Study on magnetic performance and corrosion resistance of CoPtWP coating prepared by electrodeposition

Electrodeposition is used to prepare the Co, CoPt, CoPtW, and CoPtWP coatings on the surface of pure copper. The association between magnetic performance, corrosion resistance, surface morphology, roughness, thickness, and electrodeposition process is investigated by contrasting the four electrodeposited coatings. The deposition of cobalt and tungsten is discovered to be a type of induced codeposition. The chloroplatinate and hypophosphate ions receive electrons to reduce to the CoPtWP alloy at the surface of the CoPt coating. The adding of WO42- and H2PO2- ions in the plating solution is beneficial to promote the electrochemical reaction near cathode surface. The surface of Co coating shows leaf-like and loose morphology with largest surface roughness leading to poor magnetic performance and corrosion resistance. However, the surface morphology of the CoPt coating, CoPtW coating, and CoPtWP coating is all compact with nodular structures. With the least surface roughness and greatest thickness, the CoPtWP electrodeposited coating exhibits superior magnetic performance and enhanced corrosion resistance.