Titanium

Summary

Titanium is a low-density metal that forms a thin passive oxide film, supplied as commercially pure grades and alloys such as Ti-6Al-4V. It resists sea water and chlorine and is stronger than 6061-T6 aluminum, but it costs far more than common architectural metals.

Cols

Image

CP titanium: commercially pure, unalloyed grades (Grade 1 to 4)
Grade 5 / Ti-6Al-4V: alloy with about 6 percent aluminum and 4 percent vanadium
Grade 23: extra-low-interstitial (ELI) version of Ti-6Al-4V
Kroll process: magnesium reduction of titanium tetrachloride to titanium sponge
UNS R50250 / R50400: Grade 1 / Grade 2

History and demand

Invention

1910: Matthew Hunter produced 99.9 percent pure titanium
1932: William Kroll produced titanium with calcium, then refined the process with magnesium about 1940; the Kroll process remains the main commercial route

Sourcing

2024 world titanium sponge output was about 320,000 metric tons; China about 220,000 tons (69 percent), Japan 55,000 tons (17 percent)
United States sponge imports in 2025 through July came from Japan (73 percent), Kazakhstan (13 percent), and Saudi Arabia (13 percent); no sponge has been produced in the US since 2024 (USGS)

Composition and production

Manufacturing process

Ilmenite and rutile ore reduced to sponge by the Kroll process, then melted and rolled

Product forms

Strip, sheet, and plate (ASTM B265), bar, and powder

Grades and types

Grade 1 and Grade 2: unalloyed titanium; Grade 2 is the common architectural sheet grade
Grade 2H: Grade 2 with 58 ksi minimum tensile strength
Grade 5: Ti-6Al-4V alloy
Grade 23: ELI variant of Ti-6Al-4V
Beta C: alloy with tensile strength above 1,400 MPa (203 ksi)

Properties

Physical

Density: 4.502 g/cm³ (281 lb/ft³) at 68°F
Melting point: 1,668°C (3,034°F)

Mechanical

Tensile strength (99.2 percent CP): about 434 MPa (63 ksi)
Modulus: 120 GPa (17,400 ksi)
More than twice as strong as 6061-T6 aluminum at about 60 percent greater density
Strength decreases above 430°C (806°F)

Thermal and moisture

Thermal conductivity: 21.9 W/(m·K), about 152 Btu·in./(h·ft²·°F)
Thermal expansion: 9.68 × 10⁻⁶/K at 68°F, about 5.4 × 10⁻⁶ in./in./°F

Durability

Passive oxide film 1 to 2 nm thick, growing to about 25 nm over four years
Resists sea water, aqua regia, and chlorine
Dissolves in dilute hydrofluoric acid and in hot hydrochloric and sulfuric acid

Standards

Material specifications

ASTM B265: titanium and titanium alloy strip, sheet, and plate (B265-25)

Uses in buildings

Building elements

Metal Wall Panels: sheet cladding and facade elements
Standing Seam Metal Roofing: roofing sheet

Pros and cons

Pros

Passive oxide film resists sea water and chlorine
High strength relative to weight

Cons

High market value
Attacked by hydrofluoric acid and hot hydrochloric or sulfuric acid
Strength falls above 430°C

Sustainability

Recycled content and end of life

Scrap titanium can be recycled into powder

Manufacturing and cost

Main manufacturers and suppliers

Trade association: International Titanium Association.

Sources

Wikipedia: Titanium, https://en.wikipedia.org/wiki/Titanium
ASTM: B265 listing, https://store.astm.org/b0265-02.html
Performance Titanium Group: ASTM B265 grade 2, https://performancetitanium.com/astm-b265-grade-2/
Wikimedia Commons: Titanium products.jpg, photo by Mark Fergus (CC BY 3.0), https://commons.wikimedia.org/wiki/File:Titanium_products.jpg
USGS: Mineral Commodity Summaries 2026, titanium, https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf