THE EFFECT OF Y ON THE PERFORMANCE AND MICROSTRUCTURE OF FeCoCrNiMnTi0.6 HIGH-ENTROPY ALLOY COATINGS

In this study we prepared FeCoNiCrMnTi0.6YXwt% (x=0.5, 0.75, 1, 1.25) high-entropy alloy coatings on c45 steel substrates using the laser-cladding method. The microstructure and properties of the cladding layers were investigated. The results indicated that the cladding layers exhibited good metallurgical bonding with the substrate, with the coatings comprising an FCC phase matrix accompanied by the precipitation of the Laves phase. With the addition of Y, the grain size of the coatings was gradually refined. Owing to the combined effects of grain-refinement strengthening, second-phase-precipitation strengthening, and solid-solution strengthening, the microhardness of the coatings increased, reaching up to twice that of the substrate. As the grains were refined, the wear resistance of the coatings initially increased and then decreased, with the optimal performance observed at x=1. The coatings also exhibited excellent corrosion resistance, which improved with increasing Y content.