Mechanical and electrochemical characterization of Ti–12Mo–5Zr alloy for biomedical application

We have fabricated a new β metastable titanium alloy that comprised of non-toxic elements Mo and Zr. Ingot with composition of Ti–12Mo–5Zr is prepared by melting pure metals in a vacuum non-consumable arc melting furnace. The alloy is then homogenized and solution treated under different temperature. The alloy is characterized by optical microscopy, X-ray diffraction, tensile tests and found to have an acicular martensitic α″ + β structure and dominant β phase for the 1053 K and 1133 K solution treatment samples, respectively. The elastic modulus of the latter is about 64 GPa, which is much lower than those of pure Ti and Ti–6Al–4V alloy. In addition, it had moderate strength and much higher microhardness as compared with Ti–6Al–4V alloy. The results show better mechanical biocompatibility of this alloy, which will avoid stress shielding and thus prevent bone resorption in orthopedic implants applications. As long-term stability in biological environment is required, we have also evaluated the electrochemical behavior in a simulated body fluid (Hank's solution). Potentiodynamic polarization curves exhibits that the 1133 K solution treatment Ti–12Mo–5Zr sample has better corrosion properties than Ti–6Al–4V and is comparable to the pure titanium. The good corrosion resistance combined with better mechanical biocompatibility makes the Ti–12Mo–5Zr alloy suitable for use as orthopedic implants.

► A new β metastable titanium alloy with composition of Ti–12Mo–5Zr that comprised of non-toxic elements Mo and Zr has been developed.
► The elastic modulus of the Ti–12Mo–5Zr alloy is as low as 64 GPa, which is much lower than those of pure Ti and Ti–6Al–4V alloy.
► The Ti–12Mo–5Zr alloy has moderate strength and much higher microhardness as compared with Ti–6Al–4V, which showing better mechanical biocompatibility.
► The corrosion resistance is much higher than that of Ti–6Al–4V in a simulated body fluid (Hank's solution).