Kinematic influences on the formation of the footprint during local polishing of steel

The local form correction of mould inserts for the replication of ultra- precision glass optics can be achieved by means of the zonal corrective polishing. The understanding of the formation of the characteristic footprint of the polishing tool is necessary for the deterministic and straight forward correction of the optical component. With the 'Adaptive Polishing Head' designed at the Fraunhofer IPT/ WZL individually user defined kinematics can be superimposed to a locally working polishing tool ensuring a close control of the polishing pressure. This unit has been used to investigate the influences on the formation of the local footprint formation during polishing of steel. Within the paper the tribomechanical correlations within the gap between the polishing cloth and the work-piece surface are discussed. As models for the understanding of the material removal the theorem of Preston and the coherences of Stribeck are used. In addition, the finishing of a free- form optic is presented. The research project is funded by the Deutsche Forschungsgemeinschaft DFG within the project SFB TR4.