Laser Processing of Coarse Grain Polycrystalline Diamond (PCD) Cutting Tool Inserts using Picosecond Laser Pulses

Manufacturing of cutting edges in PCD cutting tool inserts (CTI) using picosecond pulsewidth laser sources is presented. Cutting edge radii of redge = 5 to 6 μm are achieved. Validation experiments are carried out on a turning lathe using lasered and ground CTI on machining carbon fibre reinforced plastics (CFRP) which is mainly used for aircraft structures. Experiments are done on fine and coarse grain PCD structures (average grain sizes are 2-4 μm and 25 μm resepectively) which are not economical in the latter case if manufactured conventionally, e.g. using grinding processes. Wear resistance, tool lifetime and process forces can be improved if laser processed coarse grain cutting tools are employed.