Influence of alloying additives on corrosion and hydrogen permeation through commercial aluminium in alkaline solution

The influence of alloying additives on the extent of corrosion and hydrogen permeation through aluminium of different grades such as 2S, 3S, 26S and 57S, in 0.01 M NaOH has been investigated using weight loss measurements and electropermeation. It is found that the extent of self corrosion and hydrogen permeated through different grades of commercial aluminium follow the order: 3S > 2S > 26S > 57S. The influence of incorporating zinc and indium either alone or in combination on self corrosion and permeation current has also been studied. It is found that ternary alloys of both 26S and 57S containing zinc and indium give considerably lesser values of self corrosion rate and permeation current.