Strain glass state in Ni-rich Ni-Ti-Zr shape memory alloys

This work reports the existence of the strain glass state in Ni-rich Ni-Ti-Zr shape memory alloys in-duced by the precursor stages of the H-phase precipitation, typical of this alloy system. The strain glass is detected from dynamic mechanical testing and microstructural observations by electron diffraction and Transmission Electron Microscopy (TEM). The elastic modulus measurements also suggest the elinvar ef-fect in these alloys. The strain glass state of this material exhibits superelastic effect in compression with recoverable strain levels over 4% and very little temperature dependence of the stress-strain curves over a temperature range of 230 to 300 K. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Automated summary

This study reports the existence of a strain glass state induced by the precursor stages of H-phase precipitation in Ni-Ti-Zr shape memory alloys, with superelastic effect observed in compression. The material exhibits recoverable strain levels over 4% with little temperature dependence of the stress-strain curves.