Microstructure and corrosion property of CrMnFeCoNi high entropy alloy coating on Q235 substrate via mechanical alloying method

Abstract

The CrMnFeCoNi high entropy alloys with equal atomic ratio is one of the most notable and promising alloys that has been studied by researchers so far. However, there are only a few papers that has been published on CrMnFeCoNi high entropy alloy coating. In this paper, the equal atomic ratio CrMnFeCoNi alloy coating was synthesized on the Q235 steel substrate by mechanical alloying method. The experiment for preparing CrMnFeCoNi HEA coating involved two steps: First, high-entropy alloy powder was prepared. Then the Q235 substrate was put into the prepared powder and followed by a milling process for 10 h, after that the high entropy alloy coating was successfully prepared. The microstructures of the coating were characterized by scanning electron microscope (SEM), the phase structure and chemical composition of which were analyzed by X-ray diffraction (XRD) and energy dispersive spectrometer (EDS) respectively. The as prepared CrMnFeCoNi powder and the final coating are both single face-centered cubic (FCC) solid solutions. The thickness of the coating is 180 μm and showed a good bonding performance with the substrate. The elements in the coating were evenly distributed without component segregation. The corrosion behaviour was tested by the dynamic potential polarization method. The results showed that the CrMnFeCoNi coating has better corrosion resistance than the substrate in 3.5 wt % NaCl solution.