Influence of electroplating parameters on microstructure and amount of ceramic particle deposition in Ni-Co-CeO2-ZrO2 composite coating

Austenitic stainless steels are high performance steels that have various applications in solid oxide fuel cells and boiler tubes under high temperature operating conditions. The Cr2O3 oxide layer formed on the steel surface becomes unstable at high temperatures and reduces the oxidation resistance of the steel. Therefore, protection of these steels at high temperatures is essential. Therefore, one of the best effective ways to extend the life of these components against oxidation is by applying protective coatings. In this research, Ni-Co-CeO2-ZrO2 composite coating was created by direct electrodeposition on the surface of AISI 304 austenitic stainless steel. In order to obtain proper coating, the effect of current density, pH and concentration of ZrO2 in the bath was investigated. To create the optimum deposition, the bath parameters were investigated. Influence of ZrO2 content (5, 10 and 25 g/L), current density (15, 20, 25 and 30 mA/cm-2) and pH (3, 3.5, 4 and 4.5) on the deposition amount of ceramic particles and microstructure of the coating has been investigated. Scanning electron microscopy (SEM) and EDX analysis were used to determine the morphology. The results showed that with increasing ZrO2, the amount of ZrO2 deposition increased and the amount of CeO2 deposition decreased. Also, with increasing current density and pH, the amount of ZrO2 and CeO2 particles decreased.