Effects of different processing conditions on super-elasticity and low modulus properties of metastable β-type Ti-35Nb-2Ta-3Zr alloy

摘要

AbstractIn this work, by means of X ray diffraction, polarizing microscope, transmission electron microscope and mechanical properties test, the microstructure and mechanical properties of metastable β-type Ti-35Nb-2Ta-3Zr alloy were systematically studied by two different processing techniques. The results showed that there was a large amount of lath martensite in this alloy solution-treated by 1053?K for 30?min, and recrystallization occurred, but the grain growed again and became coarse equiaxed crystal. However, the alloy annealed by 923?K for 10?min undergone recrystallization inside the grains, and many fine grains appeared. In addition, a large number of dislocations and grain boundaries that provided adequate heterogeneous nucleation conditions for β phase during annealing to promote the transformation α″ phase into β phase, so as to reduce the content of α″ phase and stabilize β phase. Therefore, the annealed specimens had lower elastic modulus (55?GPa) and higher super-elasticity (47.94%) than the solution treated specimens.Highlights?Based on modulus (E) and superelasticity (SE), a new metastable β Ti alloy was prepared.?