• • PI sealing of MAO defects yields contact angles of (114.6±4.2)° and (110.1±3.3)°, transforming the hydrophilic ceramic surface into a hydrophobic barrier that reduces electrolyte wetting and delays corrosive ingress; this directly addresses the failure mode where micro-pores act as capillary pathways for chloride attack.
• • MAO/PI-CeO2 coating maintains high |Z|0.01 Hz after long-term electrochemical testing and survives 40 days of salt spray with only slight local corrosion, whereas unsealed MAO fails rapidly; this 40-day stability threshold is critical for automotive and aerospace components requiring multi-year service intervals without maintenance.
• • CeO2 doping densifies the PI matrix and generates Ce3+/Ce4+ species that react with OH– to form insoluble precipitates that seal micro-defects and suppress cathodic reactions; this self-healing mechanism provides active corrosion protection beyond passive barrier effects, reducing corrosion current density by orders of magnitude versus MAO/PI alone.
• • CeO2 incorporation reduces wear depth and width in 3D profilometry, with PI acting as a solid lubricant and CeO2 enhancing load-bearing capacity and structural integrity; this dual-phase strategy lowers plastic deformation during sliding contact, extending component life in tribological applications where MAO coatings alone suffer from brittle fracture and abrasive wear.