]. The folds were merely removed from the middle liner region, where the piston assembly and liner operate in hydro- dynamic regime (thereby experiencing mild wear), and the least worn bottom region where only the piston skirt runs. Even though the folds are largely removed from the TDC region, it is a small part of the overall liner surface and that is one of the reasons why the liners in the present engines operate at an acceptable level. Never- 0043-1648/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.wear.2010.04.024