Titanium (Ti)
Titanium offers the highest strength-to-weight ratio of any structural metal, combined with exceptional corrosion resistance and biocompatibility. Although expensive, it is indispensable in aerospace, medical implants, chemical processing, and high-performance applications where weight savings and corrosion resistance justify the cost.
Properties
- Density
- 4,507 kg/m³
- Melting Point
- 1,668 °C
- Boiling Point
- 3,287 °C
- Thermal Conductivity
- 21.9 W/(m·K)
- Electrical Resistivity
- 4.2 × 10⁻⁷ Ω·m
- Tensile Strength
- 240–1,200 MPa
- Yield Strength
- 170–1,100 MPa
- Hardness
- 70–380 HB
- Elongation
- 10–25%
- Crystal Structure
- HCP (α) / BCC (β)
Common Grades
- Grade 2 (3.7035): Commercially pure titanium, moderate strength. Chemical processing, marine, architecture.
- Grade 5 (Ti-6Al-4V): The workhorse alloy — 60% of all titanium use. Aerospace, medical implants, racing.
- Grade 23 (Ti-6Al-4V ELI): Extra-low interstitial version of Grade 5. Medical implants, cryogenic applications.
- Grade 1 (3.7025): Most ductile commercially pure grade. Deep drawing, explosive cladding, corrosion-resistant lining.
Applications
- Aerospace: Jet engine compressor blades, airframe structures, landing gear, fasteners
- Medical: Hip/knee implants, dental implants, surgical instruments, bone plates and screws
- Chemical Processing: Heat exchangers, reactors, piping in chlor-alkali plants, anodes
- Marine: Submarine hulls, propeller shafts, seawater desalination components
- Sports & Luxury: Golf clubs, bicycle frames, watches, eyeglass frames, exhaust systems
FAQ
Why is titanium so expensive?
Titanium is abundant in Earth's crust but extremely energy-intensive to extract and process. The Kroll process requires multiple reduction steps with magnesium under inert atmosphere. Machining costs are 5–10× higher than steel. These factors combined make finished titanium parts 10–30× more expensive than equivalent steel parts.
Is titanium stronger than steel?
Grade 5 titanium (Ti-6Al-4V) has similar tensile strength to many steels (950 MPa) at only 57% of the weight. On a strength-to-weight basis, titanium is significantly superior. However, ultra-high-strength steels (1,500+ MPa) exceed titanium in absolute strength.
Can titanium be used for medical implants?
Yes, titanium is the gold standard for medical implants due to its biocompatibility — the TiO₂ surface layer is bioinert and promotes osseointegration (bone growth onto the implant). Grade 5 ELI (Ti-6Al-4V Extra Low Interstitial) is the primary implant alloy.
What is the difference between Grade 2 and Grade 5 titanium?
Grade 2 is commercially pure titanium (99.2% Ti) — lower strength (345 MPa yield) but excellent corrosion resistance and formability. Grade 5 (Ti-6Al-4V) is an alpha-beta alloy with 6% Al and 4% V — much higher strength (830 MPa yield) but more expensive and harder to fabricate. Grade 2 dominates chemical processing; Grade 5 dominates aerospace.
Can titanium be 3D printed?
Yes — titanium is one of the most successfully 3D-printed metals. Laser Powder Bed Fusion (LPBF) and Electron Beam Melting (EBM) can produce near-net-shape Ti-6Al-4V parts with mechanical properties meeting aerospace standards. This reduces buy-to-fly ratio from 10:1 (machined) to 1.5:1 (printed), saving significant material cost.