Study the Surface Characteristics of Cryogenically Treated Tool-Electrodes in Powder Mixed Electric Discharge Machining Process

摘要

The present experimental study has been focused to evaluate surface characteristics of cryogenically- treated (shallow/deep) tool-electrodes using powder mixed electric discharge machining. Due to the continuously growing demand of complex and precise parts, tool-electrodes have its own importance, because quality of the machined parts depends upon the surface quality of electrode. On the analogy, eighteen experiments were performed based on L_(18) orthogonal array of Taguchi's methodology, which consist eight input parameters. Analysis of variance (ANOVA) was employed to designate the level of significance of input parameters. Electrode material has maximum influence followed by the current and pulse on-time on electrode finish. The combination of optimum factor's level of identified parameters was determined using Taguchi's technique for single response. Confirmation experiments were conducted using suggested optimal parameters with its respective level to minimize the tool-electrode surface roughness. Surface characteristics of tool-electrodes were analyzed using Scanning Electron Microscope (SEM) and Energy Dispersive Spectrograph (EDS) followed by X-ray diffraction (XRD) on selected samples. The results exposed that significant material transfer from workpiece and powder mixed dielectric fluid in compound form on the tool surface.