On the Corrosion Behaviour of Low Modulus Titanium Alloys for Medical Implant Applications: A Review

Abstract

The corrosion behaviour of new generation titanium alloys (β-type with low modulus) for medical implant applications is of paramount importance due to their possible detrimental effects in the human body such as release of toxic metal ions and corrosion products. In spite of remarkable advances in improving the mechanical properties and reducing the elastic modulus, limited studies have been done on the electrochemical corrosion behaviour of various types of low modulus titanium alloys including the effect of different beta-stabilizer alloying elements. This development should aim for a good balance between mechanical properties, design features, metallurgical aspects and, importantly, corrosion resistance. In this article, we review several significant factors that can influence the corrosion resistance of new-generation titanium alloys such as fabrication process, body electrolyte properties, mechanical treatments, alloying composition, surface passive layer, and constituent phases. The essential factors and their critical features are discussed. The impact of various amounts of α and β phases in the microstructure, their interactions, and their dissolution rates on the surface passive layer and bulk corrosion behaviour are reviewed and discussed in detail. In addition, the importance of different corrosion types for various medical implant applications is addressed in order to specify the significance of every corrosion phenomenon in medical implants.

Beneficial Effects of Vanadium Additions on the Corrosion of Ti6AlxV Alloys in Chloride Solutions

“…Numerous titanium base alloys have been successfully employed in the area of biomedical applications [9,[11][12][13][14][15][16][17]22,23]. A great number of these Ti-base alloys are being used as artificial joints of hips and knees, screws for fracture fixation, and bone plates to replace flawed parts in human bodies.…”

Manufacturing of Ti-6%Al and Ti-6%Al-4%V Alloys and Their Corrosion in Sodium Chloride Solutions

“…Numerous titanium base alloys have been reported to have a vital usage in the field of biomedical applications [12][13][14][15][16][17][18][19][20][21]. These alloys have been employed as screws for fracture fixation, artificial hip and knee joints, and bone plates to replace the failed tissues in the human bodies.…”

Failure Analysis of Biometals

“…The Special Issue "Failure Analysis of Biometals" comprises ten original research articles [1][2][3][4][5][6][7][8][9][10] covering a great common range of metallic biomaterials (Ti alloys, CoCrMo alloys, Mg alloys, NiTi alloys) and their failure mechanisms (corrosion, fatigue, fracture, and fretting wear) that commonly occur in medical implants and surgical instruments. This collection of studies also includes two review papers [9,10]: the corrosion behaviour of new generation low modulus titanium alloys for implant applications, and the three-dimensional (3D) printed acetabular cups for hip replacement implants reviewing the clinical use of 3D printing in orthopaedics.…”

“…Finally, this Special Issue presents a review article [10] on the corrosion behaviour of new generation titanium alloys (β-type offering low Young's modulus) that can be desirably used for medical implants.…”

“…Although there has been a lot of work around the improvement of mechanical properties in these alloys, their corrosion behaviour still needs further research (given that the implant working environment is corrosive). In this article, Afzali et al [10] reviewed and discussed a number of key factors (fabrication process, chemical composition, passive layer, mechanical treatments, body electrolyte properties, and constituent phases) influencing the corrosion behaviour/resistance of new generation titanium alloys. The effects of α and β phases and their dissolution rates on the oxide layer and corrosion behaviour were also reviewed.…”