Dense nanoarrays LDHs film evenly dividing the Cl− diffusion path into longitudinal microchannels in favor of quasi-uniform corrosion of biomedical magnesium alloys

Abstract

The correlation of orientation-controlled LDHs-sheet on pitting susceptibility and stability was investigated. The LDHs-array film (ab-plane perpendicular to substrate) was constructed by pre-nucleation coupled complex-assisted hydrothermal growth, where LDHs microcrystals uniformly grown face-to-face into nano-array film in a dot-line-flake growth manner. The results demonstrate that ab-plane parallel LDHs film tends to exhibit filiform rather than pitting corrosion; ab-plane vertical LDHs film, Cl− selectively penetrating/attacking extreme intersect-gaps, emerges pitting corrosion in advance. Interestingly, the LDHs-array film appears dense but tiny corrosion pits (quasi-uniform corrosion), attributing to uniformly dividing the Cl− diffusion path into numerous narrow longitudinal microchannels by its flakes.