Document Type : Full Research Paper

Authors

• Vida Khalili ¹
• Jafar Khalil Allafi ²
• Hosein Maleki Ghaleh ³

¹ Ph.D Student, Research Center for Advanced Materials and Mineral Processing, Faculty of Materials Engineering, Sahand University of Technology

² Associate Professor, Research Center for Advanced Materials and Mineral Processing, Faculty of Materials Engineering

³ M.Sc, Research Center for Advanced Materials and Mineral Processing, Faculty of Materials Engineering

Abstract

NiTi shape memory alloy cannot provide all the clinical requirements of an implant due to the high nickel content and bio-inert surface.  Thus, its surface is coated by bio-ceramics such as hydroxyapatite (HA) in different methods in order to improve biocompatibility and bioactivity. In the present study, a bio-active coating of HA using electrophoretic deposition technique was created on the surface of NiTi alloy to act as a barrier and prevent the diffusion of nickel ions in to the body fluid. A suspension was prepared by n-butanol as solvent and triethylenamine as dispersant. Coatings were deposited at different voltage of 40, 60 and 80 V for duration of 120s on the cathode. Then coated samples were sintered at 800 °C under argon atmosphere for 2 hrs. Evaluation of coatings was performed by X-ray diffraction techniques (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). Bioactivity and corrosion behavior of HA coatings was studied within simulated body fluid (SBF) environment. The results showed, the sample coated at 60 V is dense, uniform, owing proper corrosion resistant, and also the ability for nucleation and growth of apatite layer in SBF.

Keywords

• NiTi shape memory
• electrophoretic
• Hydroxyapatite
• simulated body fluid