Microstructure and Texture Evolution in Double-Cone Samples of Ti-6Al-4V Alloy with Colony Preform Microstructure

摘要: Heat-treated Ti-6Al-4V forged bar with colony microstructure was machined into double-cone-shaped samples for a series of isothermal uniaxial compression test at 1223 K (950 °C) varying constant crosshead speeds 12.5, 1.25, and 0.125 mms−1 to height reduction 70 pct. Another set deformed under the same conditions were heat treated 1173 K (900 °C) an hour followed by water quench. Finite element modeling used provide strains, strain rates, temperature profiles hot samples, texture evolution examined four positions on each sample, representative different ranges. Lamellae fragmentation kinking are dominant microstructural features lower range up maximum 2.0, whereas globularization dominates strains above 2.0 as-deformed samples. The fraction generally increases strain, or post-deformation treatment, but fluctuates strain. grain size globular α is almost maximizes lowest speed due longer deformation time. also coarsens because its increasing level. With respect evolution, basal transverse ring another component 30 deg from ND determined 12.5 mms−1, which consistent increase close β-transus simulation results. type remains unchanged intensity increased spreads