Effect of surface finishing on the formation of nanostructure and corrosion behavior of Ni–Ti alloy

Abstract

In the present work, we have investigated the formation of nanostructured oxide layers by anodic oxidation on different surface finished (mirror finished, 600 and 400 grit polished) nickel–titanium alloy (Ni–Ti) in electrolyte solution containing ethylene glycol and NH4F. The anodized surface has been characterized by field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and X‐ray photoelectron spectroscopy (XPS). The corrosion behaviors of the Ni–Ti substrate and anodized samples have been investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization in simulated body fluid (Hanks' solution). The results show that the native oxide on the substrate is replaced by nanostructures through anodization process. XPS of Ni–Ti substrate shows the presence of Ni0, NiO, Ti0 and TiO2 species, whereas Ni2O3 and Ni(OH)2 and TiO2 are observed in the samples after anodization. Corrosion resistance of the anodized sample is comparable with that of the untreated sample. Copyright © 2016 John Wiley & Sons, Ltd.

Carbon plasma immersion ion implantation and DLC deposition on Ni−Ti alloy

“…Details of XPS experiments are described elsewhere. [12,13] Electrochemical studies were performed in 200 ml of SBF on untreated NiÀ Ti and PIII-C + DLC-coated samples at 37 � 2 °C. A conventional three-electrode cell consisting of saturated calomel electrode (SCE), Pt, and NiÀ Ti as reference, counter, and working electrodes, respectively, was used to conduct the electrochemical studies using CH 604 D electrochemical workstation.…”

“…[6,7] In this sense, it is necessary to develop a barrier layer for impeding the out diffusion of Ni ions from implants. There are numerous techniques that have been used to modify the NiÀ Ti alloy surface such as heat treatment, [8,9] sol-gel deposition, [10] electrochemical process, [11][12][13] etc. Plasma immersion ion implantation (PIII) technique is well-known and widely used method for surface modification of NiÀ Ti alloy and also irregular shaped substrates.…”

Fabrication of TiO2 microspikes for highly efficient intracellular delivery by pulse laser-assisted photoporation

“…The electrochemical formation of porous/micro/nanostructures for different types of materials such as Al, 9 Fe, 10 Hf, 11 Mg, 12 Nb, 13 Ni, 14 Ru, 15 Si, 16 W, 17 and Ti [18][19][20] already exists. Besides the metal substrate, nanostructures can also be formed using anodization on Ti alloy substrates, such as Ti-6Al-7Nb, 8,21 Ni-Ti, 22,23 Ti-6Al-4V, 7 Ti13Nb13Zr 24, 25 and Ti15Mo. 26 Among the many nanostructured oxide materials, TiO 2 -based nanostructures have signicant characteristics, such as improved ion-exchangeable ability, photocatalytic properties, environmental safety, and nontoxicity.…”

On the Electropolishing Mechanism of Nickel Titanium in Methanolic Sulfuric acid − An Electrochemical Impedance Study

“…Thus, brightening or micromachining of NiTi becomes very important to be investigated . Another positive side effect of electropolishing resulting from the smooth and defect free surface is the reduction of susceptibility against corrosion …”