Synthesis and characterization of high-voltage electrodeposited diamond-like carbon protective coating on TiAlV biomedical substrates † Ioan Viorel Branzoi, a Mihai Iordoc, b * Florina Branzoi, c Gimi Rimbu b * and Virgil Marinescu b Diamond-like carbon films (DLC) were deposited on TiAlV alloy substrates in liquid methanol by the liquid-phase electrodeposi- tion technique in nitrogen atmosphere at room temperature. The voltage applied between the electrodes was higher than 1800 V because of the use of resistive organic liquid. The electrochemical behavior of TiAlV and DLC-covered TiAlV samples was investigated in fetal bovine serum at 37  C and atmospheric pressure without agitation, using electrochemical impedance spectroscopy and potentiodynamic polarization as electrochemical techniques. For surface characterization techniques, we used scanning electron microscopy, X-ray diffraction, and Vickers microhardness measurements. Raman spectroscopy analysis of the films revealed three broad bands at approximately 1227, 1356, and 1550cm 1 related to possible diamond nanoparticles, to TiC or amorphous TiO x , and to D- and G-bands of DLC, respectively. The metallic ion release in bulk solution was studied by inductive coupling plasma–mass spectrometry. In uncoated samples, the release of metallic ions in bulk solution was much higher than in DLC-coated samples. Also, the corrosion resistance and Vickers microhardness of DLC-coated samples were improved in comparison with the uncoated samples. Copyright © 2012 John Wiley & Sons, Ltd. Keywords: diamond-like carbon; titanium alloy; corrosion behavior; electrodeposition; joint replacement Introduction Titanium and its alloys are extensively used in medical devices because of their properties such as good corrosion resistance and biocompatibility. However, because of the host body reactions such as inflammatory reactions and wear debris production in relative sliding, for instance on hip and knee joints, more resistant and advanced materials are required. In the last five decades, a lot of researchers have focused on the development of advanced biomaterials to supply the requirements of the human body. Diamond-like carbon (DLC) films have been a matter of intense re- search because of their interesting and well-suitable properties. [1–7] DLC is a metastable form of amorphous carbon containing a significant fraction of sp 3 bonds. [8] It can be widely used in biomedical applications because it imparts biocompatibility, chemical inertness, low friction coefficient, high hardness, and wear and corrosion resistance to a medical device’s surface. [9–16] More commonly, DLC films have been prepared by physical deposition techniques as physical vapor deposition, chemical vapor deposition, radio-frequency, ion beam deposition, and sputtering. Despite the high quality and growth rate of the films, sophisticated equipments with high vacuum systems and high temperatures (usually higher than room temperature) are required. The deposition of carbon film by using a liquid phase electrodeposition technique has attracted great interest in recent years [17] because this technique has demonstrated some obvious advantages in terms of simple setup, low temperature require- ments, and low cost. In a high electric field, organic molecules react on the surface of the electrode and form carbon and other products. The properties and the microstructure of the carbon films mainly depend on the preparation conditions, such as carbon source, deposition parameters, electrode substrates, and so on. The structure of the films is related not only to the carbon sources but also to the applied potential. High potential can improve the formation of sp 3 carbon. The deposition reaction of the carbon films in the liquid phase follows a polarization– reaction mechanism. Under high applied potentials, the polar carbon source molecules can be polarized into energized molecules, which move to and are absorbed on the surface of the electrode and become activated molecules. These activated molecules react and turn into carbon films. [18] The present work investigates the electrodeposition of DLC from methanol directly onto TiAlV substrates at room temperature, aiming to increase the wear resistance of this material without deteriorating its good corrosion resistance. * Correspondence to: Mihai Iordoc and Gimi Rimbu, National Institute for Re- search and Development in Electrical Engineering, INCDIE ICPE-Advanced Researches, 313 Splaiul Unirii, 030138 Bucharest, Romania. E-mails: mihai_ior- doc@icpe-ca.ro † Paper published as part of the ECASIA 2011 special issue. a Faculty of Chemistry, University Politehnica of Bucharest, Bucharest, Romania b National Institute for Research and Development in Electrical Engineering, INCDIE ICPE-Advanced Researches, 313 Splaiul Unirii, 030138 Bucharest, Romania c Institute of Physical Chemistry, Spl Independentei 202, Bucharest, Romania Surf. Interface Anal. (2012) Copyright © 2012 John Wiley & Sons, Ltd. ECASIA special issue paper Received: 5 September 2011 Revised: 20 December 2011 Accepted: 13 January 2012 Published online in Wiley Online Library (wileyonlinelibrary.com) DOI 10.1002/sia.4888