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Titanium and its alloys have been used extensively in the last few decades as materials for orthopedic and dental implants and other medical devices due to their high strength, low modulus, and high corrosion resistance in biological media. Besides other important material features, the corrosion parameters and corrosion products are responsible for limiting the biocompatibility of metallic materials, and can produce undesirable reactions in implant-adjacent and/or more distant tissues. Electrochemical corrosion behaviors of novel beta titanium alloys, Ti-4.7 Mo-4.5 Fe, Ti-3Mo-0.5 Fe and Ti-2Mo-0.5 Fe were investigated in naturally aerated Ringer’s solution at room temperature compared with currently used biomedical titanium alloy, Ti-6Al-4V. Very low current densities were obtained from the potentiodynamic polarization curves, indicating a passive behavior for all the studied alloys. Electrochemical impedance spectroscopic (EIS) studies showed high impedance values for all samples indicating an improvement in corrosion resistance of the spontaneous oxide layer. The fitting data obtained suggests a single passive layer form on the virgin surfaces of the alloys. The EIS results exhibited capacitive behavior (high corrosion resistance) with phase angles close to-80 C and high impedance values at low and medium frequencies, which are indicative of the formation of a highly stable film on these alloys in the test solution. The new present alloys are promising metallic biomaterials for the future, owing to their very low elastic modulus and good corrosion resistance capabilities.

Recently, researchers has given attention to the low‐cost Ti‐alloys with low Young's modulus for biomedical applications. This can be done by substituting partially or totally the expensive rare metals with the common low‐cost elements. In such a way, the low‐cost Ti‐2Mo‐0.0∼2.0 Fe alloy system is studied. The elastic modulus of the Ti‐2.0Mo alloys containing 0.0∼1.0 Fe is of low value of approximately 80∼85GPa where the a'‐ and a"‐martensite phases are present. In this alloy system, the hardness is relatively high and increases monotonously with increasing the Fe‐content. The corrosion resistance of Ti‐2Mo‐0.5Fe alloy is higher than Ti‐6Al‐4V alloy. The cell viability is also very high (above 100%). Among the studied alloys, Ti‐2.0Mo‐0.5Fe alloy seems to be a candidate alloy for low‐cost bone replacement materials with low Young's modulus and to replace the commercial Ti‐6Al‐4V alloy.