Ti 합금의 전기화학적 특성에 미치는 ZrN 코팅의 영향

Abstract

Electrochemical characteristics of Cp-Ti (G&S TITANIUM, Grade. 4, USA) and Ti-6Al-4V ELI (FORT WAYNE METAL, USA) coated with ZrN using RF-magnetron sputtering method were examined. The samples were cut and polished for corrosion test and coating. The specimens were coated with ZrN by RF-magnetron sputtering method. The microstructures were conducted by using optical microscope(OM), X-ray diffraction meter (XRD) and field emission scanning electron microscope (FE-SEM). The corrosion properties of the samples were examined through potentiodynamic test (- 700 mV∼+ 1000 mV) and A.C. impedance test (100 kHz ～ 10 mHz ) in 0.9% NaCl solution at 36.5 ± 1℃by PARSTAT (EG&G Co, 2273. USA). The results were as follows: 1. From the microstructure analysis, the Cp-Ti showed the acicular structure of α-phase and Ti-6Al-4V alloy showed the micro-acicular structure of α+β phase. 2. From the analysis of ZrN-coated layer analysis, the ZrN-coated surface showed columnar structure with 646 nm thickness. 3. The corrosion resistance of ZrN-coated Ti alloys were higher than those of the non-coated Ti alloys in 0.9% NaCl solution, indicating better protective effect. Corrosion resistance of coated Ti alloys increased in the order of ZrN coating. 5. From the analysis A.C. impedance analysis in 0.9% NaCl solution, the Rp value of ZrN-coated Ti alloys showed higher than those of Non-coated Ti alloy. Polarization resistance(Rp) values increased with ZrN coating.