Wear resistance of copper EDM tool electrode electroformed from copper sulfate baths and pyrophosphate baths

Electroforming copper from the copper sulfate baths or the pyrophosphate baths is one of commonly used methods for manufacturing electro-discharge machining (EDM) tool electrode, in particular for the fabrication of micro- and meso-scale tool electrodes with complex cross-section, but few literature on the electrode-wear performance of electroformed copper electrode has been available until today. To better select copper tool electrode materials, the wear resistance of the macroscopic and tiny copper tool electrodes deposited from the copper sulfate baths and the pyrophosphate baths were investigated comparatively with the same micro-EDM parameters. The optimal electrodeposition parameters in which the deposited copper had the lowest electrode-wear ratio were first obtained from the two baths, respectively. And then, the wear resistance of the micro-featured copper tool electrode electroformed using the optimal deposition conditions from the two baths were evaluated comparatively. Experimental investigations showed that, both at the macro-scale level and at the micro-scale level, the copper tool electrode electroformed from the pyrophosphate baths (the smallest electrode-wear ratio was 10% for the macro-electrode and 12.8% for the micro-electrode) exhibited better wear resistance than that deposited from the copper sulfate baths (the smallest electrode-wear ratio was 11.95% for the macro-electrode and 17.3% for the micro-electrode).