Effect of Microstructural Modifications on the Corrosion Resistance of CoCrFeMo<sub>0.85</sub>Ni Compositionally Complex Alloy Coatings

A compositionally complex alloy (CCA) was developed in powder form and applied as a coating onto a carbon steels substrate by using thermal spray. The purpose of this study was to investigate the effect of microstructural modification induced by using two different powder production methods, mechani...

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Bibliographic Details
Main Authors: Francesco Fanicchia, Ioana Csaki, Laura E. Geambazu, Henry Begg, Shiladitya Paul
Format: Article
Language:English
Published: MDPI AG 2019-10-01
Series:Coatings
Subjects:
Online Access:https://www.mdpi.com/2079-6412/9/11/695
Description
Summary:A compositionally complex alloy (CCA) was developed in powder form and applied as a coating onto a carbon steels substrate by using thermal spray. The purpose of this study was to investigate the effect of microstructural modification induced by using two different powder production methods, mechanical alloying and gas atomisation, onto the corrosion resistance of the coatings for a CoCrFeMo<sub>0.85</sub>Ni composition. The evolution of microstructure from powders to coatings was analysed using scanning electron microscopy coupled with energy-dispersive spectroscopy and X-ray diffraction. In order to evaluate the corrosion performance of the coatings, electrochemical corrosion tests were performed in a 3.5 wt % NaCl solution at pH = 4. The study demonstrates that the powder production method has a significant influence on the phase composition and, in turn, corrosion behaviour of the resulting coating, with the gas atomising route imparting better corrosion resistance properties. Nevertheless, the appearance of the face-centered cubic (FCC) phase characteristic of the CoCrFeMo<sub>0.85</sub>Ni alloy within the coating produced from the mechanically alloyed powder, opens the possibility for this powder manufacturing technique to effectively produce compositionally complex alloys.
ISSN:2079-6412