| Abstrakt: |
Metastable beta titanium alloys are suitable for use in the aerospace industry due to their high strength and good ductility, as well as their high strength -to -weight ratio. The aim of the current research is to investigate the microstructure and tensile properties of the alloy after single -step and two -step aging following thermal -mechanical cycles of single -phase β annealing and two -phase α+β annealing. For this purpose, on one strip of the alloy, solution annealing heat treatment in the single -phase β region, cold rolling and recrystallization and on the other strip, solution annealing heat treatment in the two -phase α+β region was performed. Afterwards, the specimens from the strips were subjected to single -step aging at 550 ⸰C. In addition, in order to perform two -step aging, specimens were subjected to heat treatment at 300 and 550 ⸰C for primary and secondary aging, respectively. Then the structural evolution of the alloy was investigated by SEM and X -ray diffraction pattern and the tensile properties of it by tensile test. It was found that the optimum heat treatment cycle of the Ti -3873 alloy was two -step aging after α+β solution treatment leading to 1190 MPa yield strength and 14.7% elongation. In this case, the obtained structure has no grain boundary alpha and the formed secondary alpha has a length of less than 0.5 µm and its average thickness is 0.15 µm. [ABSTRACT FROM AUTHOR] |
