Thermal Properties
The thermal properties of grade 9 Ti 3Al 2.5V alloy are tabulated below.
| Properties | Metric | Imperial |
|---|---|---|
| Thermal expansion co-efficient (@20-95°C/68-203°F) | 9.61 µm/m°C | 5.34 µin/in°F |
| Thermal conductivity | 8.30 W/mK | 57.6 BTU in/hr.ft².°F |
Other Designations
Equivalent materials to grade 9 Ti 3Al 2.5V alloy are as follows:
| AMS 4943 | AMS 4944 | ASTM B265 (9) | ASTM B337 (9) |
| ASTM B338 (9) | ASTM B348 (9) | ASTM B381 (9) | DMS 2241 |
| GE B50TF117 | MIL T-9046 | MIL T-9047 | PWA 1260 |
| AMS 4954
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Physical Properties
The physical properties of grade 9 Ti 3Al 2.5V alloy are tabulated below.
| Properties | Metric | Imperial |
|---|---|---|
| Density | 4.48 g/cm3 | 0.162 lb/in3 |
| Melting point | ≤ 1700°C | ≤ 3090°F |
Mechanical Properties
The following table shows mechanical properties of grade 9 Ti 3Al 2.5V alloy.
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | 620 MPa | 89900 psi |
| Yield strength | 530 MPa | 76900 psi |
| Poisson’s ratio | 0.3 | 0.3 |
| Elastic modulus | 100 GPa | 14500 ksi |
| Shear modulus | 44 GPa | 6380 ksi |
| Elongation at break | 20% | 20% |
| Hardness, Vickers | 300 | 300 |
Fabrication and Heat Treatment
Machinability
Although tough, grade 9 Ti 3Al 2.5V alloy can be machined using the right quantity of coolant flow, slow speeds and high feed rates. High-speed tools should be used for tooling this alloy and the recommended tool types are tungsten carbide designations C1-C4 or cobalt based.
Forming
Grade 9 Ti 3Al 2.5V alloy can be hot or cold formed using hydropress, power brake, stretch or drop hammer techniques.
Welding
Weldabilty of grade 9 Ti 3Al 2.5V alloy is rated as good.
Heat Treatment
The material has to be solution heat treated to 871-927°C (1600-1700°F), then held for 15-20 min and water quenched.
Annealing
The material can be fully annealed at 593-760°C (1100-1400°F) for 3 h, and then air cooled. For stress relief, the material has to be heated to 316-649°C (600-1200°F) for 3 h and air cooled.
Forging
Rough forging can be performed at 900°C (1650°F) and completed at 843°C (1550°F).
Hot Working
Hot working enhances the overall ductility of the material.
Cold Working
Cold working features of this material is same as that of austenitic stainless steel. Post-work annealing is recommended to re-attain favorable performance properties.
Aging
For aging grade 9 Ti 3Al 2.5V alloy, the material should be heated to 482-510°C (900-950 °F) for 2 to 8 h and then air cooled.
Applications
Grade 9 Ti 3Al 2.5V alloy is used in the following application areas:
- For tubing in aircraft and engine hydraulic systems
- Golf clubs and tennis rackets
- Performance bicycles