International Refereed Journal of Engineering and Science (IRJES) ISSN (Online) 2319-183X, (Print) 2319-1821 Volume 1, Issue 4(December 2012), PP.42-47 www.irjes.com www.irjes.com 42 | Page Corrosion study of ZrN coated Ti6Al4V alloy in Normal Saline (0.9% NaCl) Solution Suresh N. Kadam 1 , Kailash R. Jagdeo 2 , M. R. Nair 3 1. Dept. of Physics, KET’s V. G. Vaze College, Mumbai(MS), India. 2. Dept. of Physics, DSPM’s K. V. Pendharkar College, Dombivli(MS), India. 3. Principal, Model College, Dombivli(MS), India. ABSTRACT: Titanium and Ti6Al4V alloy are widely used as biomaterial for implants. However, leaching out of V and Al in a physiological environment constitute the main limitation for their applications. Zirconium nitride (ZrN) coating started to attract more attention for its excellent corrosion resistance and biocompatibility which exhibits suitable properties for great varieties of industrial applications. Here, electrochemical corrosion behaviour in normal saline solution of ZrN coated Ti6Al4V alloy, coated by cathodic arc physical vapour deposition with parameters; substrate bias voltages of -50V, -200V, -350V and -500V; nitrogen gas pressure 10 mtorr; duration of coating 20 minutes is studied. ICPAES was used to determine amount of Al leached out when immersed in normal saline solution. The crystallographic orientation and surface morphology was studied using X-ray diffraction and Scanning Electron Microscope (SEM/EDAX). Microhardness was carried out using Vickers method by applying 10g load. ZrN coating improves corrosion resistance, microhardness and elemental out-diffusion resistance. Keywords: biomaterials; cathodic arc PVD; electrochemical corrosion; microhardness. I. INTRODUCTION Ti6Al4V alloy has been used extensively in biomedical applications such as hip replacements and dental implants due to its attractive combinations of mechanical properties, corrosion resistance and biocompatibility [1-5]. However, despite of its favorable mechanical properties, physicians still have concern against this alloy because of leaching out of Al and V from the surface of implants and their allergic reaction, toxicity and carcinogenicity. Aluminum is well known as to cause certain bone diseases and neurological disorders. For these reasons there are a lot of studies and attempts are made, in one hand to improve tribological and corrosion properties and in other hand to improve biocompatibility of the material. In order to improve corrosion resistance, various surface modification technique are used. The physical vapour deposition (PVD) coating is widely used in biomedical materials in current decade because of this good tribological and an anti- corrosion performance is achievable [6-13]. Zirconium nitride (ZrN) coating started to attract more attention for its excellent corrosion resistance and biocompatibility. It has been reported that ZrN coating showed higher corrosion resistance compared to that of TiN coating [14, 15]. Stoichiometry of ZrN is the only stable phase with a gold-like colour due to its metallic band structure. This coating appears to have substantial potential in aero engine, industrial and biological application [16]. In the present study, ZrN is selected for coating on Ti6Al4V alloy using cathodic arc physical vapour deposition in order to improve corrosion performance and the surface properties. II. EXPERIMENTAL 2.1 Sample preparation Table1 Chemical composition ( wt. %) of Ti6Al4V C Ni Mn Mo V Ti N Sn Fe Al 0.036 0.001 0.008 0.004 4.08 89.56 0.008 0.011 0.25 5.97