Abstract
Double layered porous oxide films were formed on aluminum by two step anodizing at an initial current density (i1) in a H2SO4 solution (S-layer) and again at a second current density (i2) in a H2C2O4 solution (O-layer). The anodized specimens were re-anodized in a neutral borate solution at constant current density to follow the change in anode potential (E) with time (t). The geometrical structre of the double layered films was estimated by analysing the E-t curves (pore-filling method).It was found that the structure of the O-layer was dependent on i2, but independent of the structure of the S-layer formed at i1. Pore-widening in the S-layer was observed to take place by chemical dissolution during the formation of the O-layer.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
