Machine And Method For Electrochemically Polishing Indentations Within An Aluminum Wheel

Abstract

A machine for electrochemically polishing indentations within the wall of an aluminum workpiece, such as a wheel, has a cathode attached to an upper platen. The workpiece is mounted upon a lower platen which acts as an anode. Electrolyte is passed between the cathode and the anode while simultaneously a current is applied which passes through the cathode and the anode. The current is selectively pulsed to maximize polishing but at the same time to permit the flushing away of residual material and to cool the cathode and the workpiece.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates generally to electrochemical polishing and more specifically to electrochemically polishing aluminum wheels.[0003]2. Description of Related Art[0004]Electrochemical machining (ECM) is a process for removing material from a metal workpiece to impart a smooth surface which appears to be polished. Such a process takes place using an electrolyte having a high ionic strength. The workpiece to be machined serves as the anode and the electrode of the electrochemical machining apparatus serves as the cathode. In the polishing process an electric current runs between the anode and the cathode. Under these conditions, the electrode serves as a shaping tool. The workpiece, which serves as the anode, dissolves locally, for example, in the form of metal hydroxide while hydrogen is formed at the electrode surface. This electrochemical machining method enables patterns or arbitrarily shaped holes to be fo...

AI Technical Summary

Benefits of technology

[0007]One embodiment of the subject invention is directed to a machine for electrochemically polishing indentations of known geometry within the wall of an aluminum workpiece, such as a wheel. The workpiece space defines the space in which a workpiece would occupy in the machine. The machine has an upper platen with a cathode extending from the upper platen, wherein the cathode is associated with an indentation and, wherein the cathode has a shape similar to that of the indentation but smaller and is adapted to be positioned adjacent to the indentation to define a gap therebetween for the introduction of an electrolyte between the cathode and the indentation. A lower platen is aligned with the upper platen, wherein the lower platen is adapted to receive the wheel and, wherein the upper platen and the lower platen are movable relative to one another such that, in a

Problems solved by technology

However, electrochemically polishing large workpieces requires a large current and in the past, as a result of such a limitation, electrochemical polishing has been limited to relatively small surfaces.

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