Effect of Zr Addition on Martensitic Transformation in TiMoSn Alloy

Abstract

The effects of Zr addition on martensitic transformation and the lattice parameters of α” (orthorhombic) martensite and β (bcc) phase were investigated in Ti-3mol%Mo-6mol%Sn based alloys containing up to 4mol%Zr using θ-2θ X-ray diffraction measurement (XRD) and differential scanning calorimetry (DSC). It was found by XRD that orthorhombic α” martensite phase is formed when Zr content is 0 to 2mol% while bcc β phase also existed in the alloy containing 2 to 4mol%Zr. Based on the lattice parameters in α” martensite and β parent phases evaluated, the transformation strains between α” and β phase calculated become slightly small with increasing Zr content. DSC revealed that, with increasing Zr content, reverse martensitic transformation start and finish temperatures decreased down to 410K with a rate of-30K/mol%Zr. It is concluded in the Ti-Mo-Sn alloy system that Zr addition stabilizes β phase and that Zr addition is effective to control martensitic transformation temperature without changing the transformation strains largely.

Phase Constitution and Mechanical Properties of Ti‐Mo‐Sn‐Zr Shape Memory Alloys

“…Then, it can be said that Zr addition to Ti-5Mo-3Sn alloys stabilizes the phase, and that the martensitic transformation temperature decreases with increasing Zr content. These are in good agreement with our previous study [16].…”

“…All the lattice parameters are listed in Table 1. It was found that the a increased with increasing Zr content, and this result was consistent with the previous study [16]. Besides, another phase such as phase was not detected.…”

“…These lattice deformation strains were larger than those of Ti-27Nb (2.55% [2]) and Ti-24Nb-3Al (2.9% [17]). Since the lattice deformation strain is not strongly dependent of Zr content in Zr added Ti-3Mo-6Sn alloys, the lattice deformation strain of Ti-5Mo-3Sn alloys is not largely changed by Zr addition [16].…”

“…In our previous research, it was reported that the biocompatibility of a Ti-3Mo-6Sn-5.2Zr alloy is comparable to the pure Ti [15]. In addition, it was also reported that Zr addition to Ti-Mo-Sn alloy decreases the martensitic transformation temperature by 42 K / mol%Zr with small change of the lattice deformation strain [16]. Thus, Zr addition to Ti-Mo-Sn alloy must bring relatively large shape recovery strain in addition to decrease in M s .…”

Effect of Annealing Temperature on Microstructure and Superelastic Properties of Ti-Au-Cr-Zr Alloy

“…Ti-Nb, 5) TiNb Al, 6) Ti-Nb-Zr, 7) TiNbTaZr 8) and Ti-Nb-Mo 9) ), Ti-Mo base alloys (e.g. Ti-Mo-Al, 10) Ti-Mo-Sn 11) and Ti-Mo-SnZr 12) ) and Ti-Ta base alloys (e.g. Ti-Ta 13) and Ti-Ta-Sn 14) ).…”