A.C. Impedance Properties of HA/Ti Compound Layer coated Ti-30Ta-(3~15)Nb Alloys
Ti-30Ta-(3~15)Nb 합금에 HA/Ti 복합 코팅한 표면의 교류임피던스 특성
정용훈;이호종;문영필;박근형;장승현;손미경;최한철;
Jeong, Y.H.;Lee, H.J.;Moong, Y.P;Park, G.H.;Jang, S.H.;Son, M.K.;Choe, H.C.;
조선대학교 치과대학 생체재료학교실 및 생체재료나노계면활성화센터, 2단계 BK21;순천대학교 공과대학 미래전략신소재공학;
Department of Dental Materials & Research Center of Nano-Interface Activation for Biomaterials, College of Dentistry, 2nd Stage of Brain Korea 21 for College of Dentistry;Department of Materials Science & Metallurgical Engineering, Suchon National University;
DOI : 10.5695/JKISE.2008.41.5.181
A.C. impedance properties of HA/Ti compound layer coated Ti-30Ta-($3{sim}15$)Nb alloys have been studied by electrochemical method. Ti-30Ta binary alloys contained 3, 7, 10 and 15 wt% Nb were manufactured by the vacuum furnace system. And then specimen was homogenized at $1000^{circ}C$ for 24 hrs. The sample was cut and polished for corrosion test and coating. It was coated with HA/Ti compound layer by magnetron sputter. The non-coated and coated morphology of Ti alloy were analyzed by X-ray diffractometer (XRD), energy X-ray dispersive spectroscopy (EDX) and filed emission scanning electron microscope (FE-SEM). The corrosion behaviors were investigated using A.C. impedance test (PARSTAT 2273, USA) in 0.9% NaCl solution at $36.5{pm}1^{circ}C$. Ti-30Ta-($3{sim}15;wt%$)Nb alloys showed the ${alpha}+{eta}$ phase, and $eta$ phase peak was predominantly appeared in the case of increasingly Nb contents. The microstructures of Ti alloy were transformed from needle-like structure to equiaxed structure as Nb content increased. From the analysis of coating surface, HA/Ti composite surface uniformed coating layer with 750 nm thickness. The growth directions of film were (211), (112), (300) and (202) for HA/Ti composite coating on the surface after heat treatment at $550^{circ}C$, whereas, the growth direction of film was (110) for Ti coating. The polarization resistance ($R_p$) of HA/Ti composite coated Ti-alloys were higher than those of the Ti and HA coated samples in 0.9% NaCl solution at $36.5{pm}1^{circ}C$. Especially, corrosion resistance of Ti-Ta-Nb system increased as Nb content increased.
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