FRACTAL PARAMETERS AND COMPUTER IMAGE-ANALYSIS APPLIED TO WEAR PARTICLES ISOLATED BY FERROGRAPHY

Morphological analysis of wear particles is a very effective and versatile means of lubricant analysis for machine condition monitoring and fault diagnosis. The qualitative methods currently in use for the study of wear particle morphology are time consuming and require substantial expertise in this area. If numerical parameters could be used to characterize wear particle morphology, the analysis of such particles would become much simpler and not require specialized expertise. In this paper fractal descriptors are applied to wear particle boundaries. The morphology of a wear particle depends greatly on its surface characteristics. These characteristics are not always effectively represented by a fractal dimension derived from the boundary profile. Here a fractal descriptor characterizing the surface characteristics of particles is introduced. When used in conjunction with established fractal methods, more precise particle characterization is obtained.