Laser cladding of FeCoNiCrAlCu_xSi_0.5high entropy alloys on AZ31 Mg alloy substrates

S. Maney & Son Ltd. To improve the inherent low hardness and poor corrosion resistance of an AZ31 Mg alloy, FeCoNiCrAlCuxSi0.5high entropy alloys (HEAs) were clad on Mg alloy substrates using a preplaced powder bed method and laser re-melting. The results showed that coating dilution by Mg was limited to the interface regions. Similarly, except for a small amount of Cu of the HEA entering into the Mg substrate to a shallow depth, no other HEA elements were found in the re-melted zone of the substrate. The stability of FeCoNiCrAlCuxSi0 5HEAs with the addition of Mg was evaluated based on the change of the Gibbs free energy. The results showed that the original HEAs without Mg were stable alloys. The microstructure of the FeCoNiCrAlCuSi0 5and FeCoNiCrAlCu0 5Si0 5clads consisted of only bcc and fcc simple solid solution phases without intermetallic compounds. With regard to properties, the HEA clads have high hardness and high corrosion resistance.