Study On Processing And Surface Properties Of Double Glow Plasma Niobizing And Oxygenizing On Medical Titanium

Pure titanium and titanium alloy because of its excellent biocompatibility, corrosion resistance, mechanical properties and processing performance, becoming the most widely used biomedical metallic materials, which is mainly used for artificial joints, dental, plastic surgery, cardiac surgery, the body supporting frames and other medical fields. Titanium has good corrosion resistance, but in dilute HCl, H2SO4 and other non-oxidizing acid solution, there is uniform corrosion and crevice corrosion and so on.. In a complex physiological environment of the human body, titanium can also be easily eroded by body fluids. As a material implanted in the body, good resistance and blood compatibility is needed, because the biological materials and some of the major human blood contact on the surface of the material, so to improve corrosion resistance, wear resistance and blood compatibility of the materials is the key design and synthesis of the material surface.To solve the above problems, this paper proposed to form Ti-Nb and Ti02 surface-modification layers on pure titanium by using the double glow plasma surface alloying technique, The microstructure of the surface modified layers are analyzed by means of OM, EDS, XRD and SEM respectively, and tested its surface corrosion resistance, wear resistance and blood compatibility.After plasma niobizing and oxygenizng, modification of uniform dense layer is formed on titanium-based surface, Nb layer Ti-Nb intermetallic compounds is the major phase of niobizing layer. oxygenizng layer was mainly builded up with Ti02. In both simulated artificial body fluids, compared with the titanium substrate, niobizing and oxygenizng layer have higher corrosion potential, smaller corrosion current density and corrosion rate, so the corrosion resistance is improved. The friction coefficients of niobizing layer and oxygenizng layer are reduced from 0.57 to 0.27, 0.45. And the alloyed layer exhibit lower wear scar depth and wear scar width, indicating a good wear resistance.The wear volumes of both niobized layer and oxygenizng alloying layer decrease drastically compared to the matrix. In the dynamic clotting time, hemolytic rate and roughness tests, the modified layer also showed good blood compatibility.