Response surface methodology optimization of electroplating parameters for Co/CeO2 composite coatings with enhanced corrosion and wear resistance
Faroogh Sabze Var, Shayan Sarraf, S. Rastegari, Mansour Soltanieh
Abstract
This study explores the electrodeposition of Co and Co/CeO 2 composite coatings to investigate corrosion and wear resistance. The process was optimized using Response Surface Methodology (RSM) under Pulse Reverse Current (PRC) mode to optimize CeO 2 incorporation. Coatings were deposited at various current densities (20–80 mA.cm -2 ) and CeO 2 concentrations (5–35 g.L -1 ). Surface morphology, microstructure, and phase composition were analyzed using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Corrosion resistance was assessed in Hanks’ solution, and wear behavior was evaluated via pin-on-disk testing. RSM analysis identified the interaction between current density and CeO 2 concentration as the most significant factor in co-deposition. CeO 2 incorporation refined the grain structure and enhanced microhardness. Potentiodynamic polarization demonstrated acceptable performance for Co/CeO 2 coatings, with a corrosion current density of 3.6×10 -6 A.cm -2 . Wear tests revealed the lowest wear loss (1.20 mg) for Co/CeO 2 , surpassing Ti6Al4V. While Co/CeO 2 composite coatings exhibited superior wear resistance, their corrosion behavior was comparatively lower than Ti6Al4V, indicating potential applicability in environments where mechanical performance is of greater importance.