A software-based relocation technique for surface asperity profiles and its application to calculate volume changes in running-in wear

Evaluation of truncated surface asperities is critically important in many industrial applications. Any discussion of truncation processes such as wea r mechanisms and plateau honing requires a comparison of the original profi le with the truncated one. In order to compare profiles, it is necessary to accurately relocate the truncated profile with respect to the original one , However, there is a limitation to relocation using hardware. To achieve a ccurate relocation, the authors propose a software-based relocation techniq ue. In this paper, we present newly two software-based relocation technique s that examine the correspondence between untruncated areas in the truncate d profile and the same untruncated areas in the original profile. In the fi rst technique, the correspondence is measured by a collation index that is determined for the two profiles and calculated in an optimization method. I n the second technique, the height probability distributions of two profile s are calculated and the profiles are then relocated in order to obtain the minimum degree of difference. Furthermore, the applicability of these tech niques is discussed using simulation data and actual measurement data. Thes e techniques are effective in the range that the truncated surface height i s higher than -1.28 sigma(0) (sigma(0) is the standard deviation of untrunc ated original surface height) from experiment, and are useful for measuring very little wear volume changes in contrast with measuring mass changes. ( C) 2000 Elsevier Science S.A. All rights reserved.