양극산화된 임플란트용 합금의 전기화학적 거동에 미치는 TiN 코팅의 역할

Abstract

Cp-Ti of 99.5 % purity (grade 4) and Ti-6Al-4V ELI were used as a substrate material for anodic oxidation. Titanium were anodized in solution containing typically 1 M H3PO4 at room temperature. A direct current power source was used for the process of anodization. Anodized titanium was prepared using 120～220 V anodization voltage at room temperature. The TiN coatings were produced by RF magnetron sputtering on anodized layer, using target of Ti (99.99%). Coated layers microstructure, chemical composition, crystal structure and corrosion properties were determined using SEM, XRD and electrochemical equipments. The corrosion behavior was measured using electrochemical impedance spectroscopy (1000 KHz ～ 10 mHz: M-1025, Potentiostat, Model 263, EG&G, USA) and potentiodynamic(-1500 mV ~ +2000 mV) test at 0.9 % NaCl solution. The results were as follows: 1. From the micro structure analysis, Cp-Ti shows the acicular structure of α-phase and Ti-6Al-4V shows the needle-like structure of α+β phase. 2. From the surface properties of anodic layer, input voltages increased with increased pore size and numbers. But the corrosion resistance of input 180 V anodic layer were higher than another conditions. 3. From the analysis of TiN coated layer analysis, TIN coated surface showed columnar structure with 610nm thickness, respectively. 4. The corrosion resistance of anodized, TiN and anoidzed/TiN duplex coated Ti alloys were higher than those of the non-coated Ti alloys in 0.9% NaCl solution from potentiodynamic test, indicating better protective effect. 5. From the A.C. impedance analysis in 0.9% NaCl solution, Rp values of anoidized/TiN duplex coated Ti alloys showed 7.922×10^(6) Ω㎠ and 9.992×10^(6) Ω㎠, respectively. Anodized/TiN duplex coated Ti alloy were higher than those of non-coated Ti alloy, anoidzed and TiN coated.