JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS 6 (2012) 89–94 Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/jmbbm Research paper Titanium and zirconium based alloys modified by intensive plastic deformation and nitrogen ion implantation for biocompatible implants A.V. Byeli a,∗ , V.A. Kukareko b , A.G. Kononov b a Physical-Technical Institute of the National Academy of Sciences of Belarus 10, Kuprevich street 220141 Minsk, Belarus b Joint Institute of Mechanical Engineering of the National Academy of Sciences of Belarus 12, Academicheskaya street 220072, Minsk, Belarus ARTICLE INFO Article history: Received 7 September 2009 Received in revised form 27 May 2011 Accepted 28 May 2011 Published online 1 December 2011 Keywords: Titanium Zirconium Equal channel angular pressing Ion implantation ABSTRACT Titanium and zirconium alloys are considered to be promising materials for orthopaedics because of their biocompatibility with tissues. Their main drawbacks for application as implants have generally been considered to be insufficient levels of mechanical and tribological properties. In this research the influence of equal channel angular pressing and nitrogen ion implantation on the structure and properties of Ti and Zr alloys has been investigated to ensure the optimum combination of the bulk material and surface layer properties. The data obtained showed that equal channel angular pressing and nitrogen ion implantation can be efficiently used to improve bulk and surface properties of Ti and Zr based implants. c ⃝ 2011 Elsevier Ltd. All rights reserved. 1. Introduction One of the most important problems in the development of new materials for medical applications is biocompatibility of materials with tissues (Niinomi, 2002). Titanium and zirconium based alloys are currently considered as the most promising biomaterials (Niinomi, 2002; Clarke et al., 2003; Balazic et al., 2007; Basso et al., 2008). These materials demonstrate a good combination of biocompatibility and corrosion resistance with low density and low module of elasticity (Niinomi, 2002). The main drawbacks of Ti and Zr based materials are comparatively low strength, wear and fatigue resistance. The development of high-strength, ∗ Corresponding author. Tel.: +375 17 284 18 22; fax: +375 17 284 18 22. E-mail address: byeli@presidium.bas-net.b (A.V. Byeli). wear and corrosion resistant biologically inert titanium and zirconium based alloys is a very prospective and important problem. In this research the technological processes of equal channel angular pressing (Segal et al., 2010) and high-current-density nitrogen ion implantation were used to ensure a high level of bulk and surface properties of the materials (Valiev et al., 2000; Nastasi and Mayer, 2006; Zhecheva et al., 2005; Shulov and Nochovnaya, 2002). The technology of equal channel angular pressing (ECAP) makes it possible to reach extremely high shear deformations in metals and alloys (Valiev et al., 2000; Segal et al., 2010; Valiev and Langdon, 2006). A promising technique of low-energy high-current-density nitrogen ion implantation 1751-6161/$ - see front matter c ⃝ 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jmbbm.2011.05.034