Electric discharge coating process: a critical review with potential application

Abstract

Electric discharge coating (EDC) process is a competitive surface coating technology that alters the desired surface characteristics. EDC process deposits the material on the substrates from the sacrificial electrode by spark erosion process with the potential advantage of depositing any materials. This paper extensively reviews the work carried out in the EDC process and suggests areas of improvement for easy adaptability in industrial applications. Here, the variants of the EDC process, the route map for process parameter selection, the advantage over conventional methods, and coating characterization are discussed. The review sequentially presents the fundamental process, detailed analysis of tool and workpiece materials used, process parameters, and applications. EDC process has continued to be a key solution for many industrial needs, with the critical advantage of enhancing the substrate's serviceability and protecting against corrosion, thermal stress, and other adverse environmental conditions. The scope of the work is discussed in detail, with potential industrial and biomedical applications suggesting avenues for researchers and industrialists.