Ultrafine-grained Ti-Nb-Ta-Zr alloy produced by ECAP at room temperature

摘要: To ascertain the influence of severe plastic deformation (SPD) on a Ti–Nb–Ta–Zr (TNTZ) alloy, we studied room temperature mechanical behavior and microstructural evolution an ultrafine-grained (UFG) Ti–36Nb–2Ta–3Zr (wt%) alloy prepared via equal-channel angular pressing (ECAP) as-hot-extruded alloy. The tensile behavior, phase composition, grain size, preferred orientation, dislocation density UFG processed under different conditions, were analyzed discussed. Compared to ECAP-processed TNTZ (3 passes) exhibited approximately 40 88 % increase in average ultimate strength yield strength, respectively. Moreover, as number ECAP passes increased from 3 6, not only expected values, but also slight elongation. Our results suggest that mechanisms govern coarse grained (CG) during involve combination stress-induced martensitic transformation activity. In case mechanism is proposed two components: first, activity induced by strain field imposed ECAP; second, formation α″ martensite early stages which eventually transforms into β continued deformation. We propose governing strongly depends size phase.