Two novel Ti–Mo–Ta–Zr alloys for medical devices: Their microstructure, corrosion resistance and microhardness characteristics

Abstract

Titanium alloys have gained a solid reputation in the field of biomedicine due to their exceptional biocompatibility. However, it is important to note that some of these alloys do release toxic ions, which could potentially limit their application in sensitive scenarios. This study examines two new titanium alloys, TixMo15Ta7Zr (x = 15, 20 wt%) and it designed these alloys to overcome certain challenges by including helpful elements like molybdenum (Mo), tantalum (Ta) and zirconium (Zr). Advanced metallography, scanning electron microscopy, X-ray diffraction, microhardness measurements and electrochemical testing conclusively showed that the importantly elevated Mo content substantially improves corrosion resistance (with a corrosion rate value of 0.64 μm year−1) by promoting the formation of an importantly more flexible passive layer, while simultaneously maintaining mechanical properties closely comparable to those of conventional titanium biomaterials possessing Vickers hardness values around 350 HV. These findings show that an important number of these alloys represent a revolutionary, promising solution for biomedical implants that are safer as well as more durable.