Micro folding structure using Ti-Ni-Zr high formable shape memory alloys

In this study, we proposed the fabrication process of the micro folding structures such as foldable pipe structures using Ti-Ni-Zr high formable shape memory alloys (HFSMAs). We investigated microforming ability, shape memory behaviors of Ti
₃₈
Ni
₅₀
Zr
₁₂
(at.%) HFSMAs. We succeeded to fabricate folded samples without crystallization. Their folding angles 0were approximately 60° and 90°. Finally, folded samples were annealed at 873 K for 1 hour, and then they became SMAs. To investigate their shape memory behaviors, bending tests during several thermal cycles were conducted. As these results, both folded samples showed good shape memory behaviors, and could recover their initial shapes without plastic deformation, even if they were deformed to straight shape (0=180°).