Ti-3Al-2.5V(Grade 9)

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FORMS WE CAN PROVIDE

Ti-3Al-2.5V(Grade 9) Sheet/Plate
Ti-3Al-2.5V(Grade 9) Rod/Bar
Ti-3Al-2.5V(Grade 9) Tube/Pipe

Ti-3Al-2.5V(Grade 9)

Titanium Grade 9 alloy is a near-α-type titanium alloy with a nominal composition of Ti-3Al-2.5V, which was developed as a cold-workable pipe application. At room temperature and high temperature, its strength is 20% to 50% higher than pure titanium, and its welding performance and cold forming performance are better than Ti-6Al-4V(Grade 5) alloy. Titanium Grade 9 alloy is generally used in the annealed state, and can also be used in the cold-worked and stress-relieved annealed state. The maximum operating temperature is about 315°C.
Titanium Grade 9 alloy seamless pipe is suitable for hydraulic and fuel pipeline systems of aircraft and engines. It can also be rolled into foil and strip. The former is mostly used in airplane honeycomb structures.

Ti-3Al-2.5V(Grade 9) chemical composition (mass fraction) %

Grade Alloy Element Impurities≤
Al V Ti Fe C N H O Y Other Element
Single Total
Ti-3Al-2.5V(Grade 9) 2.5~3.5 2.0~3.0 Balance 0.3 0.05 0.025 0.015 0.12 0.005 0.1 0.4

Forms of Ti-3Al-2.5V(Grade 9) We Can Provide

Physical and chemical properties of Ti-3Al-2.5V(Grade 9)

1. Melting temperature is 1700~1726℃
2. Density ρ=4.47g/cm3

3. Thermal conductivity

Thermal conductivity
θ/℃ 100 200 300 400 500 600 700 800
λ/W·m-1·K-1 11.7 13 13.4 14.2 14.7 16.3 17.6 19.3
4. Specific heat capacity
The specific heat capacity at room temperature is 858J/(kg.K)

5. Coefficient of linear expansion

Coefficient of linear expansion
θ/℃ 100 200 300 400 500 600 700 800
α/10-6·K-1 8.77 9.56 9.66 9.7 9.65 9.68 9.84 9.73

6. Resistivity

Resistivity
θ/℃ 20 100 200 300 400 500 600 700 800
ρ/μΩ·m 1.25 1.31 1.42 1.52 1.6 1.66 1.71 1.74 1.74
7. Magnetic properties
Non-magnetic
8. Antioxidant properties
The oxidation resistance temperature of the alloy can reach 316°C. At 800°C, keep it for 1 hour, and the surface oxidation depth does not exceed 0.05mm.

9. Corrosion resistance
The general corrosion performance is similar to that of industrial titanium.

Corrosion resistance
Thermal exposure stress/MPa 294
Heat exposure temperature/℃ 350 400 450
Amount of salt applied to the surface/mg.cm-2 0 10.1 17 0 36.5 0 1.6 3.0～7.7
Heat exposure time/h 100 100 100 100 100 53.3 45.9 4.8
Room temperature tensile strength/MPa 738 739 760 746 742 0 0 0
10. Hot salt stress corrosion performance

Phase Transformation and Microstructure of Ti-3Al-2.5V(Grade 9)

Phase transition temperature

α+β↔β transition temperature 925°C±10°C

Microstructure

The structure of the alloy in the annealed state is mainly equiaxed α phase and a small amount of β phase. In the cold-worked state, it presents an elongated α structure. In the solid solution aging state, it is equiaxed α phase and β transformation structure.

Phase transition temperature

Start: 560°C; End: 700°C

Manufacturing process and properties of Ti-3Al-2.5V(Grade 9)

Heat treatment process

Ordinary annealing

Plates, bars, pipes, forgings: 650℃~800℃, 0.5~2h, air cooling

Vacuum annealing

650 ℃ ~ 790 ℃, 0.5 ~ 2h, furnace cooling to below 200 ℃ out of the furnace air cooling, the absolute pressure in the furnace should not exceed 9 x 10-2Pa

Stress relief annealing

Removal of internal stress formed during parts forming, welding and machining annealing: 370°C~600°C, 0.5~4h, air cooling and furnace cooling.

Application of Ti-3Al-2.5V(Grade 9)

As early as the 1970s, Ti-3Al-2.5V(Grade 9) was used as hydraulic, fuel and other pipeline systems on various high-tech military, aerospace and civil aircrafts in the United States. It was also used in the air conditioning pipelines of my country’s transport aircraft in the early 1990s and will be used in aero engines. Application in piping system. In recent years, it has been used as a fire gun with a complex shape, medium strength, and weldable flamethrower.
Ti-3Al-2.5V(Grade 9) has also achieved good applications in various civil industries, such as: oil exploration well instrument jacket pipe fittings, heat exchanger pipe fittings, titanium fishing rod body, spectacle frame profiled wire, golf clubs, etc.