COATING THICKNESS AND SURFACE-ROUGHNESS OF TIN-COATED HIGH-SPEED STEEL IN RELATION TO COATING FUNCTIONALITY

Surface roughness of a tool steel is an important parameter in industry. Low roughnesses are needed for a better surface finish of the work piece and are requested by jobcoaters to diminish adhesion problems. A lower surface roughness however requires a longer and more elaborate finishing process which will result in substantial additional costs. The topic of this communication is whether a high coating thickness/high surface roughness system has comparable functional properties to a low coating thickness/low substrate roughness system. For this purpose a number of pin-on-disk tests were performed using two different coating thicknesses and three different surface finishes. Part of this work has already been published [B. Malliet et al., Wear, 142 (1991) 151].