Corrosion assessment of an Al–Li–Ni–Sb–Ag base alloy in aqueous solutions

A corrosion assessment of as cast Al–Li–Ni–Sb–Ag alloy in 0.5 M NaCl and acid rain solutions using electrochemical techniques was performed. The macrostructure observed is composed of two of Al–Ni secondary phases formed by elongated grains and clusters of micro-rod formations of both Al 3 Ni ( β, θ ) and the AlSb (γ) phases, dispersed in the α–Al matrix. Li and Ag were incorporated in solid solution as well as the Ag 3 Al phase. Potentiodynamic results showed higher activity in the 0.5 M NaCl 100% solution than in the acid rain sample, wherein the alloy developed a protective corrosion product layer. Similarly, the long-term measurements showed R p kinetic values of up to 5.5 kOhm cm 2 initially, but decaying and stabilizing at around 2.5 kOhm cm 2 immersed in 95 vol.% of NaCl solution. Corrosion mechanisms are discussed in terms of activation and finite diffusion, and an inductive mechanism in acid rain. Results were complemented by X-Ray, scanning electron microscopy SEM and EDS characterization. Graphical abstract