THE EFFECT OF SURFACE-ROUGHNESS ON DYNAMIC FRICTION BETWEEN NEOLITE AND QUARRY TILE

It is known that surface roughness affects friction. However, it is no t clear which surface characteristics are better correlated with frict ion. An extensive search for a relationship between surface roughness parameters and friction was completed in this study. Surface roughness on unglazed quarry tiles was systematically altered by sand blasting. A commercially available pin-on-disk tester was used to measure dynam ic friction under broad testing conditions at the interface. A commerc ially available profilometer was used to measure the surface roughness of the tiles. The results indicated that, among the surface parameter s evaluated in this study, R-pm and Delta(a) had the highest correlati on with friction. R-pm is the average of the maximum height above the mean line in each cut-off length and represents the averaged void volu me among asperities on the surface, Delta(a) is the arithmetical avera ge of surface slope and is related to the rate of asperity deformation during a sliding contact. The averaged sur face parameters generated from eight surface measurements from an area of interest were sufficie nt to give a fairly good indication of surface friction. (C) 1998 Else vier Science Ltd. All rights reserved.