Surface modification of Ti6Al4V surgical alloy by plasma source ion implantation

Abstract

Plasma source ion implantation (PSII) was applied to Ti6Al4V surgical alloy to improve its tribological properties. Nitrogen implantation at room temperature produced an improvement in wear resistance. Implantation at an elevated temperature (approximately 600 °C) resulted in a substantially thicker modified surface layer with sustained wear resistance. The best results were obtained by a two-step process wherein elevated temperature implantation was followed by room temperature implantation. The tribological properties resulting from this two-step process surpassed those of the CoCr alloy and were comparable with those obtained by ion nitriding. The base material properties remained unchanged after the PSII treatments. The surface properties were characterized using low-road microhardness measurements, pin-on-disk wear testing and Auger spectroscopy.