Titanium alloy heat treatment

The commonly used heat treatment methods include annealing, solid solution, and aging treatment. Annealing is used to eliminate internal stress, improve plasticity and structural stability, in order to obtain better comprehensive properties. usually α Alloy and（ α+β） The annealing temperature of the alloy is selected at（ α+β） - → β 120~200 ℃ below the phase transition point; Solution and aging treatment is to rapidly cool from high temperature zone to obtain martensite α′ Metastable β Phase, and then insulation in the intermediate temperature zone to decompose these metastable phases, resulting in α Fine dispersed second phase particles such as phases or compounds achieve the goal of strengthening the alloy. Usually（ α+β) Quenching of alloys（ α+β) - → β Conduct at 40~100 ℃ below the phase transition point, metastable β Alloy quenching（ α+β) - → β Conduct at 40-80 ℃ above the phase transition point. The aging treatment temperature is generally 450~550 ℃.
In summary, the heat treatment process of titanium alloys can be summarized as follows:
(1) Stress relieving annealing: The purpose is to eliminate or reduce residual stresses generated during the processing. Prevent chemical erosion and reduce deformation in some corrosive environments.
(2) Complete annealing: The purpose is to achieve good toughness, improve processing performance, facilitate re processing, and improve the stability of size and structure.
(3) Solution treatment and aging: The purpose is to improve its strength, α Titanium alloy and stable β Titanium alloys cannot undergo strengthened heat treatment and only undergo annealing during production. α+β Titanium alloy and containing a small amount α Metastable phase β Titanium alloys can be further strengthened through solid solution treatment and aging.
In addition, in order to meet the special requirements of workpieces, dual annealing, isothermal annealing, and β Metal heat treatment processes such as heat treatment and deformation heat treatment.