Characteristics, apatite-forming ability and corrosion resistance of NiTi surface modified by AC anodization

Comparison of corrosion resistance and apatite-forming ability of NiTi treated by different low-temperature methods

“…R a increased after treatment, being highest for samples treated by AC anodization. The high R a for AC-NiTi could be attributed to the presence of hydroxyapatite (HA) particles on the surface [20] (see also XRD patterns in Fig. 6).…”

“…Though the treatment temperature is low (<200 • C), crystallization to anatase was possible because of the catalytic effect of water [25,26]. All the processes were capable of reducing the surface Ni content, either because of the preferential oxidation of Ti [16,[18][19][20], or of the Ti oxide deposited onto the substrate [17,21]. The EIS data acquired at open-circuit potential in Hanks' solution are shown in the Nyquist plots in Fig.…”

“…This means that low-temperature methods are preferable in the surface treatment of NiTi as they would not disrupt the properties already built in by previous thermomechanical treatment. In view of this consideration, a number of simple low-temperature processes to improve the corrosion resistance of NiTi implants by TiO 2 coating have been attempted by the authors recently [16][17][18][19][20][21]. In this short communication, these methods are described, the characteristics of the oxide coatings are summarized, and the improvements in corrosion resistance in Hanks' solution (a simulated body fluid) are compared and discussed.…”

The corrosion resistance behavior of Al2O3 coating prepared on NiTi alloy by micro-arc oxidation

“…In order to improve the corrosion resistance of the NiTi alloy and suppress the release of Ni ion, many surface modification techniques have been employed in previous literature, including thermal oxidation [4], laser surface treatment [5], sol-gel method [6] and anodiztion [7][8][9]. Each of the techniques has its own merits and limitations.…”

Martensitic transformation in NiTiCo strip covered by nanocrystalline platinum layer

“…NiTi-based shape memory alloys (SMA) have been well known from their practical application, especially, in egative influence is reported [3,4]. Considering the high nickel content in NiTi alloy, a great attention has been paid to the dissolution of nickel from the base material due to corrosion.…”