Microstructure and properties of AlCrFeNiMoNb high-entropy alloys coating on ZM5 magnesium alloy prepared by high-velocity air fuel (HVAF) spray

Abstract

AlCrFeNiMoNb high-entropy alloys were successfully coated onto a ZM5 alloy using high-velocity air fuel spray (HVAF). Microcomputed tomography(micro-CT) results revealed that the porosity of the coating was only 0.36%, which demonstrates the coating has a highly dense structure. The average microhardness of high-entropy alloys coating was ＞ 5 times greater than that of the ZM5 alloy substrate. The changes of ZM5 substrate microhardness can be attributed to dynamic recrystallisation. The corrosion potential (Ecorr) of the AlCrFeNiMoNb coating was improved to approximately∼ − 0.998 V and the corrosion current (Icorr) of the coating significantly decreased by two orders of magnitude. The wear volume loss of the coating was ∼15 times lower than that of the ZM5 substrate. This indicates that the coating of the AlCrFeNiMoNb high-entropy alloy on the ZM5 substrate significantly improved the wear resistance of the ZM5 alloy. The ZM5 alloy surface had better corrosion and wear resistance properties owing to the protection offered by the AlCrFeNiMoNb high-entropy alloy.