Structure and Superelasticity of Novel Zr-Rich Ti-Zr–Nb Shape Memory Alloys

Two novel superelastic Ti-41Zr-8(10)Nb alloys were studied and compared to the reference Ti-18Zr-15Nb alloy (all in at. %) terms of their microstructure mechanical properties. A thermomechanical treatment consisting cold rolling post-deformation annealing was applied all create conditions for behavior at room temperature. X-ray diffraction analysis demonstrated considerably larger lattice distortions both parent martensitic phases Zr-rich that resulted significantly higher theoretical limits recovery strain these (~ 8.0%) as 5.5%). However, during temperature fatigue testing, accumulated considerable residual strains showed a relatively weak resistance caused by presence notable quantities α″-phase this Conversely, containing only β-phase testing therefore, more favorable phase composition manifested better superelasticy, resistance. Nonetheless, an excellent combined effect shape memory superelasticity indicates could be improved via additional adjustment chemical composition.