Chemical Smoothing of Rough Metal Surfaces

Abstract

A chemical etching method is investigated as a possible approach to smoothing metal surfaces automatically. In a chemical etching process metal is removed due to chemical reaction and the dissolved species are transported away from the surface mainly by diffusion. Controlled dynamics introduced to the etchant motion provide the conditions necessary to perform preferential material removal such that an irregular surface is smoothed. A simplified model for the smoothing process based on fundamental mass transfer understandings is presented. Experimental results of smoothing electric discharge machined 440 stainless steel specimens are also presented. This work is motivated by the need to develop a cost effective way to manufacture molds during secondary processing.