Corrosion inhibitors aluminium alloys immersed

The various routes that have been examined to enhance the corrosion resistance of anodized aluminium using cerium compounds, such as nitrates or sulphates, include pre- and post-treatments and anodizing with cerium species added to the bath formulation (the addition of cerium to commercial alloys for corrosion protection has not been reported). Each of these approaches has revealed some benefits in short-term laboratory corrosion tests. However, the imderlying mechanisms of corrosion protection are imclear. Corrosion inhibition of aluminium alloys caused by cerium species is well-established, with cerium acting as a cathodic inhibitor at intermetallic particles (Amott et al, 1987). Cerium oxide/ Itydroxide precipitates in response to the increase of pH at cathodic particles as the alloy briefly corrodes following its immersion in the environment. The precipitates stifle further corrosion by hindering the reduction of oxygen and water. 

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