Patent ID: 7394040

Claim:
An electromachining apparatus for roughing and finishing a workpiece, the apparatus comprising: an electrode spindle system adapted for receiving removable first and second electrodes spaced apart from a workpiece; a DC power source in electrical communication with the electrode spindle system; an electrolyte fluid source in fluid communication with the first electrode, wherein the electrolyte comprises solely an aqueous solution having an electro-conductivity solely between about 20 micro Siemens/cm and 100 milli Siemens/cm; and a dielectric fluid source in fluid communication with the second electrode; wherein the fluid communication is controlled by a valve, wherein the electromachining apparatus is configured to first provide solely an electroerosion roughing operation on the workpiece using primarily a thermal material removal mechanism and is further configured to provide an electrodischarge finishing operation on the workpiece subsequent to the electroerosion roughing operation.