Investigating on coating morphology and chemical composition of Al-A380 and Al-B390 coated by anodic oxidation method

Inthis research، A380 and B390 aluminum alloys with lowest and highest silicon content were casted and coated by anodic oxidation (anodizing) method. The conditions of bath were adjusted 12% volume sulfuric acid، 2-4℃ temperature، 1. 2 A/dm2 current density and fixed time on20 and 60 min. So the effect of alloyon thickness، surface morphology and chemical composition of coating was studied. It is found that increase of silicon content leads to decrease rate of growth thickness and increase non-uniformity، which it has near linear depending to silicon content of alloy. As well as، surface microcracks increased by increasing of coating time andby increasing silicon content.