Improvements in the Hardness of Surgical Titanium Alloys by Ion Implantation

Abstract

ABSTRACTTitanium is generally recognized as one of the most biocompatible metal species, and as such, titanium based alloys are among the top contenders for the material of choice in orthopaedic prostheses. The questionable wear performance of titanium in abrasive and adhesive wearing conditions has been an impediment for a more widespread use of the alloy up to now. The ion implantation process has been shown to be extremely effective, in laboratory experiments, in enhancing the wear performance of the metal and at the same time reducing the wear of ultra high molecular weight polyethylene (UHMWPE) mating surface in contact with the alloy.The present paper focuses on the increased hardness of the Ti-6Al-4V alloy as a result of ion implantation. It is generally believed that the wear improvements of titanium as a result of ion implantation are directly proportional to increased hardness of the surface. Thus, hardness data can be useful for the screening of ion implantation parameters to identify the optimum processing conditions. The Knoop hardness of ion implanted Ti-6Al-4V samples has been measured for B, C, N, N2, O and Ne ion species.