FOUNDATIONS OF TOPOLOGICAL CHARACTERIZATION OF SURFACE TEXTURE

More than a hundred years ago Maxwell proposed dividing a landscape in to regions consisting of hills or alternatively consisting of dales. A hill is a set of points from which maximum uphill paths lead to one p articular peak, and a dale is the set of points from which maximum dow nhill paths lead to one particular pit. Starting with Maxwell's ideas this paper sets out to develop the foundations of topological characte rization of surface texture. This leads to a system of surface texture characterization which is complementary to published areal parameters based on the mean line system. In a similar manner that R&W system is complementary to the mean line system for profiles (the dale is the a real equivalent of a motif on a profile). An important example of a tr ue areal characterization contained within this system is the connecta bility of surface valleys. This is important for applications such as lubrication and paintability of a surface. It is also important for ch aracterizing extruded aluminium that has been anodized. The anodizing has cracks (connected valleys) and isolated pits, both of which requir e characterizing separately for production control. (C) 1998 Elsevier Science Ltd.