High-entropy TiAlCuFeNiV electrospark coating on titanium alloy Ti6Al4V

Abstract

High-entropy TiAlCuFeNiV coatings were prepared on titanium alloy Ti6Al4V by electrospark deposition with a non-localized electrode using an equimolar anode mixture consisting of granules of pure metals and alloys. During the ESD process, the electrical erosion of granules made of different metals proceeded with different intensities, which determined the ratio of metals in the coating. The thickness of the coatings was in the range from 20 to 24.7 μm. According to the data of X-ray phase analysis, the structure of the coatings is represented by a solid solution with a body-centered cubic (bcc) lattice and CuTi3, FeTi, Al65Cu20Fe15, and Ni35Al30Ti35 intermetallic compounds, and the proportion of intermetallic compounds increased with increasing pulse duration during ESD. Coatings were tested for oxidation resistance at a temperature of 900 °C and corrosion resistance by impedance spectroscopy and potentiodynamic polarization in a 3.5 % NaCl solution, as well as microhardness, friction coefficient and wear of coated samples with depending on the discharge pulses duration.