Investigation of characterization and corrosion resistance of electrochemical and PVD coated zamak 5 alloy

Zamak 5, a zinc-based die-casting alloy, is widely used in various industries due to its mechanical strength, corrosion resistance, and aesthetic appearance. However, production processes and service conditions can lead to several surface and coating- related issues. Common coating problems observed in Zamak 5 include surface roughness, porosity, poor adhesion of the coating layer, corrosion propagation beneath the coating, and cracking due to differences in thermal expansion between the coating and the substrate. In this study, copper-nickel-chromium electroplating and physical vapor deposition (PVD) methods were applied to improve the surface quality of Zamak 5. The effects of coating materials and process parameters on the microstructure, surface roughness, and corrosion resistance of Zamak 5 were evaluated through copper-nickel- chromium electroplating. In the PVD coating studies, the influence of process parameters such as preheating and coating temperature on surface performance was investigated. As a result of the chemical coating processes, samples with chromium as the top layer exhibited the best surface properties. Among the PVD applications, coatings performed at 70 °C provided superior surface quality and a more homogeneous coating structure compared to other temperature conditions.