Corrosion Protection of Steel Parts in Aircraft by Zn-Mn Alloy Electrodeposits

Document Type : Original Article


1 Assistant Professor, Military Academy, 33 Gen. Pavle Jurisic Sturm St., Belgrade, Serbia.

2 Associate Professor, Faculty of Technology and Metallurgy, University of Belgrade, P.O.Box 3503, YU-11120 Belgrade, Serbia.

3 Senior researcher, Military Technical Institute, Ratka Resanovica 1, Belgrade, Serbia.


Electrodeposited Zn-Fe, Zn-Co and Zn-Ni alloy coatings are widely used for corrosion protection of steel nowadays. Several authors have reported that in aggressive environments, such as atmosphere containing SO2 and chloride compounds, Zn-Mn alloy coatings can have even better corrosion resistance. Besides, these alloys possess high hardness and they can easily be painted. Good characteristics of Zn-Mn alloys suggest their possible application in protection of steel parts, especially in automobile and aircrafts. In the last ten years, three new types of electrolytic solutions for electrodeposition of Zn-Mn alloys were proposed, namely acidic chloride and sulphate and alkaline pyrophosphate solution. The scope of this work was to compare the corrosion protection ability of Zn-Mn alloy coatings electrodeposited under various parameters, such as type of electrolytic solution, concentration of metal ions in solution and deposition current density. Recording of corrosion potential and salt spray chamber measurements were used to investigate the corrosion stability of Zn-Mn coatings. It was concluded that Zn-Mn alloy had better corrosion resistance than pure Zn, due to the formation of compact protective-passive layer in chloride containing media. Among various Zn-Mn electrodeposits, the best corrosion behavior was obtained for the ones deposited from chloride solution, at current densities between 3 and 8 A dm-2.