Evaluation of the Electrochemical Behavior in Acid Media of HVOF-Spray Alloy Coatings

In the aircraft and aerospace industry, coatings obtained by thermal spraying HVOF are use in some components of steam turbines, due to the passage of gases at high temperatures cause of the rotation of the wing which is subjected to severe static and dynamic load, usually associated with microstructure degradation mechanisms as corrosion, wear and creep. The MCrAlY coating ( M = Co or Ni ) type applications are used to provide wear and also corrosion resistance. In this work a HVOF gun was used to prepare a MCrAlY coating which has been subjected to two electrochemical techniques: polarization resistance and cyclic polarization curves in order to obtain the behavior of the rate of corrosion in acid and neutral media. The results show that the acid factor in the solution play an important role in the corrosion resistance of MCrAlY coating applied by HVOF thermal spraying.