Surface Modification Methods for Titanium and Its Alloys and Their Corrosion Behavior in Biological Environment: A Review

Abstract

Titanium (Ti) and its alloys are being used in biomedical field owing to their low elastic modulus, good fatigue strength and formability, and corrosion resistance. However, they are still not sufficient for long-term clinical usage as they are bio-inert and they cannot bond to living bone directly at the early stage after implantation into a human body. Their surfaces play an important role in response to the artificial devices in a biological environment; for these materials to meet the clinical demands, it is necessary to modify their surface. The corrosion resistance and biological properties of Ti and its alloys can be improved selectively by using the appropriate surface modification techniques while the desirable bulk attributes of the materials are retained. The proper surface treatment expands the use of these materials in the biomedical field. This article reviews the various surface modification techniques for Ti and its alloys including mechanical methods, chemical and electrochemical treatment, thermal spraying, sol–gel, and ion implantation towards the field of biomedical engineering. A positive effect of various surface modification techniques is illustrated in this review as suggested by many research groups. Also, this article includes the corrosion behavior of surface-modified Ti and its alloys for biomedical applications.