Thermal Properties
The thermal properties of grade 23 Ti 6Al 4V ELI alloy are tabulated below.
| Properties | Metric | Imperial |
|---|---|---|
| Thermal expansion co-efficient (@20-100°C/68-212°F) | 8.60 µm/m°C | 4.78 µin/in°F |
| Thermal conductivity | 6.70 W/mK | 46.5 BTU in/hr.ft².°F |
Mechanical Properties
The following table shows mechanical properties of grade 23 Ti 6Al 4V ELI alloy.
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | 860 MPa | 125000 psi |
| Yield strength | 790 MPa | 115000 psi |
| Poisson’s ratio | 0.342 | 0.342 |
| Elastic modulus | 113.8 GPa | 16510 ksi |
| Shear modulus | 44.0 GPa | 6380 ksi |
| Elongation at break | 15% | 15% |
| Hardness, Brinell | 326 | 326 |
| Hardness, Knoop | 354 | 354 |
| Hardness, Rockwell C | 35 | 35 |
| Hardness, Vickers | 341 | 341 |
Physical Properties
The physical properties of grade 23 Ti 6Al 4V ELI alloy are tabulated below.
| Properties | Metric | Imperial |
|---|---|---|
| Density | 4.43 g/cm3 | 0.160 lb/in3 |
| Melting point | 1604 – 1660°C | 2919 – 3020°F |
Other Designations
Equivalent materials to grade 23 Ti 6Al 4V ELI alloy are as follows:
- AMS 4907
- AMS 4931
- ASTM F136
- ASTM F467 (TI-5)
- ASTM F468 (5)
- ASTM F468 (S)
- MIL F-83142
- MIL T-9046
- MIL T-9047
- SPS M618
- AMS 4930
- AMS 4956
Fabrication and Heat Treatment
Machinability
Grade 23 Ti 6Al 4V ELI alloy can be machined using slow speeds, right quantity of coolant flow 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 23 Ti 6Al 4V ELI alloy can be hot or cold formed. Forming techniques include hydropress, stretch or drop-hammer.
Welding
Weldability of grade 23 Ti 6Al 4V ELI alloy is rated as fair.
Heat Treatment
The material can be solution treated at 904-954 °C (1660-1750°F) for 2 h, and then water quenched.
Annealing
For annealing grade 23 Ti 6Al 4V ELI alloy, the material has to be held at 732°C (1350°F) for about 1/4 and 4h. It should then be furnace cooled to 566°C (1050°F) then air cooled.
Forging
Rough forging can be performed at 982°C (1800°F), and completed at 968°C (1750°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
Aging of grade 23 Ti 6Al 4V ELI alloy can be performed at 538°C (1000°F) for 4 h and air cooled.
Applications
Grade 23 Ti 6Al 4V ELI alloy is used in the following areas:
- Surgical implants
- Aircraft components
- Structural components
- In a variety of salt water applications
- In high pressure cryogenic vessels down to -320°C
- In applications requiring excellent fracture toughness and fatigue strength.