Corrosion behavior of metallic materials in biomedical applications. I. Ti and its alloys

The use of metallic materials for implantable medical devices has prompted numerous studies aimed at characterizing the corrosion susceptibility of these materials and understanding their electrochemical behavior in simulated and actual physiological liquids. This review focuses on the forms of corrosion that are of principal interest for Ti and its alloys in vivo : general corrosion, pitting corrosion, crevice corrosion, galvanic corrosion, and fretting corrosion. It also addresses environmentally assisted cracking in the form of hydrogen embrittlement. Of particular interest is the susceptibility of Ti and its alloys to the different forms of corrosion with regard to both solution chemistry, especially the effect of organic species, and surface characteristics such as oxide composition, surface inclusions, and wear/fretting.