The effect of wear on surface texture

Abstract

Wear is an important phenomenon to consider in the design and application of engineering surfaces. Surface metrologists generally study the effects of wear by means of the average height sensitive roughness parameters which consider surface profile data as a whole. These parameters do not take account of the separate contributions to the overall surface texture of the remnant of the original unworn surface which remains after wear occurs and the new surface component created by the wear process. For the limited depths of wear which are allowed in most engineering applications before one decides that “failure” has occurred, the “worn” surface retains some of the features of the original surface in addition to having new features which were generated by the wear process. The former are found in the bottom of the original surface profile and remain at the bottom of the new surface profile, while the latter are confined to the top of the new profile. The surface resulting from an abrasive wear process thus exhibits a two-stratum transitional topography and the surface texture contributions of the individual strata are readily analyzed by the use of probit scaled plots of the cumulative height distribution of the surface profile. These ideas are illustrated by analysis of a simple deterministic profile model and a probabilistic model. They have been verified by the results of an experiment which simulated an abrasive wear process. The method used for the analysis of the wear process is shown to be applicable to all types of two-stratum transitional topographies.