Wear Behaviour and Tool Life of Wire-EDM-ed and Ground Carbide Punches

This paper describes and discusses the wear behaviour and tool life of a cemented carbide punch produced in eight different qualities. Six samples covering a wide variety of EDM surface textures and surface integrities are compared to the performance of two ground punches. All punches have been tested on an industrial press. Burr height measurements on the stamped material, used as an evaluation of tool life, does not indicate significant influences of the production process. A more detailed analysis of the punch surface after 1×106 punch cycles shows the presence of different wear zones. The surface layer influenced by the production process, either EDM or grinding, is completely removed in the zones near the cutting edge.