ULTRASONIC ASSISTED TURNING OF HARDENED STEEL WITH MONOCRYSTALLINE DIAMOND

INTRODUCTION The demand for ultra-precise steel parts with optical surface qualities and complex shaped geometries is increasing and could be applied for plastic injection molding or precision glass molding processes. Nowadays optical molds for injection molding are coated with a nickel layer, in order to be able to machine the surface with diamond tools. Directly machined steel parts would decrease manufacturing time, making the coating process step unnecessary. Additionally, the life time of the mold is increased dramatically. Uncoated steel tools have a higher scratch resistance and no risk of delamination. Therefore the potential of directly machining steel with monocrystalline diamond is exceptionally high.