Abstract:
AlCoCrFeNi+
xwt%VC(
x=0,6,9) high entropy alloy composite coatings were prepared on Q235B steel substrate by laser cladding technique. The microstructure, phase, microhardness, wear resistance and corrosion resistance of the coatings were systematically investigated by scanning electron microscope, energy dispersive spectrometer, X-ray diffraction (XRD), Vickers hardness tester, electrochemical workstation, and friction and wear tester. The results show that the addition of VC causes the phase composition of the coating to transform from a single BCC phase structure to the BCC-FCC dual-phase coexistence structure, inducing lattice distortion and grain refinement. And the hardness of the AlCoCrFeNi coatings is about 3.6 times of that of the substrate. After adding VC, the hardness of the coating changes little, the wear resistance of the coating is significantly enhanced, and its corrosion resistance is effectively improved. With the increase of VC content, the corrosion voltage of the coating gets higher, and the corrosion current density gets lower. When 9% VC is added, the coating exhibits the best wear resistance, with a the rate is 66.5% lower than that of the coating without VC. The coating also has the highest corrosion voltage and the lowest corrosion current density, demonstrating the best corrosion resistance. This study provides experimental support for improving the wear resistance and corrosion resistance of AlCoCrFeNi high-entropy alloy coatings.