Mechanical Properties of Cast Ti-Fe-O-N Alloys

A recent addition to existing titanium alloys is the Super-TIX™ series (Nippon Steel Corp., Japan), which has intermediate strength between the strengths of CP Ti and Ti-6Al-4V as a result of balancing the Fe, O, and N concentrations. Two alloys in this series were investigated: Ti-1%Fe-0.35%O-0.01%N (Super-TIX800™; LN) and Ti-1%Fe-0.3%O-0.04%N (Super-TIX800N™; HN). These alloys were are-melted and cast using an investment casting method, and their mechanical properties were examined. The yield strength (∼600 MPa) and tensile strength (∼680 MPa) were approximately 33 and 29% higher, respectively, than the corresponding strength of cast CP Ti (ASTM Grade 2). Their percent elongation was somewhat (but not significantly) higher (2–3 %) than that of Ti-6A-4V. On the other hand, the elongation of CP Ti was approximately 7 %. The moduli of elasticity of the alloys ranged from 100–120 GPa. These Ti-Fe-O-N alloys exhibit higher uniaxial yield and tensile strengths than CP Ti, which is currently used for dental applications.