Improved wear and corrosion resistance of TA15 alloy by SiC-reinforced and PDA/PTFE-sealed PEO coatings

In marine environments, factors such as saline exposure, high humidity, and mechanical wear can accelerate degradation and deteriorate the surface performance of titanium alloys. This study systematically investigated the effects of SiC particle incorporation into plasma electrolytic oxidation (PEO) coatings and the synergistic sealing treatment with polydopamine (PDA) and polytetrafluoroethylene (PTFE) on the corrosion and wear resistance of the titanium alloy coatings. Results demonstrated that the addition of SiC enhanced the hardness and wear resistance of the coating, but its effect on corrosion resistance was limited. The SiC-reinforced coating showed a reduced friction coefficient of 0.41, compared to 0.62 of the pristine coating. After PDA/PTFE sealing, the coefficient was further lowered to 0.18 and remained stable over prolonged sliding. Relative to the TA15 substrate, the SiC-PDA-PTFE coating exhibited a substantial reduction in wear rate, while the reduction relative to the 0SiC coating was about 76%. Combined with the strong interfacial adhesion promoted by PDA and the hydrophobic characteristics of PTFE, the SiC-PDA-PTFE coating exhibited reduced porosity and improved corrosion resistance. The integration of SiC reinforcement and PDA/PTFE sealing significantly enhanced the corrosion and wear resistance of the PEO coatings, providing a feasible strategy for titanium alloy surface protection under saline exposure and mechanical wear conditions.