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Effect of TiO 2 –Ti and TiO 2 –TiN composite coatings on corrosion behavior of NiTi alloy
Author(s) -
MalekiGhaleh H.,
KhalilAllafi J.,
Aghaie E.,
Siadati M. H.
Publication year - 2015
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.5679
Subject(s) - materials science , nickel titanium , corrosion , dielectric spectroscopy , scanning electron microscope , metallurgy , coating , titanium , composite number , oxide , alloy , titanium alloy , titanium nitride , tin , composite material , electrochemistry , nitride , shape memory alloy , electrode , layer (electronics) , chemistry
Two kinds of biocompatible coatings were produced in order to improve the corrosion resistance of nickel titanium (NiTi) alloy. A titanium oxide–titanium (TiO 2 –Ti) composite was coated on NiTi alloy using electrophoretic method. After the coating process, the samples were heat‐treated at 1000 °C in two tube furnaces, the first one in argon atmosphere and the second one in nitrogen atmosphere at 1000 °C. The morphology and phase analysis of coatings were investigated using scanning electron microscopy and X‐ray diffraction analysis, respectively. The electrochemical behavior of the NiTi and coated samples was examined using polarization and electrochemical impedance spectroscopy tests. Electrochemical tests in simulated body fluid demonstrated a considerable increase in corrosion resistance of composite‐coated NiTi specimens compared to the non‐coated one. The heat‐treated composite coating sample in nitrogen atmosphere had a higher level of corrosion resistance compared to the heat‐treated sample in argon atmosphere, which is mainly due to having nitride phases. Copyright © 2014 John Wiley & Sons, Ltd.