Enhanced Wear and Corrosion Properties of Mg-Li Alloys Achieved Through Laser Cladding of the Gradient High-Entropy Alloy Coating

Abstract

The research difficulties of preparing laser-cladded high-entropy alloy (HEA) coatings on Mg-Li alloys have been overcome through the gradient coating structure design. This work deposits a TiVCuAl/Cu-Al gradient HEA coating on Mg-Li alloys, significantly enhancing the alloy’s comprehensive surface properties.  The gradient coatings are characterized and analyzed for phase structures, microstructures, microhardness, wear and corrosion resistance. The protective coating primarily comprises V-rich BCC1, AlCu2Ti and Mg-rich BCC2 phases, with an average microhardness of 8.43 times that of the substrate (57.85 HV0.3), reaching 487.82 HV0.3. The wear volume loss of the protective coating is 0.09 mm3, only 5.42% compared to the substrate. Meanwhile, the corrosion potential and corrosion current density values of the protective coating are  -0.61 VSCE and 5.41×10-6 A·cm-2.

Keywords: Mg-Li alloy, Laser cladding, High-entropy alloy coating, Wear and corrosion properties