TA15-BT20
TA15-BT20 variety introduction
The nominal composition of TA15 Titanium alloy is Ti-6.5Al-2Zr-1Mo-1V. The main reinforcement mechanism is solid solution reinforcement by α-stable element Al. The addition of neutral elements Zr and β stable elements Mo and V can improve the processability.The alloy has an Al equivalent of 6.58% and Mo equivalent of 2.46%, which is a near α type Titanium alloy with high Al equivalent. Therefore, it not only has the good thermal strength and weldability of α Titanium alloy, but also has the α process plasticity close to β Titanium alloy.
TA15 alloy has moderate room temperature and high temperature strength, good thermal stability and weldability, and its process plasticity is slightly lower than Ti-6Al-4V (Ti Grade 5) alloy.TA15 alloy long-term (3000h) operating temperature up to 500℃, instantaneous (not more than 5min) up to 800℃. At 450℃, the service life can reach 6000h. TA15 alloy is mainly used in the manufacture of aircraft, engine parts and welded bearing parts for long-term operation below 500°C.
Semi-finished products of TA15 alloy include sheet, plate, rolled bar, forged bar, die forging, forgings, extruded profiles, welded rings, solid ring rolled parts and castings.
Semi-finished products of TA15 alloy include sheet, plate, rolled bar, forged bar, die forging, forgings, extruded profiles, welded rings, solid ring rolled parts and castings.
TA15-BT20 alloy chemical composition
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TA15-BT20 alloy properties
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TA15 Heat treatment system
1) Annealing
700-800℃, 15-60min, air-cooled; Bars, forgings, die forgings, thick-wall profiles and parts: 700-850°C, 1-4h, air-cooled.
2) Stress relief annealing
600-650℃, 0.5-8h, air-cooled.
TA15 welding performance
The welding behavior of TA15 alloy is basically similar to that of α alloy, and no stable annealing is required after welding. The intensity of the martensite alpha phase is similar to that of alpha.
The alloy has good welding properties for argon arc welding, contact welding and submerged arc welding. The strength of the weld at room temperature and high temperature is 90%-95% of the strength of the base material.
The alloy has good welding properties for argon arc welding, contact welding and submerged arc welding. The strength of the weld at room temperature and high temperature is 90%-95% of the strength of the base material.
There is almost no difference in strength, bending Angle and impact properties of 2mm thick plate automatic argon arc welding joint in welding state, annealing state after welding and 100h after welding at 450℃.
The joint is not sensitive to heat treatment.
The joint is not sensitive to heat treatment.
Heat treatment process of TA15 parts
In order to eliminate the internal stress caused by parts machining, sheet forming, welding, etc., stress relief annealing is adopted.
The annealing temperature is 600-650℃, and the holding time is 0.5-8h, depending on the complexity of the part or product and the source of internal stress.
TA15 smelting casting process
The alloy should be melted three times in a vacuum consumable electrode arc furnace. Castings are poured in a vacuum consumable arc condensing furnace.TA15 Use recommendations
TA15 Titanium alloys are recommended for various load-bearing components on aircraft and engines.TA15 Application overview and special requirements
TA15 alloy has been widely used in the manufacture of aircraft and engine bearing structures, especially welded bearing parts. When designing parts, the general principles of Titanium alloy part design should be considered, such as: no additional surface protection is required when used in general climatic environments. In Marine climates, stainless steel and nickel-based alloys are allowed to be touched without protection.
When the operating temperature is higher than 300 ° C, protective coatings should be used or the working life should be limited. Reasonable and effective protective measures must be taken for the parts in direct contact with aluminum alloy and structural steel. For Titanium alloy parts with relative motion, in order to prevent fretting wear, barrier coatings should be used. Try to avoid assembling Titanium alloy parts with cadmium-plated steel parts together.
Effect of heat treatment on mechanicl properties of TA15 titanium alloy bars:(a) single heat treatment;(b)dual heat treatment
