Abstract
Nickel ion release from NiTi shape memory alloy is an issue for biomedical applications. This study was planned to study the effect of C+ implantation on nickel ion release and affinity of calcium phosphate precipitation on NiTi alloy. Four annealed samples are chosen for the present study; three samples with oxidation layer and the fourth without oxidation layer. X-ray diffraction (XRD) spectra reveal amorphization with ion implantation. Proton-induced X-ray emission (PIXE) result shows insignificant increase in Ni release in simulated body fluid (SBF) and calcium phosphate precipitation up to 8 x 10(13) ions/cm(2). Then Nickel contents show a sharp increase for greater ion doses. Corrosion potential decreases by increasing the dose but all the samples passivate after the same interval of time and at the same level of VSCE in ringer lactate solution. Hardness of samples initially increases at greater rate (up to 8 x 10(13) ions/cm(2)) and then increases with lesser rate. It is found that 8 x 10(13) ions/cm(2) (approximate to 10(14)) is a safer limit of implantation on NiTi alloy, this limit gives us lesser ion release, better hardness and reasonable hydroxyapatite incubation affinity.