On Some Aspects of Surface Formation in ECM

Abstract

The mechanism of surface formation in electrochemical machining (ECM) is not fully understood because of the complex heterogenous reactions possible in the inter-electrode gap. A complete understanding of the flow phenomenon can provide considerable information in this regard. Qualitative and quantitative analyses of surface profiles presented in this paper highlight the significant effect of the flow velocity on surface formation. The flow velocity significantly affects the short wavelength irregularities of the surfaces produced in anodic smoothing. At lower velocities, the workpiece grain size also influences the surface finish. The smaller grains yield better finish when the Reynolds number is below 10,000. The cathode reproduction is poor with increasing velocity but the overall finish is found to be good. Short wavelength irregularities present in the reproduced profiles reduce considerably with increasing flow velocity. Better reproduction is seen when the lay of the tool is across the flow. Such studies are significant in understanding the anodic smoothing and cathode reproduction, and these experimental results augment the theoretical models developed in this field.