AGE-HARDENING OF VT35 TITANIUM-ALLOY

VT35 alloy belongs to beta-titanium alloys that preserve the body-cent ered lattice of the beta-phase in hardening from the beta-region. in a n equilibrium state this alloy has an alpha + beta structure. Alter ha rdening, VT35 alloy has a high ductility and a low strength. The subse quent single- or double-stage aging in the biphase region promotes con siderable strengthening of the alloy due to segregation of a second ph ase. VT35 titanium alloy is hardened to a ''pure'' beta-phase by cooli ng from the single-phase region in water, in air, or with the furnace (at a rate of at least 3 - 4 deg/min). This special feature of the all oy is caused by its chemical composition (Ti - 3% Al - 15% V - 3% Ct - 3% Sn), which provides a high coefficient of beta-stabilization K-bet a = 1.5. The present paper concerns the processes of age toughening of a hardened VT35 alloy and the kinetics of the structural transformati ons in such a treatment.