Titanium Grade 5, also known as Ti-6Al-4V, is the most widely used titanium alloy.
It is an alpha-beta titanium alloy combining high strength, relatively low density, good fatigue performance and excellent corrosion resistance. These properties make Grade 5 important in aerospace, defence, marine and high-performance engineering applications.
Grade 5 is designated UNS R56400. The name Ti-6Al-4V describes the alloy’s approximate nominal aluminium and vanadium contents. It should not be interpreted as an exact chemical composition.
Grade 5 Chemical Composition
| Element | Weight % |
|---|---|
| Titanium (Ti) | Balance |
| Aluminium (Al) | 5.5–6.75 |
| Vanadium (V) | 3.5–4.5 |
| Oxygen (O) | ≤ 0.20 |
| Iron (Fe) | ≤ 0.40* |
| Carbon (C) | ≤ 0.08 |
| Nitrogen (N) | ≤ 0.05 |
| Hydrogen (H) | ≤ 0.015 |
*The exact iron limit can vary with specification and product form.
Grade 5 Mechanical Properties
Representative minimum properties for commonly supplied annealed sheet and plate include approximately:
| Property | Value |
|---|---|
| Ultimate tensile strength | ≥ 895 MPa |
| 0.2% yield strength | ≥ 828 MPa |
| Elongation | ≥ 10% |
| Density | approximately 4.43 g/cm³ |
Bar and other product forms may have different minimum requirements.
Fabrication and Machining
Grade 5 can be welded successfully when the weld and heat-affected area are adequately shielded from oxygen, nitrogen and hydrogen while hot.
Machining is more demanding than conventional steels or aluminium alloys because titanium has low thermal conductivity, retains strength at cutting temperatures and can react with cutting tools. Suitable tooling, rigid setups, controlled cutting speeds and adequate coolant are important.
Its room-temperature formability is also lower than commercially pure titanium and Grade 9.
Elevated-Temperature Use
Ti-6Al-4V is commonly used for elevated-temperature applications to around 325°C. Less-critical applications may extend towards 400°C depending on stress, exposure time, material condition and the governing design criteria.
Typical Applications
- Aircraft structural components
- Jet-engine compressor components
- Aerospace fasteners
- Forgings
- High-strength marine components
- Defence applications
- Industrial equipment
- High-performance motorsport components
- Sporting equipment
Common Specifications
- ASTM B265
- ASTM B348
- ASME SB-265
- AMS 4911 for sheet, strip and plate
Technical Note
Chemical and mechanical properties shown are representative of commonly referenced specifications. Requirements can vary by product form, thickness, heat treatment and governing standard. Material should be ordered to the required specification, and the supplied material test report (MTR) should be used to verify compliance.
