Performances Investigation of Ti6Al4V Alloy Modified by Plasma Nitriding + Plasma Enhanced Chemical Vapor Deposition and Laser Remelting Process in Simulated Body Fluid

Abstract

To enhance the corrosion and wear resistance of biological titanium alloy Ti6Al4V in the human body, plasma nitriding + plasma enhanced chemical vapor deposition (PN + PECVD), laser remelting (LR) process were employed to modify the titanium alloy, respectively. The microhardness of LR and PN + PECVD samples was reported to increase by 117% and 165%, respectively, in contrast to that before the samples were modified. The thickness of LR modified layer was reported as 10 μm, and the nitrided film on the surface of PN + PECVD sample exhibited the thickness of 2 μm. The wear and corrosion performances of three samples were analyzed by friction and corrosion experiments in the simulated body fluid. As revealed from the experimental results, the wear rates of LR and PN + PECVD samples were 74.1% and 94.5% lower than that of Ti6Al4V. It can be seen that the surface modification layer can play a good role in protecting Ti6Al4V substrate from wear. By the electrochemical corrosion experiment, the corrosion resistance of Ti6Al4V, LR and PN + PECVD samples was ranked as PN + PECVD > LR > Ti6Al4V. It is therefore speculated that the PN + PECVD and LR modification processes could noticeably enhance the corrosion and wear resistance of Ti6Al4V in the human body.