Tribocorrosion characteristics of Cerium oxide nanoparticles included lanthanum zirconate coatings on piston material (Al 4032) by high-velocity oxygen fuel thermal spraying

Abstract The study sought to assess the tribocorrosion behavior of cerium oxide nanoparticles with lanthanum zirconate coatings applied to piston material by the high velocity oxy fuel thermal spraying technique. Al 4032 aluminium samples were coated with lanthanum zirconate. Additional specimens were created with 5% by wt. cerium oxide nanoparticles incorporated lanthanum zirconate coatings. All coated samples were tribocorrosion tested in a 5 wt% NaCl solution. Micro-scratch tests were conducted to study the traction force and coefficient of abrasive friction. The electrochemical and tribological properties of the coatings were studied. Variations in cathodic and anodic voltages were used to study changes in corrosion current density and electrochemical impedance spectroscopy before and after wear. It was found that including cerium oxide nanoparticles into the lanthanum zirconate coating resulted in significantly decreased corrosion current density during simultaneous wear and corrosion when compared to uncoated Al 4032 aluminum. Under anodic circumstances, the electrochemical impedance of the nanoparticle-enhanced coating remained low, but the impedance of Al 4032 aluminum decreased. In terms of tribological performance, the friction coefficient of Al 4032 aluminum was sensitive to applied potential, but the nanoparticle-reinforced coating remained stable except at high potential. Both samples saw a linear rise in material volume loss as the voltage increased, whereas Al 4032 aluminum showed significantly higher wear and corrosion-induced loss.