On the Relation between Microstructure, Texture and Tensile Deformation Behavior of Ti3A12. 5V Alloy at Room Temperature

摘要

Microstructural and textural characterization of Ti 3A1 2. 5V alloy sheet is carried out by Electron BackScatter Diffraction and X-ray diffraction pole figure measurement. The partially recrystallized material is tensile tested in the transverse direction in order to understand the relationships governing the tensile deformation behavior of this alloy. Particularly, the influence of microstructure and crystallographic texture on strain localization and yield point phenomena is analyzed. All the stress-strain curves of the transverse direction tested sheets show a stress drop immediately after yielding, which is followed by premature necking and a ductile fracture at around 20% true strain. Thermal measurements performed during the tensile test show that strain localization occurs early in the tensile test causing necking and rupture without strain hardening. These results suggest that the premature strain localization leading to rupture,combined with the strong anisotropy caused by crystallographic texture can explain the anomalous plastic behavior, while the low dislocation density in recrystallized grains may explain the occurrence of yield point phenomena.