Macro & micro-feature fabrication on external cylindrical surface using perimetric electrical discharge texturing

Abstract

Abstract Machining of thin walled lesser stiff rotationally symmetric components is quite challenging. Electric discharge texturing is one among many of the material removing texture fabrication techniques. Extensive research has been performed for wire electric discharge machining by various researchers but so far very little effort has been made for electric discharge texturing on cylindrical surface. No one has attempted for texturing on thin walled cylindrical components. In the present study, preliminary trial experiment was conducted to evaluate suitability of newly developed Electric Discharge Machining technique i.e. Perimetric Electric Discharge Texturing (PEDT). A Perimetric Work Support & Drive System (PWSDS) was developed for Die sinker EDM to perform texturing on thin walled difficult to machine circular components used in aviation, automobile and heat transfer applications. Experimental setup was prepared for ENC-35 (Die sinker EDM). Trial experiment were performed at low current on Aluminium alloy (EN AW-6082-AlSi1MgMn) tube using copper electrode. Process was investigated for the effect of current and current density on MRR, surface roughness and geometrical accuracies (circularity, concentricity). The dielectric Dearomatized hydrocarbon fluid EDM100 was applied through nozzle to flush out the material removed by melting and evaporation. It was found that very small current quickly removes a very thin layer of the surface material without much damage to the base metal and improves the surface finish. The circularity is found to be dependent upon the run out accuracy of the spinning drive wheel. PEDT proves out to be most promising method of metal removing texturing technique specially for lesser stiff typical components.