TC11 Titanium Alloy Material Details
TC11 Overview
TC11 alloy has good comprehensive properties α-β T-type thermal strength titanium alloy has excellent thermal strength properties (high temperature strength, creep resistance, etc.) below 500 ℃, and has higher room temperature strength. The alloy also has good hot working processability (including conventional process properties and superplasticity), and can be welded and machined in various ways. At present, with the continuous expansion of the application of TC11 alloy β Heat treatment and isothermal forging have developed rapidly.
The alloy is mainly used to manufacture compressor disk, blade, drum and other parts of aeroengine, and also can be used to manufacture aircraft structural parts. adopt α+β Zone thermal deformation and α+β The ZUI high long-term working temperature of TC11 alloy obtained by zone heat treatment is 500 ℃. The semi-finished products produced include bars, forgings, die forgings and castings.
TC11 Heat Treatment System
(1) Double annealing: 950 ℃, 1-2h, air cooling+530 ℃, 6h, air cooling. The first annealing temperature is allowed to be β Make appropriate adjustment within the range of 30-50 ° C below the phase transition point. The holding time of the first annealing is determined according to the thickness of the large section of ZUI: 1h if the thickness is less than 25mm; 1.5h for 26-50mm; 51-75mm is 2h.
(2) Stress relief annealing: 530-580 ℃, 0.5-6h, air cooling or furnace cooling.
TC11 smelting and casting process
The alloy shall be melted by vacuum consumable electrode electric arc furnace more than twice.
TC11 Application Overview and Special Requirements
The alloy has been used to manufacture compressor disk, blade and other aviation parts of turbojet engine. Due to the limitation of thermal stability and creep, the allowable working time of the alloy is 6000h at 450 ° C and 500h at 500 ° C.
TC11 welding performance
(1) The alloy can be applied to welded structures. Inert gas (argon, helium) or vacuum method must be used to protect fusion welding. The weld shall be free of oxidation color or light yellow.
(2) Due to the large thermal cycle reaction of the alloy to welding, some special heat treatment is required, which is not only to eliminate residual stress, but also to stabilize the structure and properties of the weld and the metal adjacent to the weld. It is generally recommended to conduct annealing and air cooling or furnace cooling after welding. Annealing is carried out in vacuum furnace or inert gas container, and it is not allowed to use flame spray gun for annealing.
Heat treatment process of TC11 parts
In the double annealing process of actual parts (especially large section forgings), pay attention to the air cooling conditions of the first annealing, and do not allow stack cooling or air cooling at the bottom of the bottom extraction furnace, so as not to affect the structure and properties (especially reduce the tensile strength) due to the slow cooling rate.
TC11 usage suggestions
It is recommended to select TC11 alloy for manufacturing compressor disk, blade, drum and other parts with operating temperature below 500 ° C on various aeroengines.
