Rapid fabrication of the continuous AlFeCrCoNi high entropy alloy coating on aluminum alloy by resistance seam welding

Abstract The continuous AlFeCrCoNi high entropy alloy coating was firstly fabricated on aluminium alloy by resistance seam welding. During welding, the coating was formed rapidly under the effect of instantaneous joule heating and the pressure. The gradient temperature transformed the nanocrystalline AlFeCrCoNi powder into the AlFeCrCoNi HEA coating consisted of body-centered-cubic and face-centered cubic structures. According to the calculation and experimental results, the welding process was not brought the negative affect to the substrate and only a certain amount of aluminum element penetrated into the coating. The average thickness and hardness of the coating were 420 µm and 715HV0.2, respectively. Compared to A6061, the coating exhibited excellent wear-resistance in dry, deionized water and 3.5 wt% NaCl solution conditions. The environment played an important role in the wear behaviour of the AlFeCrCoNi HEA coating. Meanwhile, the corrosive wear of the AlFeCrCoNi HEA coating was proved to be beneficial to reduce the wear rate.