Electric Discharge Coating (EDC), progressed from Electric Discharge Machining (EDM), is earning recognition as an effective coating technique for enhancing the functional qualities of engineered materials. The present review article provides an overview of the fundamental aspects of the EDC process, including its working principle on material transfer mechanism and the influence of key discharge parameters on coating characteristics. The role of W-Cu and WC-Cu tool electrode materials is highlighted with particular attention to their properties and their influence on deposition behaviour and the resulting coating quality. The development of improved electrodes employing powder metallurgy is reviewed, with a particular emphasis on tungsten-copper (W-Cu) and tungsten carbide-copper (WC-Cu) composites. Their characteristics, performance and applications in improving wear and corrosion resistance are thoroughly investigated. Furthermore, the performance of green, sintered and semi-sintered electrodes is evaluated. Finally, current difficulties, research gaps and future directions are presented to assist the progress of EDC technology.
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