Corrosion electrochemistry properties of thermally sprayed Zn–Cu–Ti coating in simulated ocean atmosphere

The electrochemical behavior of thermally sprayed Zn–Cu–Ti coating corroded in 3.5 wt% NaCl neutral salt spray for different days was investigated by electrochemical measurements. Electrochemical investigation shows that pitting corrosion occurs on the coating. Sacrificial anode protection and corrosion product protection play a dominant role. Coating corrosion can be divided into five stages: dissolution of surface oxides, deposition of corrosion products, stable dissolution of the coating, formation and development of occluded cell corrosion, and accelerated corrosion stage. The degradation mechanism and the role of galvanic protection of coating have been discussed by a proposed corrosion model.