Effect of Ti content on structure and properties of Al2CrFeNiCoCuTix high-entropy alloy coatings

The Al2CrFeNiCoCuTix high-entropy alloy coatings were prepared by laser cladding. The structure, hardness, corrosion resistance, wear resistance and magnetic property were studied by metallurgical microscope, scanning electron microscopy with spectroscopy (SEM/EDS), X-ray diffraction, micro/Vickers hardness tester, electrochemical workstation tribometer and multi-physical tester. The result shows that, Al2CrFeNiCoCuTix high-entropy alloy samples consist of the cladding zone, bounding zone, heat affected zone and substrate zone. The bonding between the cladding layer and the substrate of a good combination; the cladding zone is composed mainly of equiaxed grains and columnar crystal; the phase structure of Al2CrFeNiCoCuTix high-entropy alloy coatings simple for FCC, BCC and Laves phase due to high-entropy affect. Ti element promotes the formation of a BCC structure in a certain extent. Compared with Q235 steel, the free-corrosion current density of Al2CrFeNiCoCuTix high-entropy alloy coatings is reduced by 1-2 orders of magnitude, the free-corrosion potential is more “positive”. With the increasing of Ti content, the corrosion resistance of Al2CrFeCoCuNiTix high-entropy alloy coatings enhanced in 0.5 mol/L HNO3 solution. Compared with Q235 steel, the relative wear resistance of Al2CrFeCoCuNiTix high-entropy alloy coatings has improved greatly; both the hardness and plasticity are affecting wear resistance. Magnetization loop shows that, Ti0.0 high-entropy alloy is a kind of soft magnetic materials.