Corrosion of Zn under fine size aerosols and droplets using inkjet printer deposition and optical profilometry quantification

In this study, corrosion of Zn surfaces caused by fine size acidified droplets (diameter ∼0.1–5 μm) was quantified. Fine size droplets of various chemistries were deposited using an unmodified inkjet printer and damage was quantified in terms of volume loss (ΔV) as determined through optical profilometry (OP). SEM–EDS and FIB milling were used to characterise corrosion products and perform cross-sectional analysis of surface oxides. Results show synergistic interactions between chloride concentration and the types of acids used for acidification. Corrosion under fine size droplets was found to be dependent on the initial volume of aerosols, oxygen diffusion, surface area to volume ratio and likely the microstructural features of the underlying metal.

► Fine size droplets (diameters ∼0.1–5 μm) were deposited on metal surfaces using inkjet printer.
► Volume loss caused by fine size droplets was quantified using optical profilometer (OP).
► Formation of oxygen and pH gradients is limited in fine size droplets due to fast access of oxygen.
► Incorporation of anions in final corrosion products is dependent on initial volume of the droplet.
► Oxides formed under fine droplets are highly porous therefore lack effective barrier properties.