Phase stability and young's modulus of Ti-Cr-Sn-Zr alloys

In this study, The Young's modulus of Ti-Cr-Sn-Zr quaternary alloys exhibiting a wide compositional range was investigated. The quenched microstructure of these Ti-Cr-Sn-Zr quaternary alloys displayed a transition from martensitic structure to β phase structure depending on the amount of Cr and Zr. The Ti-Cr-Sn-Zr quaternary alloy with meta-stable β phase structure shows minimum values of both Young's modulus and tensile strength, although the Ti-Cr-Sn-Zr quaternary alloy with martensitic structure and stable β phase structure shows higher Young's modulus and strength. The Ti-Cr-Sn-Zr quaternary alloy with the meta-stable β phase shows two step yielding phenomenon in tensile stress-strain curves, in which first yield stress indicates the onset stress of a stress induced martensitic transformation and second yield stress indicates the onset of the slip deformation. The grain size of the Ti-2Cr-6Sn-45Zr quaternary alloy with meta-stable β phase structure influenced its mechanical properties. Although first yield stress decreased and the second yield stress increased when the grain size of this alloy diminished, Young's modulus and the super elastic properties were not influenced greatly.