Comparison on corrosion-resistance performance of electro-thermal explosion plasma spraying FeAl-based coatings

Three kinds of FeAl-based plasma spraying coatings, FeAl, FeCrAl and FeCrAlRE coatings, were prepared by the electro-thermal explosion plasma spraying technique. The FeAl coating had a relatively worse needle-shaped microstructure, but the microstructures of the FeCrAl and FeCrAlRE coatings were greatly improved due to the addition of Cr and RE. The coatings had the metallurgical bonding with the matrix, and there was an evident transition layer within the matrix. The corrosion experiment results showed that in the three kinds of FeAl-based coatings, the corrosion-resistance performance of the FeCrAlRE and FeCrAl coatings was superior to that of the FeAl coating, especially the former. The reason lies in the addition of elements Cr and RE that improved the microstructure of the coatings.