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Student questions on electropolishing

2004

Why metal surfaces can be polished in an electrolytic cell, based on electrochemical principle? (as reference to a copper polishing cell) And why is it possible to remove micro-elevations on a specimen surface selectively? What is the effects of voltage of a DC source, temperture and electrolyte movement on polishing quality?

Andy Li
student - Singapore

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2004

Metal can be oxidized from metallic state to ionic state by the removal of electrons. Thus, is you make the copper anodic, it will start dissolving. The high points are closer to the cathode and represent a lower resistance path than the low points, so more current will flow to them and they will dissolve preferentially, thus smoothing the surface. For a discussion of DC sources, temperatures, electrolytes, and agitation you need a book like The Electroplating Engineering Handbook.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey