Electrocontact Discharge Dressing of Metal-Bonded Diamond Grinding Wheel Utilizing a Hybrid Electrode

A hybrid rotary electrode has been developed as a means to realize a precision electrocontact discharge (ECD) dressing of the bronze-bonded diamond grinding wheel. The hybrid electrode consists of paired electrode blades whose gaps are filled with GC abrasive grains to prevent the electric discharge from concentration without an excessively eroded part, and the removal of resolidified bond material to be piled up on the bond matrix is also expected. From the experiments using two electrodes, the hybrid one and a pure electrode without GC abrasives, it has been clarified that the truing effect due to ECD is produced at the DC voltage higher than 20 V in the both methods; however, the hybrid method has an ability to generate a closer wheel surface topography than that obtained from pure ECD method and a finished roughness better than that obtained from the mechanical method using a GC cup truer is achieved if a DC voltage lower than 40 V is applied. The wear of the grinding wheel after hybrid ECDD is the same as that after pure ECDD, but no increase in power due to undesirable contact of the metal bond with the workpiece is observed