Machining of Micro Dimples for Friction Reduction in Cylinder Liners

In combustion engines a large percentage of mechanical losses result from friction, for example within the cylinder liner. In order to reduce the friction between cylinder liner and piston, micro dimples in the surface decrease the internal friction of combustion engines. These dimples hold back lubricant from being pressed out of the tribological contact zone which enhances the friction behaviour. Competing processes such as laser material removal allow micro dimples to be generated at high productivity. Therefore the process time of machining micro dimples needs to be reduced in order to maintain low production costs. For this purpose a rotating single-toothed tool is used in an axially parallel turn-milling process. The aim of this paper is to show the investigation of productive machining and the effect of the micro dimples in heavy duty cylinder liners. The cutting behaviour is investigated by analyzing micro dimples cut at high speed concerning their burr formation and geometrical deviations.