Detalhes do Documento

Layered double hydroxides represented by the general formula [M2 2+M3+(OH)6]+X1/n n-.zH2O are being researched as anion-exchange materials with interesting intercalation chemistry that accommodate a wide range of applications, including corrosion resistance. In this work, it is shown that the formation of layered double hydroxides (LDHs) on the surface of copper-rich Al alloys promotes corrosion resistance. For that purpose a LDH of the type [M+M3+ 2(OH)6[An- 1/n].zH2O], where the intercalated cation is mono-valent Lithium is studied. In Aluminium 2024-T3 or Al-Li 8090, corrosion inhibition was achieved as a result of the formation of a LDH film: Al2Li(OH)7.2H2O or Al2Li(OH)62CO3.zH2O according to the precursor solution used. LDHś covered the entire surface of the mentioned alloys, mitigating the galvanic action between the matrix and Cu rich phases, usually responsible for corrosion of the localized type. Inhibition is demonstrated to be under diffusion control. Layered double hydroxides were characterised using Xray diffraction, FTIR and SEM. The role of copper is examined using an approach that includes a study on pure copper samples