Toughening heat treatment technique of Ti12LC titanium alloy

The invention discloses a toughening heat treatment technique of Ti12LC titanium alloy. The toughening heat treatment technique of the Ti12LC titanium alloy comprises the following steps that S1, the first stage of solid solution treatment is conducted; S2, furnace cooling is conducted; S3, the second stage of solid solution treatment is conducted; and S4, aging treatment is conducted. The toughening heat treatment technique of the Ti12LC titanium alloy has the following advantages that 1, by the adoption of the heat treatment method of staged solid solution treatment and the aging treatment, a duplex structure composed of 5-30% of primary equiaxial alpha phases, 10-20% of secondary lath alpha phases and lamellar or fine needle-shaped beta transformed structures can be obtained; 2, by controlling the temperatures of the solid solution treatment of the two stages, the volume fractions of the primary equiaxial alpha phases and the secondary lath alpha phases can be adjusted, accordingly, the strength of the Ti1