Analysis of effect of voltage on surface texture in electrochemical grinding by autocorrelation function

The major difficulty faced in electrochemical grinding (ECG) of composite materials is poor surface integrity because of differential dissolution rates of different ingredients present in those materials. In the present investigation an experimental study, organized by statistical procedure, was made to evaluate the effect of the major controllable parameter ‘voltage’ on the surface finish of P-20 grade cemented carbide. The surface roughness data were analyzed for different voltages. The values of autocorrelation function for different values of lag period were calculated. The periodicity and randomness of surface roughness were identified. They are compared with the similar observations on the conventional diamond grinding of the same material in ECG environment with no application of voltage. A non-dimensional parameter was introduced for that purpose and was termed as ‘periodicity to randomness index’. An attempt was made to find out the relative contribution of the electrolytic dissolution under the chosen experimental conditions.