Application of bulk nanostructured materials in medicine

Titanium alloys have been the mostly used materials of choice for medical implants. They are generally considered chemically inert, biocompatible with human tissue and resistant to corrosion by human body fluids. However the small percentages of vanadium and aluminium atoms (main alloying elements) contained in the alloy are potentially toxic. Normal wear call lead to deterioration of the implant and the release of alloying elements into the body. The novel process-a combination of severe plastic deformation with traditional metal forming process-can produce special material structure with nanosize grains. This nanostructured material has high tensile and fatique strength and even the enhanced ductility. Pure titanium is chemically and biologically more compatible with human fluids and tissue than other materials but the coarse-grained titanium is too weak for prostheses that Must bear heavy loads Such as leg or hipbone implants. The strength of pure titanium is less than half the strength of Ti-6Al-4V alloy what is mostly have used for medical implants. By using the mentioned novel process the strength of pure titanium with nanosize grains can be increased even higher than in case of the conventional Ti-6Al-4V alloy. This new process creates medical implants that are strong enough to bear heavy loads without failure. The implant material is corrosion resistant and biocompatible with human body organs and fluids so it can remain in the body for years. (c) 2005 Elsevier B.V. All rights reserved.