Study On Wearing And Corrosion Resistance Of Ti-6Al-4V And TAMZ Alloy Implanted By Carbon Ions In Hank’s Simulated Body Fluid

Biomedical metals are used widely on clinic. Owing to excellent corrosion and mechanical resistance, biocompatibility, particular shape memory effect and biologic mechanical properties, titanium alloys have attracted much interest of researchers. However, when being implanted into body, metals would be corroded inevitably resulting from the influence of body fluid. At the same time, as the medical prosthesis metal will lead to friction and wear in the body. Friction and corrosion synergy to the loss of more serious material, shorten its life. So, the research of medical metal corrosion and friction behavior is very important.In this article, electrochemical techniques was applied to investigate the general corrosion behavior and friction behavior of carburization and no-carburization Ti-6Al-4V and TAMZ samples immersed in the Hank’s solution. The results were as followed:1. After the carburization, a disordered film formed on the titanium surface. After the XRD analysis, we know that it is made up of TiC,Ti and a little TiO2. As the carbide is hard phase, dispersed in the alloy surface, make injection layer show swelling stress, improve the surface hardness and Friction resistance of the alloy. At the same time, the disordered carbide film formation blocks the dissolution of alloying elements and enhances metal corrosion resistance.2. The polarization curves results in the Hank’s solution show that the worn sample’s current density is larger than no-worn sample’s. Show the environment under the conditions of wear and corrosion are more likely to be more demanding. The I-t curves results show that the carburized sample’s current density is larger than untreated sample’s, and the alloy is more stable after carburizing treatment, When under the same potential, if the temperature is higher, then the current density is also larger.3. In this study, they all can be expressed in the form of i0=k·t-1/2+a, and verifies under the experimental conditions, the development of pitting corrosion is controlled by dissolution rate of surface film. At the same time, the apparent activation energy expression for two titanium alloys is:lgI=lgk0-(Ea)/(2.303RT).The apparent activation energy of the carburized and no-carburized Ti-6Al-4V alloy are22.89kJ/mol and19.63kJ/mol, after friction are19.61kJ/mol and19.29kJ/mol; TAMZ alloy’s are40.46kJ/mol and29.53kJ/mol, after friction are25.64kJ/mol and20.99kJ/mol.4. Two titanium micro electrochemical scanning tests, cyclic voltammetry showed that the ion implantationcan significantly improve the corrosion resistance of the two alloys, and after a period of time, the maximum peak current change is very small, with constant potential with the experimental result.5. After the carburization, under the same load, the friction coefficient of the two alloys is lower than the no-carburized sample, the wear quality reduces and the hardness increases.