Titanium Gr23

Titanium Grade 23 is an extra low interstitial (ELI) version of Titanium Grade 5, developed for medical implants, high purity applications and cryogenic environments. Titanium Grade 23 is very similar to Grade 5 except that Grade 23 has less oxygen, nitrogen and iron. The combination of biocompatibility, ductility and high strength makes it ideal for critical applications where material purity and toughness are crucial.

Recommended filler material for welding: Ti-6Al-4V ELI under shielding gas such as argon.

General material description:
Type: α+β titanium alloy (~6% Al, ~4% V) with extra low oxygen, carbon, nitrogen and iron content
Structure: Mixed alpha + beta structure (HCP + BCC)
Developed for: Medical implants and applications requiring extreme toughness and low interstitial contamination
Alternative names: Titanium Grade 23, Ti-6Al-4V ELI, UNS R56401, ASTM F136 (implants), ISO 5832-3

Key benefits:
High strength (~900 MPa) while being more tougher and more malleable than Grade 5
Exceptional biocompatibility – used in orthopedic and dental implants
Extra low oxygen content – improved toughness, even at cryogenic temperatures
Good corrosion resistance in body fluids and marine environments
Very good weldability and good surface finish after machining

Disadvantages / Limitations:
More expensive than Grade 5 – due to controlled chemical purity
Not optimized for high temperature (>450°C)
Poorer malleability than pure titanium (Grade 2, 4) – requires hot working for complex shapes

Applications by industry and value:
Medical technology: Hip, knee, spine implants, dental implants – biocompatibility + strength
Aviation / Defense: Structural components with requirements for toughness and low defect level
Cryotechnology: Components that must function at very low temperatures – toughness maintained
Food / Cleanroom: Low ion emission, good corrosion stability
High technology: Semiconductor equipment – material purity + corrosion resistance

General corrosion description:
Dense and self-healing oxide film – very resistant to body fluids, salt solutions and acids
Good resistance to stress corrosion cracking and pitting
Not sensitive to hydrogen-induced embrittlement during normal operation

Corrosion environments where the material works well:
Body fluids (blood, saliva, interstitial fluid)
Physiological salt solutions and sea water
Mild acids, oxidizing chemicals
Water vapor, humid environments with sterilization requirements

Corrosion environments where the material should be avoided:
Hydrofluoric acid (HF)
Reducing acids at high temperature without oxygen supply
Static, acidic chloride environments with low passivity

Technical material properties (annealed condition, ASTM F136):
Property (Typical value)
Yield strength (0.2%): ~795–860 MPa
Tensile strength: ~860–950 MPa
Elongation at break: ~14–15%
Density: ~4.43 g/cm³
Modulus of elasticity: ~114 GPa
Thermal conductivity: ~6.7 W/m·K
Using temperature: Rec. ≤ 400°C (short-term up to ~540°C)
Weldability: Very good – requires shielding gas (argon)
Machinability: Good – but requires sharp tools and cooling