A review on biomedical implant materials and the effect of friction stir based techniques on their mechanical and tribological properties

Various biomedical implants for prolonged usage in the human body have been created in recent years in a massive and steadily increasing number. Friction stir techniques are solid-state procedures used to improve the grain structure of biomaterials or to connect two workpieces while retaining their essential physical characteristics. This article primarily discusses the multidisciplinary topic of biocompatible implant surfaces from a microstructural, tribological, and mechanical strength perspective. It provides an overview of the most frequently used biomaterials, including metals such as steel, magnesium, and titanium, as well as polymers such as polyethylyne and polyether ether ketone (PEEK), their bulk and surface properties based on structural properties, and surface modification using various friction stir based techniques. These methods have the potential to substantially increase the lifespan of implants and their presence in human bodies.