Influence of Silica on Microstructural Modification of Electrical Discharge Composite Coating and its Wear Performance

Abstract

Electrical discharge coating a significant process of depositing alloying materials over the surface for improved wear resistance. In present investigation reinforcement of silica with a varying concentration in working fluid together with carbon over duplex stainless steel and their effects on coating formation, porosity, microstructure, microhardness and wear resistance properties under the elevated temperature of 600 °C has been investigated. While the silica percentage increases the surface roughness, deposition of carbon and porosity of the coating are reduced, with varying decarburizing depth, frictional coefficient and modified microstructure having finer in phase transformation beneath the coating. The carbide bands the microstructure of the pyrolysis carbon retains outstanding metallurgical bonding, grain refinement and makes hard metal matrix composite layer towards high temperature wear resistance. The frictional coefficient at higher temperature reduces while the carbon percentage increases the specific wear rate due to oxides that minimize the third body wear.