Biocorrosion study of titanium‐cobalt alloys

SUMMARY The present work provides experimental results of corrosion behavious in Hank's physiological solution and some other properties of in‐house fabricated titanium‐cobalt alloys with cobalt ranging from 25–30% in weight. X‐ray diffraction (XRD) shows that, in water‐quenched (WQ) alloys, betatitanium is largely retained, whereas in furnace‐colled (FC) alloys, little beta‐titanium is found. Hardness of the alloys increases with increasing cobalt content, ranging from 455VHN for WQ Ti‐25 wt% Co to 525VHN for WQ Ti‐30 wt% Co. Differential thermal analysis (DTA) indicates that melting temperatures of the alloys are lower than that of pure titanium by about 600°C. Potentiodynamic polarization results show that all measured breakdown potentials in Hank's solution at 37°C are higher than 800mV. The breakdown potential for the FC Ti‐ 25 Wt% Co alloy is even as high as nearly 1200mV.