Tribological Studies on Titanium Alloys for Biomedical Applications

Abstract

Titanium alloys are widely used in different industrial sectors such as aerospace, automotive, biomedical, chemical, etc. due to its attractive properties. These involve low density, enhanced corrosion resistance, low elastic modulus, high strength-to-weight ratio, biocompatibility, etc. In biomedical field, titanium alloys such as Ti6Al4V, Ti-5Al-2Nb-1Ta, Ti-15Mo, gamma Ti-Al, Ti-6Al-7Nb, Ti-5Al-2.5Fe, etc. are commonly used as orthopaedic and dental implants. However, these alloys exhibit poor tribological properties. Increased adhesive and fretting wear, fretting fatigue, low resistance to abrasion, high frictional coefficients, etc. are the common phenomena observed during their functioning which result in poor tribological behaviours. Wear resistance of such alloys can be enhanced by using various surface treatment techniques such as physical vapour deposition coatings, plasma nitriding, plasma electrolytic oxidation, plasma immersion ion implantation, surface texturing through laser, thermal oxidation, etc. Use of different lubricants has also been proven to be effective in reducing wear rate among alloys. This chapter highlights different studies carried out by researchers on the tribological behaviour of titanium alloys used for biomedical purposes. Results of surface treatment and lubrication on tribological behaviour of titanium alloys are highlighted. Effects of different process parameters such as sliding distance, sliding speed and normal load on wear behaviour of alloys are discussed in detail. Different wear mechanisms occurring during sliding motion are also elucidated in this chapter. The chapter can serve as a directory while selecting titanium alloys for different biomedical applications.