Development of Ti-15Zr-15Mo-1Ag alloy for applications as biofunctional metallic implants

Abstract

Titanium (Ti) and its alloys have been employed mainly as biomaterials, in special as hard tissue replacements in dental and orthopedic fields. The combination of high mechanical strength, low density, good corrosion resistance, relative Young's modulus and recognized biocompatibility, result in better adaptation of Ti alloys with adjacent bone tissues (better than stainless steel 316L and Co-Cr alloys). Ti-6Al-4V alloy, developed by the aeronautic industry, is still extensively used as biomedical implants, besides its toxic potential promoted by Al and V ions releasing. Moreover, the development of novel biomedical materials has targeted low Young's modulus, in order to avoid stress shielding effect, with non-toxic composition. From our preliminarily results, we developed Ti-15Zr-15Mo alloy, which presented low Young's modulus, good mechanical properties, high tribocorrosion resistance and biocompatibility. Nowadays, the researches have sought in the development of biofunctional materials, with adding bioactive elements which induce bone regeneration and antibacterial effect. Silver (Ag) is a eutectoid ²-stabilizer element, recognized by its antibactericidal and strengthening effect in Ti alloys. Based on this, the project aims to study the effect of small amount of Ag (1 wt%) in the crystalline structure, microstructure, Vickers microhardness and Young's modulus of the Ti-15Zr-15Mo alloys, in order to add a potential antibactericidal effect in the composition. (AU)