Ti-6Al-4V ELI (ASTM Grade 23) is widely used in aerospace and medical applications due to its balanced strength, corrosion resistance, and biocompatibility.
For engineers and buyers, key parameters such as Young’s modulus, tensile strength, and fatigue performance are critical when selecting this alloy. This guide summarizes the mechanical properties, chemical composition, and practical applications of Ti-6Al-4V ELI to support specification and procurement decisions.
Alloy Overview
Ti-6Al-4V ELI (ASTM Grade 23 Titanium, UNS R56401) is a high-purity version of Ti-6Al-4V (Grade 5), with lower interstitial elements (oxygen, nitrogen, iron) to enhance ductility and fracture toughness. It is classified as a medium-to-high strength general-purpose alloy, renowned for superior damage tolerance, biocompatibility, and a balanced combination of high strength, lightweight properties, and corrosion resistance.
Key Distinction: Compared to Grade 5, Grade 23 offers better ductility, fracture toughness, and fatigue strength, making it ideal for critical applications like medical implants and high-performance aerospace components.
Chemical Composition (Weight %)
The Young’s modulus of Ti-6Al-4V ELI typically ranges from 105 to 120 GPa, indicating moderate stiffness compared to steel.
This balance between stiffness and flexibility makes it suitable for:Aerospace structural components requiring fatigue resistance
Medical implants where load transfer compatibility is important
High-performance engineering systems under cyclic stress
Compared to stainless steel, titanium alloys offer lower modulus but better strength-to-weight ratio, which is critical in weight-sensitive applications.
| Component | Content Range |
| Al | 5.5 – 6.5 |
| V | 3.5 – 4.5 |
| C | Max 0.08 |
| Fe | Max 0.25 |
| H | Max 0.0125 |
| N | Max 0.03 |
| O | Max 0.13 |
| Ti | 88.1 – 91 (balance) |
Physical Properties
| Property | Metric | English | Comments |
| Density | 4.42 g/cc | 0.16 lb/in³ | Typical |
| Electrical Resistivity | 0.000168 ohm-cm | 0.000168 ohm-cm | |
| Magnetic Permeability | 1.00005 | 1.00005 | At 20 oersteds |
Mechanical Properties
| Property | Metric | English | Notes |
| Tensile Strength (Ultimate) | Min 860 MPa | Min 125,000 psi | Longitudinal |
| Tensile Strength (Yield, 0.2%) | Min 795 MPa | Min 115,000 psi | Longitudinal |
| Elongation at Break | Min 10% | Min 10% | Longitudinal |
| Reduction of Area | Min 25% | Min 25% | Longitudinal; for 0.187–<1.75 inch material |
| Modulus of Elasticity | 105 – 120 GPa | 15,200 – 17,400 ksi | Typical |
| Poisson’s Ratio | 0.31 | 0.31 | |
| Shear Modulus | 41 – 45 GPa | 5,950 – 6,530 ksi | |
| Minimum Bend Radius | 5t | 5t | For 0.078 in (2 mm) sheet |
Thermal Properties
| Property | Metric | English | Range |
| Linear CTE (20°C) | 9 μm/m-°C | 5 μin/in-°F | 0 – 100°C |
| Linear CTE (250°C) | 9.4 μm/m-°C | 5.22 μin/in-°F | 20 – 425°C |
| Linear CTE (500°C) | 9.7 μm/m-°C | 5.39 μin/in-°F | 20 – 650°C |
| Specific Heat Capacity | 0.586 J/g-°C | 0.14 BTU/lb-°F | |
| Melting Point (Liquidus) | Min 1636°C; 1674°C | Min 2980°F; 3050°F | |
| Maximum Service Temp (Air) | 350°C | 662°F | Retains mechanical properties |
| Beta Transus Temperature | 982°C | 1800°F |
Standards & Applications
1. Key Specification
- ASTM F136 (biomedical applications)
- UNS R56401
2. Typical Applications
- Medical/Dental: Surgical implants (e.g., orthopedic, dental) due to biocompatibility and fatigue strength.
- Aerospace: Aircraft structural components requiring high toughness and fracture resistance.
- Extreme Environments: Saltwater applications, high-pressure cryogenic vessels (down to -320°C).
- General Engineering: Components needing a balance of strength, lightweight, and corrosion resistance.
Available Product Forms
Bar, billet, extrusions, plate, sheet, strip, and wire.