Surface Modification Techniques for Biomedical Grade of Titanium Alloys: Oxidation, Carburization and Ion Implantation Processes

Titanium and titanium alloys are widely used in a variety of engineering applications, where the combination of mechanical and chemical properties is of crucial importance. Aerospace, chemical and automotive industries as well as the medical device manufacturers also benefited from the outstanding properties of titanium alloys. The wide spread of its uses in biomedical implants is mainly due to their well-established corrosion resistance and biocompatibility. However, not all titanium and its alloys can meet all of the clinical requirements for biomedical implants. For instance, it is reported that bare titaniumvanadium alloy has traces of vanadium ion release after long period exposure with body fluid (Lopez et al., 2010). Excessive metal ions release into the body fluid and causes toxicity problems to the host body. A new group of titanium alloy such as Ti-Nb and Ti-Zr based are recently introduced in the market to overcome the toxicity of titanium-vanadium based alloy (Gutierrez et al., 2008). Although, these alloys have a high strength to weight ratio and good corrosion resistance and biocompatible, but it suffers from poor tribological properties which limits their usefulness to a certain extent especially when they are applied to joint movements. Wear debris generated from these articulation joints can induce inflammation problem and toxic effect to the human body. In biomedical point of view, post implantation is very crucial stage where the interaction between the implanted material surface and the biological environment in human body is critically evaluated. Either in the short or long run, the toxic effect becomes an issue to host body. Hence, the implant material surface has a strong role in the responses to the biological environment. In order to improve the biological and tribological properties of implant materials, surface modification is often required (Huang et al., 2006, Kumar et al., 2010b). This chapter embarks on the commonly used implant biomaterials, followed by general overview on the surface modification techniques for treating titanium alloy. The basic principles of oxidation, carburization and ion implantation methods and their developments are discussed in the following sections.