Preparation and Wear Resistance of CNT‐Doped PEO Coating on the TC4 Alloy

Titanium alloy had the characteristics of high specific strength, low density, and good mechanical properties and biocompatibility, so it was a promising material for human body implantation. However, the wear resistance of titanium alloy was poor, which greatly limited its application. The ceramic coating was synthesized on the surface of titanium alloy by surface modification technology to improve its wear resistance. In this research, ceramic coatings doped with carbon nanotubes (CNTs) were successfully synthesized on the surface of Ti6Al4V (TC4) titanium alloy by plasma electrolytic oxidation (PEO) technique. The phase composition, surface morphology, crystal structure, and roughness of PEO coating were determined by XRD, FESEM, Raman spectroscopy, and laser confocal microscope. The hardness of PEO coating was measured by a microhardness tester, and the sliding wear test of PEO coating was carried out. The effects of CNT doping on the structure and tribological properties of PEO coating were discussed. The results showed that CNTs successfully participated in the formation process of the PEO coating and some micropores were closed and eliminated, and then, it reduced the surface roughness. The thickness of PEO coating reduced, but the density improved. CNT doping significantly improved the wear resistance of PEO coating and friction coefficient decreased by 43.14%. The corrosion resistance of PEO coatings doped with appropriate CNTs improved.