question_answer

  How can a layer of aluminium oxide on an aluminium object be made thicker? What is this process called?

Answer:

                  Aluminium develops a thin oxide layer when exposed to air. This aluminium oxide coat makes it resistant to further corrosion. The resistance can be improved further by making the oxide layer thicker. This process is called anodizing. During anodizing, a clean aluminium article is made the anode and is electrolyzed with dilute sulphuric acid. The oxygen gas evolved at the anode reacts with aluminium to make a thicker protective oxide layer. This oxide layer can be dyed easily to give aluminium articles an attractive finish.