Design and characterization of FeCrCoAlMn0.5Mo0.1 high-entropy alloy coating by ultrasonic assisted laser cladding

In this work, FeCrCoAlMn0.5Mo0.1 high-entropy alloy (HEA) coating was successfully synthesized on 316L stainless steel by ultrasonic assisted laser cladding. The effect of dilution rate on the phase composition of FeCrCoAlMn0.5Mo0.1 coatings was investigated by thermodynamic calculation, solidification simulation and microstructure characterization. The mechanical properties, tribological behavior and corrosion resistance of FeCrCoAlMn0.5Mo0.1 coating prepared under optimal dilution rate were also characterized in detail. The results show that the increase of dilution rate results in the transition of single solid solution (BCC) into dual-phase solid solution (FCC and BCC) of FeCrCoAlMn(0.5)Mo(0.1)coating. The TEM analysis reveals that FeCrCoAlMn0.5Mo0.1 coating with optimal dilution rate (similar to 27.3%) is virtually composed of disordered BCC phase and ordered BCC (B2) phase. The spinodal decomposition structure and numerous dislocations were found in the grains. The average microhardness of FeCrCoAlMn0.5Mo0.1 coating is similar to 624.1 HV, which is more than 2.6 times higher than that of the substrate. The wear resistance of FeCrCoAlMn0.5Mo0.1 coating was found significantly improved almost 4 times than that of 316L stainless steel. The passive current density of FeCrCoAlMn0.5Mo0.1 coating is reduced by an order of magnitude compared with that of 316L stainless steel, proving the better corrosion resistance of FeCrCoAlMn0.5Mo0.1 coating. (C) 2020 Elsevier B.V. All rights reserved.