Surface Modification by Electro-Discharge Machining Using Powder Metallurgy Electrode: A Review

Abstract

Since the last two decades, many novel techniques have evolved from electro-discharge machining (EDM). Among them, surface modification is one of the rigorously growing technologies by which surface properties can be enhanced by providing a layer having a thickness up to some microns on the workpiece. Existence of tool material on the machined surface after EDM was observed previously. This attribute of EDM makes it a benchmark in surface modification technology. Surface modification in EDM can be done by using different types of electrodes like solid, powder metallurgy (P/M), brush type, etc. This phenomenon can also be acquired by suspending powder particles into dielectric media. However, P/M electrode gives superior results with less effort and also proves to be economical. In this paper, a review has been made on using P/M electrode in surface modification during EDM. The different types of electrodes for surface modification, development of P/M electrode, types of layers generated and surface roughness improvement are critically analyzed. Also, some scope for future works is suggested here.

Experimental Investigation of Uncoated Electrode and PVD AlCrNi Coating on Surface Roughness in Electrical Discharge Machining of Ti-6Al-4V

“…It has considerably affected the surface roughness [27]. The difference between the thermal and electrical conductivity characteristics of the coated electrode material could affect the process of the spark formation and the energy of the generated sparks [22].…”

“…It was found that I was the most significant influencial parameter. The coated electrode can significantly improve MRR, TWR, Ra and machining accuracy [22]. The roughness of the machined surface with the Cu electrode has been selected to evaluate the effectiveness of coated Cu electrode including silver, nickel, zinc and epoxy.…”