| Abstract |
| Corrosion behaviors of TiN coated dental casting alloys have been researched by using various electrochemical methods. Three casting alloys (Alloy 1: 63Co-27Cr-5.5Mo, Alloy 2: 63Ni-16Cr-5Mo, Alloy 3: 63Co-30Cr-5Mo) were prepared for fabricating partial denture frameworks with various casting methods; centrifugal casting(CF), high frequency induction casting(HFI) and vacuum pressure casting(VP). The specimens were coated with TiN film by RF-magnetron sputtering method. The corrosion behaviors were investigated using potentiostat (EG&G Co, 263A. USA) in 0.9% NaCl solution at 36.5±1℃. The corrosion morphologies were analyzed using FE-SEM and EDX. Alloy 1 and Alloy 2 showed the α-Co and ε-Co phase on the matrix, and it was disappeared in case of TiN coated Alloy 1 and 2. In the Alloy 3, Ni2Cr second phases were appeared at matrix. Corrosion potentials of TiN coated alloy were higher than that of non-coated alloy, but current density at passive region of TiN coated alloy was lower than that of non-coated alloy. Pitting corrosion resistances were increased in the order of centrifugal casting, high frequency induction casting and vacuum pressure casting method from cyclic potentiodynamic polarization test. |
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| Key Words |
| TiN coating, casting alloy, pitting corrosion, Ni2Cr phase, α-Co and ε-Co phase |
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