Superelastic behavior of ultrafine-grain-structured Ti-35 wt%Nb alloy fabricated by equal-channel angular extrusion

Abstract

The superelasticity of a Ti-35 wt% Nb alloy has been explored by fabricating an ultrafine-grain-structured specimen through equal-channel-angular-extrusion processing. A complete superelasticity of 3.5% was realized by refining the grain size down to about 0.25 mm and by inducing the precipitation of an omega-phase. The superelasticity was possible because the beta-phase was largely stabilized at room temperature as a result of the severe grain refinement and Nb-enrichment in the matrix on account of the omega-precipitation.