Effects of lanthanum on the microstructure, electrochemical behavior, and anti‐corrosion properties of zinc–copper–titanium alloy in 3% sodium chloride solution

Abstract

SEM analysis shows that trace amounts of La in Zn–Cu–Ti alloy can eliminate dendritic segregation and produce uniform organization. Analyses of Tafel polarization curves and EIS show that La can obviously improve the corrosion resistance of Zn–Cu–Ti alloy by two features: (i) La oxide film has strong barrier properties; (ii) with an increase in La content, the thick skeletal dendrite ϵprimary crystal phase disappears and the more refined and dispersed ϵII phase is generated, leading to a decrease in the active cathode area. Zn–Cu–Ti–0.5La alloy has the best corrosion resistance. The corrosion of the investigated alloys is mainly selective.