Overview
Grade 23 Titanium, also known as Ti-6Al-4V ELI (Extra Low Interstitial), is a premium medical-grade titanium alloy derived from Grade 5 titanium. By reducing the oxygen, nitrogen, carbon, and iron content, Grade 23 provides superior fracture toughness, fatigue resistance, ductility, biocompatibility, and crack propagation resistance compared with standard Grade 5 titanium.
Grade 23 is widely recognized as the preferred titanium alloy for medical implants, surgical devices, aerospace components, and high-reliability engineering applications where mechanical performance and long-term durability are critical.
Grade 23 titanium is widely used in:
- Orthopedic Implants
- Dental Implants
- Surgical Instruments
- Aerospace Components
- Medical Devices
- Bone Fixation Systems
- High-Performance Fasteners
- Precision Engineering Components
Because of its excellent biocompatibility and fatigue strength, Grade 23 is one of the most commonly specified implant-grade titanium alloys worldwide.
Material Specification
| Property | Value |
|---|---|
| Material Designation | Grade 23 Titanium |
| Alloy Name | Ti-6Al-4V ELI |
| UNS Number | R56401 |
| ASTM Standard | ASTM F136 / ASTM B348 / ASTM B265 |
| Material Family | Alpha-Beta Titanium Alloy |
| Density | 4.43 g/cm³ |
| Magnetic Property | Non-Magnetic |
| Typical Supply Condition | Annealed |
| Standard Forms | Bar, Rod, Sheet, Plate, Wire, Tube, Forgings |
Chemical Composition
| Element | Content (%) |
|---|---|
| Titanium (Ti) | Balance |
| Aluminum (Al) | 5.5–6.5 |
| Vanadium (V) | 3.5–4.5 |
| Iron (Fe) | ≤0.25 |
| Oxygen (O) | ≤0.13 |
| Carbon (C) | ≤0.08 |
| Nitrogen (N) | ≤0.05 |
| Hydrogen (H) | ≤0.0125 |
The reduced interstitial content improves ductility, toughness, and fatigue performance compared with Grade 5.
Mechanical Properties
Annealed Condition
| Property | Value |
|---|---|
| Tensile Strength | ≥860 MPa |
| Yield Strength | ≥795 MPa |
| Elongation | ≥10% |
| Hardness | 300–360 HB |
| Elastic Modulus | 114 GPa |
Implant Grade Performance
| Property | Value |
|---|---|
| Fatigue Strength | Excellent |
| Fracture Toughness | Outstanding |
| Crack Resistance | Outstanding |
| Biocompatibility | Excellent |
Physical Properties
| Property | Value |
|---|---|
| Density | 4.43 g/cm³ |
| Melting Point | 1604–1660°C |
| Thermal Conductivity | 6.7 W/m·K |
| Electrical Conductivity | 1% IACS |
| Electrical Resistivity | 1.72 μΩ·m |
| Thermal Expansion Coefficient | 8.6 × 10⁻⁶/K |
| Specific Heat Capacity | 560 J/kg·K |
Strength-to-Weight Ratio
| Material | Density (g/cm³) | Tensile Strength |
|---|---|---|
| Grade 23 Titanium | 4.43 | 860 MPa |
| Grade 5 Titanium | 4.43 | 895 MPa |
| Grade 4 Titanium | 4.51 | 550 MPa |
| 316L Stainless Steel | 8.00 | 485 MPa |
Although slightly lower in strength than Grade 5, Grade 23 offers significantly better toughness and fatigue resistance.
Corrosion Resistance
| Environment | Performance |
|---|---|
| Body Fluids | Excellent |
| Fresh Water | Excellent |
| Salt Water | Excellent |
| Marine Atmosphere | Excellent |
| Chloride Solutions | Excellent |
| Chemical Processing | Very Good |
Grade 23 develops a highly stable titanium oxide layer that provides excellent corrosion resistance in biological and industrial environments.
Recommended surface treatments:
- Passivation
- Anodizing
- Electropolishing
- Medical Surface Finishing
- Precision Polishing
Biocompatibility
| Property | Rating |
|---|---|
| Tissue Compatibility | Excellent |
| Osseointegration | Outstanding |
| Toxicity | None |
| Implant Acceptance | Excellent |
Grade 23 is one of the most widely used implant-grade materials in orthopedic and dental applications.
Fatigue Resistance
| Property | Performance |
|---|---|
| Fatigue Strength | Outstanding |
| Cyclic Loading Resistance | Outstanding |
| Crack Growth Resistance | Outstanding |
| Long-Term Reliability | Excellent |
The ELI chemistry provides superior fatigue life compared with standard Grade 5 titanium.
Weldability
| Welding Process | Rating |
|---|---|
| TIG Welding | Excellent |
| MIG Welding | Good |
| Resistance Welding | Excellent |
| Laser Welding | Excellent |
Proper inert gas shielding is required during welding.
Machinability
| Process | Rating |
|---|---|
| CNC Turning | Moderate |
| CNC Milling | Moderate |
| Drilling | Moderate |
| Grinding | Good |
| EDM Machining | Excellent |
Machinability Comparison
| Material | Machinability |
|---|---|
| Aluminum 6061 | Excellent |
| Grade 23 Titanium | Moderate |
| Grade 5 Titanium | Moderate |
| Inconel 718 | Difficult |
Grade 23 machining characteristics are very similar to Grade 5 titanium.
Heat Treatment
Stress Relief
| Parameter | Value |
|---|---|
| Temperature | 480–650°C |
| Cooling Method | Air Cool |
Annealing
| Parameter | Value |
|---|---|
| Temperature | 700–800°C |
| Cooling Method | Air Cool |
Heat Treatability
| Property | Performance |
|---|---|
| Heat Treat Hardening | Excellent |
| Structural Stability | Excellent |
| Fatigue Enhancement | Excellent |
International Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| ASTM | Grade 23 |
| ASTM F136 | Ti-6Al-4V ELI |
| UNS | R56401 |
| ISO | Ti-6Al-4V ELI |
| DIN (Germany) | 3.7165 ELI |
| EN (Europe) | TiAl6V4 ELI |
| GB/T (China) | TC4 ELI |
| JIS (Japan) | Ti-6Al-4V ELI |
Available Forms
| Product Type | Availability |
|---|---|
| Round Bar | Yes |
| Sheet | Yes |
| Plate | Yes |
| Tube | Yes |
| Wire | Yes |
| Forgings | Yes |
| Medical Implant Stock | Yes |
Typical Applications
Medical Industry
- Orthopedic Implants
- Hip Replacements
- Knee Implants
- Dental Implants
- Bone Screws
- Spinal Fixation Devices
Surgical Equipment
- Surgical Instruments
- Implant Tools
- Medical Fasteners
Aerospace Industry
- Structural Components
- Fasteners
- High-Reliability Components
- Fatigue-Critical Parts
Marine Industry
- Corrosion-Resistant Hardware
- Offshore Equipment
- Precision Components
High-Tech Manufacturing
- Precision Components
- High-Performance Fasteners
- Specialty Engineering Parts
Manufacturing Characteristics
| Manufacturing Process | Rating |
|---|---|
| CNC Machining | Good |
| Medical Machining | Excellent |
| Forging | Excellent |
| Welding | Excellent |
| Additive Manufacturing | Outstanding |
| Polishing | Excellent |
Advantages
Exceptional Biocompatibility
Industry-standard material for medical implants.
Outstanding Fatigue Resistance
Superior fatigue life compared with Grade 5.
Excellent Fracture Toughness
Better crack resistance and reliability.
High Strength-to-Weight Ratio
Provides excellent mechanical performance with low weight.
Excellent Corrosion Resistance
Ideal for biological and marine environments.
Non-Magnetic
Suitable for MRI-compatible medical devices.
Limitations
Higher Cost Than Grade 5
Additional processing and purity requirements increase cost.
More Difficult Machining Than Stainless Steel
Requires specialized tooling and cutting strategies.
Lower Thermal Conductivity
Poor heat transfer characteristics.
Limited Availability
Not as widely stocked as Grade 5 titanium.
Comparison with Other Titanium Grades
| Property | Grade 23 | Grade 5 | Grade 9 | Grade 2 |
|---|---|---|---|---|
| Strength | High | Highest | Moderate | Moderate |
| Fatigue Resistance | Outstanding | Excellent | Excellent | Good |
| Fracture Toughness | Outstanding | Good | Good | Moderate |
| Biocompatibility | Outstanding | Good | Good | Excellent |
| Medical Applications | Preferred | Limited | Limited | Moderate |
Comparison with Common Implant Materials
| Material | Strength | Biocompatibility | Corrosion Resistance |
|---|---|---|---|
| Grade 23 Titanium | Excellent | Outstanding | Excellent |
| Grade 5 Titanium | Excellent | Good | Excellent |
| 316LVM Stainless Steel | Good | Good | Good |
| CoCrMo Alloy | Excellent | Good | Excellent |
Available Surface Finishes
Raw Finishes
- Mill Finish
- Annealed Finish
- Pickled Finish
Functional Finishes
- Precision Machined Finish
- Polished Finish
- Medical Surface Finish
Specialty Finishes
- Anodized Finish
- Electropolished Finish
- Implant Grade Finish
Frequently Asked Questions (FAQ)
What is Grade 23 titanium?
Grade 23 is an Extra Low Interstitial (ELI) version of Ti-6Al-4V designed for medical implants and high-reliability applications.
What is Grade 23 titanium used for?
Typical applications include:
- Orthopedic Implants
- Dental Implants
- Surgical Instruments
- Aerospace Components
- Medical Devices
What is the equivalent material to Grade 23 titanium?
Common equivalents include:
- Ti-6Al-4V ELI
- ASTM F136
- UNS R56401
- TC4 ELI
What is the difference between Grade 5 and Grade 23 titanium?
| Property | Grade 5 | Grade 23 |
|---|---|---|
| Strength | Slightly Higher | Slightly Lower |
| Fatigue Resistance | Excellent | Better |
| Fracture Toughness | Good | Outstanding |
| Medical Use | Limited | Preferred |
Is Grade 23 titanium biocompatible?
Yes. It is one of the most widely used implant-grade titanium alloys in the medical industry.
Can Grade 23 titanium be welded?
Yes. Grade 23 offers excellent weldability when proper shielding techniques are used.
Why choose Grade 23 titanium?
Because it combines:
- Excellent Biocompatibility
- Outstanding Fatigue Resistance
- High Strength
- Excellent Corrosion Resistance
- Superior Fracture Toughness
Is Grade 23 suitable for medical implants?
Yes. Grade 23 is one of the leading materials used for orthopedic and dental implants worldwide.
Does GCNOV provide custom manufacturing services for Grade 23 titanium?
Yes. GCNOV provides:
- CNC Machining
- Medical Component Manufacturing
- Titanium Forging
- Precision Welding
- Surface Finishing
- Prototype Development
- Low-Volume Production
- Mass Production