A Study of Tribological Properties on Epoxy Resin Sealed 8YSZ Coating Under Various Environments

The tribological properties of epoxy‐sealed 8YSZ (8YSZ‐RE) coating in dry friction, deionized water, 0.1 mol L −1 ( m ) HCl, and NaOH solutions are comparatively studied. Its microstructure is characterized by scanning electron microscope (SEM), X‐ray diffractometer, and field emission scanning electron microscope. The friction and wear behaviors under various environments are conducted using a CSM ball‐on‐disc tribometer. The morphologies and mechanical properties of the worn surfaces are analyzed via SEM, 3D profilometer, nanoindentation, and optical microscope. The corrosion resistance of 8YSZ‐RE coating in 0.1 m HCl and NaOH solution is studied using by electrochemical corrosion tester. Results indicate that 8YSZ‐RE coating exhibited superior tribological performances in HCl and NaOH solution compared to deionized water and dry friction, mainly due to hydroxide layer formation on the worn surface. The liquid medium can remove the fine wear debris generated during friction, making it hard to gather on the worn surface. The friction coefficients of 8YSZ‐RE coating in NaOH and HCl solution are 0.26 and 0.14, respectively. The friction coefficient under dry sliding reaches a maximum of 0.66. The tribological performances of 8YSZ‐RE coating are best in a 0.1 m HCl solution. This is attributed to the presence of a hydrodynamic lubrication layer and its strong corrosion resistance.