Texture evolution, microstructure, and superelastic properties of different cold-rolled Ti-Zr-Nb-Sn strain glass alloys

Abstract

In order to further reveal the effect of Ti-18Zr-12.5Nb-2Sn alloys with different cold rolling on the microstructure, transformation behavior, and superelastic properties, in-situ X-ray diffraction, in-situ laser scanning confocal microscopy, electron backscatter diffraction, and tensile tests have been carried out. We found that the ultimate tensile strength decreased from 696 MPa to 594 MPa, and the fracture strain increased from 23% to 38%, as the percentage of cold rolling increased from 75% to 99%. Moreover, the superelastic recovery strain was optimized to 5.15% with the increase in the percentage of cold rolling, which is attributed to the evolution of the stronger {001}β 〈011〉β-type texture under large cold deformation of solution treatment. The strain glass behavior of the samples was regulated by varying the percentage of cold rolling; the ideal freezing temperature gradually decreased from 248.5 K to 174.2 K with increase in percentage of cold rolling. Finally, the stress-induced entropy change ∼10.5 J/(kg K) for a temperature range of ∼105 K was obtained after the training sample thirty times.