Post-Wear Corrosion Evolution of Nanocrystalline Ni Coatings with Sliding-Induced Crystallographic Texture

Nanocrystalline Ni coatings have attracted attention as protective materials for tribological applications in chloride-containing environments, but their corrosion response after prior sliding damage remains unclear. Here, electrodeposited nanocrystalline Ni coatings were subjected to circular sliding wear at 0.30 and 0.03 m/s. The specimens were selectively sealed to define an exposure window in which the 0.30 m/s wear track, the 0.03 m/s wear track, and the as-deposited surface were simultaneously exposed to a 3.5 wt.% NaCl solution for up to 120 h. Corrosion evolution was followed quasi-in situ at the same locations after successive immersion intervals using SEM and surface topography analysis. The 0.30 m/s track showed faster degradation and more severe localized corrosion, whereas the 0.03 m/s track remained groove-dominated with weaker pitting. TEM and four-dimensional scanning transmission electron microscopy (4D-STEM) revealed grain growth in both wear tracks. Sliding at 0.30 m/s induced a orientation along the normal direction, while the 0.03 m/s track largely retained the and texture components along the normal direction, similar to those of the as-deposited coating. The enhanced localized corrosion of the 0.30 m/s track is interpreted as the coupled consequence of wear-induced surface damage, debris-layer instability, grain coarsening, and crystallographic texture redistribution.