Grinding Finishing Merging Electropolishing on Hole-Wall Surfaces

The current study presents a method for finishing hole-wall surfaces, superior to that obtainable by traditional boring, using a simultaneous grinding and electropolishing process. A specially designed finishing tool, that includes a nonconductive grinding wheel and an electrode is employed in the process. The form of the tool and the machining process are different from those used in electrochemical grinding (ECG). A high power electrical supply is not required with this design of finishing tool because the axial feed allows for the use of a smaller interactive area between the electrode and the hole wall surface. The experimental results show that a high current flow combined with a fast axial feed rate for the tool is an important advantage to the finishing process. The finishing effect is better with high rotational tool speeds because discharge of the electropolishing dregs and grinding cuttings becomes more efficient and this is also advantageous to the grinding finishing process. Pulsed direct current can slightly improve the electrochemical finishing effect, but machining takes longer and this raises costs. A small edge radius on the electrode also provides more than sufficient discharge and gives a better finish. We intend to make a complete evaluation of the processing parameter data so that the use of this method for hole-wall surface finishing may be extended in the future. The combined application of grinding and electropolishing is crucial to this method and the specially designed tool and the new finishing process are highly efficient and inexpensive.