On the mechanical biocompatibility of Ti-15Zr-based alloys for potential use as load-bearing implants

Abstract

This study evaluated the mechanical properties and cytocompatibility of recently developed Ti-15Zr-based alloys with Mo addition for potential use as load-bearing implants. The phase composition and microstructure were changed by the alloying elements, being the β phase fully retained on the Ti-15Zr-10Mo and Ti-15Zr-15Mo samples. The TEM analysis showed that a small quantity of ω phase was precipitated on the samples with a high amount of Mo. Regarding the mechanical properties, the Ti-15Zr-10Mo sample presented high mechanical strength and large elongation (854 ± 63 MPa and 18.7 ± 2.8 %). However, the Ti-15Zr-15Mo sample exhibited better mechanical compatibility, due to its combination of low Young’s modulus (75 ± 1 GPa) and high Vickers microhardness (346 ± 4 HV). Some dimple-type structures found along the fractured surface confirmed the ductile behavior of these samples. The MTT test indicated non-cytotoxic effects of all samples when in contact with osteoblastic cells (p < 0.05). The wettability values of the samples were adequate for biomedical applications. The mechanical properties of the Ti-15Zr-15Mo sample were better than some commercial metallic biomaterials, which highlights its great potential for use as load-bearing implants. Keywords: Ti-Zr-Mo alloy, Mechanical properties, Load-Bearing implant, Biomaterial.