ASTM F136 Gr5 Eli Titanium Rod Description
ASTM F136 Gr5 ELI titanium rod is a surgical implant-grade α+β dual-phase titanium alloy rod, complying with ASTM F136 standard for medical implantation (UNS R56401), and it is an extra-low interstitial (ELI) high-strength titanium alloy specially designed and widely applied in high-reliability medical implants and high-precision medical device industries.
Chemical composition: Ti as the balance, Al 5.5-6.75%, V 3.5-4.5%, with ultra-strictly controlled interstitial impurities (Fe ≤ 0.3%, O ≤ 0.2%, C ≤ 0.08%, N ≤ 0.05%, H ≤ 0.015% for bar), guaranteeing superior biocompatibility, minimal metal ion release and long-term in-vivo service safety, which is more suitable for permanent implant scenarios.
Key characteristics: Outstanding strength-to-weight ratio among high-purity medical titanium alloys; excellent tensile strength (≥ 895 MPa) and fatigue resistance (far superior to commercial pure titanium Gr1, Gr2, Gr4 and even standard Gr5), with significantly improved fracture toughness and ductility due to ultra-low interstitial design; moderate formability and favorable machinability for complex implant processing; exceptional corrosion resistance against body fluids and harsh chemical media, as well as reliable structural stability under continuous high-load and human body temperature conditions, effectively reducing stress shielding effect and promoting osseointegration.
Rod form: Available in round rods as the mainstream type, plus square rods and hexagonal rods; manufactured through hot forging, hot rolling, cold drawing and precision machining processes, with strict control of dimensional tolerance and straightness to meet the high precision requirements of medical implants.
Main applications: Medical field (permanent artificial joints, spinal fusion devices, high-strength bone screws, craniomaxillofacial reconstruction implants, dental implants and high-stress surgical implant components); aerospace field (high-reliability lightweight parts, engine fasteners, cryogenic pressure-bearing structural components); industrial field (high-purity corrosion-resistant fittings for precision chemical, marine and extreme working environments requiring ultra-low impurity content).
Technical Specifications
Chemical Specification
|
Elements |
Ti |
O |
Al |
V |
Fe |
C |
N |
H |
Other impurities |
|
Max. content |
Balance |
≤0.20 |
5.5-6.75 |
3.5-4.5 |
≤0.30 |
≤0.08 |
≤0.05 |
≤0.015 |
≤0.40 |
Physical Specification
|
Mechanical properties |
Standard |
Physical properties |
Value |
|
Tensile strength |
≥895 MPa |
Density |
4.51 g/cm³ |
|
Yield strength |
≥825 MPa |
Melt point |
1668 ℃ |
|
Elongation |
≥25% |
|
|
|
Hardness |
290-320 HB |
|
Features & Advantages
- Strict control of interstitial elements such as oxygen, nitrogen and iron, with higher purity and superior biosafety.
- Lower impurity content delivers excellent corrosion resistance for long-term implantation.
- Outstanding toughness and fracture toughness, greatly improving impact resistance and fatigue resistance.
- Moderate strength and hardness, well-matched with human bone modulus to reduce stress shielding effect.
- Uniform internal structure, no brittle failure, excellent processing performance for medical machining.
- Ultra-low allergenicity, effectively lowering the risk of human rejection and inflammatory reactions.
- Excellent surface finishing performance, easy to achieve high-precision polishing and reduce bacterial adhesion.
- Stable comprehensive mechanical properties, longer service life, compliant with high-end medical device standards.
Performance Solution
Problem: Conventional medical titanium contains high interstitial elements, causing trace metal precipitation and slight inflammation after long-term implantation.
Solution: Gr5 ELI strictly controls oxygen, nitrogen and iron with higher purity, avoiding ion precipitation and improving biocompatibility.
Problem: Medical stainless steel and cobalt-chromium alloy have excessive elastic modulus, resulting in stress shielding and bone atrophy.
Solution: Gr5 ELI titanium features bone-matched modulus, effectively reducing bone resorption and postoperative complications.
Problem: Ordinary medical titanium has insufficient toughness, prone to fatigue crack under cyclic loading for dynamic implant applications.
Solution: Low-interstitial composition enhances fracture toughness and fatigue resistance, ensuring long-term structural stability.
Problem: Common medical metals suffer from poor body fluid corrosion resistance and gradual oxidation in physiological environments.
Solution: Gr5 ELI forms a dense passive film, delivering outstanding resistance to body fluid corrosion for permanent implantation.
Problem: Standard titanium has uneven internal structure, leading to surface defects and bacterial adhesion after precision polishing.
Solution: Uniform and dense microstructure enables superior surface finishing, lowering postoperative infection risks.
Problem: Cobalt-chromium and stainless steel are heavy, bringing foreign body sensation and limiting patient daily activity.
Solution: Low-density Gr5 ELI realizes lightweight implantation, reducing physical burden and accelerating recovery.
Problem: General medical titanium with loose impurity control easily causes allergies and tissue rejection.
Solution: Ultra-low interstitial and impurity content greatly reduces sensitization, suitable for sensitive patients and high-standard clinical use.
Problem: Traditional medical metals are brittle at low temperature and difficult to machine, increasing processing loss.
Solution: Gr5 ELI maintains stable toughness and excellent machinability, ideal for high-precision medical device manufacturing.
Application
1. Orthopedic Implants
Used for bone plates, bone screws, intramedullary nails and fixation devices for fracture repair and spinal correction.
2. Spinal Surgery Devices
Applied to spinal rods, pedicle screws and fusion cages, suitable for long-term stable implantation in spinal system.
3. Joint Prosthesis Components
Manufactured for femoral stems, joint connecting parts and auxiliary structural parts of hip, knee and shoulder prostheses.
4. Craniomaxillofacial Implants
Ideal for skull repair plates, facial reconstruction brackets and maxillofacial plastic fixation implants.
5. Dental Implant System
Used for dental implant posts, abutments and oral bone fixation parts, with excellent oral biocompatibility.
6. Trauma Fixation Instruments
Support minimally invasive trauma surgery, including minimally invasive nails, fixing pins and temporary rehabilitation fixation parts.
7. Surgical Instrument Accessories
Applied to high-precision surgical tool handles, connecting shafts and structural parts of orthopedic surgical instruments.
8. Vascular & Orthopedic Minimally Invasive Devices
Used for minimally invasive intervention accessories, soft tissue fixation components and long-term implanted minimally invasive medical parts.