Corrosion Behavior of Laser Remelted CoNiCrAlY Based Composite Coatings

Dragos Utu, Gabriela Marginean, Viorel-Aurel Serban, Cosmin Codrean

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DOI: 10.4236/eng.2010.25042                

Abstract

The corrosion behavior of High-Velocity Oxygen Fuel (HVOF) sprayed MCrAlY coatings obtained from CoNiCrAlY particles (wt. 8% Al) mechanically doped with Al2O3 nanopowder was investigated before and after laser remelting. The latter process was applied in order to achieve a homogeneous structure as well as better mechanical properties for the coating (reduced brittleness offered by the presence of the Al2O3 nanoparticles). Another important task of the laboratory investigations was the investigation of the corrosion behavior of the modified coatings. The results obtained from the potentiodynamic polarization measurements carried out in a chloride environment revealed an enhanced corrosion resistance of the laser remelted coatings comprising a refined microstructure. Microhardness measurements of the modified coatings revealed lower values in comparison with that of the samples in as-sprayed status. This observation leads to the assumption that a concomitant improvement of coatings ductility occurred as well.

Keywords

Laser Remelting, Conicraly Coatings, Corrosion Behaviour

Conflicts of Interest

The authors declare no conflicts of interest.

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