Titanium Grade 23, also known as Ti-6Al-4V ELI (Extra-Low Interstitial), is a high-purity version of Titanium Grade 5. Reduced oxygen, nitrogen, carbon, and iron content significantly improve fracture toughness, ductility, and fatigue resistance, making it ideal for safety-critical applications.
Material Classification
| UNS | R56407 |
|---|---|
| Alloy Type | Alpha-Beta Titanium Alloy |
| Key Feature | Extra-low interstitial content |
| Heat Treatable | Yes (Solution Treated & Aged) |
Chemical Composition (Typical)
| Element | Content (%) |
|---|---|
| Aluminum (Al) | 5.5 – 6.5 |
| Vanadium (V) | 3.5 – 4.5 |
| Oxygen (O) | ≤ 0.13 |
| Iron (Fe) | ≤ 0.25 |
| Nitrogen (N) | ≤ 0.05 |
| Carbon (C) | ≤ 0.08 |
| Hydrogen (H) | ≤ 0.012 |
Mechanical & Physical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength | 860 – 930 MPa |
| Yield Strength | 795 – 860 MPa |
| Elongation | 10 – 15% |
| Elastic Modulus | ~110 GPa |
| Density | ~4.43 g/cm³ |
| Fracture Toughness | Very high |
Metallurgical Characteristics
Grade 23 has an α + β microstructure and is fully heat treatable. Lower interstitial content improves microstructural uniformity, cryogenic performance, and weldability. Machinability is slightly better than Grade 5 due to improved ductility.
Corrosion & Biocompatibility
Titanium Grade 23 offers outstanding resistance to body fluids, seawater, chlorides, and atmospheric corrosion. It is non-toxic, non-magnetic, and fully biocompatible, making it one of the most widely used implant materials globally.
Applications
Medical & Biomedical: Orthopedic implants, dental implants, trauma plates, screws, rods
Aerospace: Cryogenic components, structural parts, high-fatigue fasteners
High-Performance Engineering: Motorsport parts, precision lightweight structures
Advantages
✔ Exceptional biocompatibility
✔ Superior fracture toughness
✔ Excellent fatigue resistance
✔ High strength-to-weight ratio
✔ Outstanding corrosion resistance
Limitations
⚠ Higher cost than Grade 5
⚠ Slightly lower strength than Grade 5
⚠ Precision processing required for medical use
Grade 23 vs Grade 5
| Property | Grade 23 (ELI) | Grade 5 |
|---|---|---|
| Oxygen Content | Lower | Higher |
| Strength | Slightly lower | Higher |
| Toughness | Much higher | Lower |
| Fatigue Resistance | Excellent | Very good |
| Biocompatibility | Excellent | Limited |
Summary:
Titanium Grade 23 (Ti-6Al-4V ELI) is engineered for maximum toughness,
fatigue resistance, and biocompatibility. It is the gold standard for
medical implants and trusted for aerospace and high-reliability systems
where failure is not an option.