Structure and mechanical properties of annealed α + β titanium alloys

BT6 and BT22 alloy semiproducts with fine-grained, well-developed structure, obtained by deformation in the α+β-region, and with coarse plate structure, obtained by annealing in the β-region are investigated. The optimal parameters of the plate structure and corresponding mechanical properties of some α+β-alloys are presented. It is established that change of the structure parameters differently affects the fracture toghness and fatigue characteristics. It is shown that an increase of parameters of the plate structure results in a sharp decrease of durability while equiaxial α-grains size does not affect this characteristics