TC21 Damage-Tolerance Alpha-Beta Titanium Alloy

TC21 is a Chinese high-strength, high-toughness α+β titanium alloy of nominal composition Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb-Si. It is engineered for damage tolerance — high strength (≥ 1100 MPa) combined with high fracture toughness (K_IC 70–90 MPa·m^1/2) and low crack growth rate — and is used for critical load-bearing airframe and engine components.

Overview

• Material: TC21 — Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb-Si damage-tolerance titanium
• Available forms: Bar, plate, forgings and custom profiles

Chemical Composition (wt%)

Other elements: each ≤ 0.10 %, total ≤ 0.40 %.

Physical Properties

Mechanical Properties (heat treated)

Low crack growth rate; retains good properties at 400 °C with good elevated-temperature strength and creep resistance.

Key Features

• High strength (≥ 1100 MPa) with good toughness;
• High damage tolerance and low crack growth rate;
• Well-balanced strength, ductility, toughness and crack growth;
• Good hot strength for long-term service below 400 °C;
• Good corrosion resistance and weldability.

Fabrication & Heat Treatment

• Melting: vacuum arc remelting (VAR) for uniform composition and low impurities.
• Hot working: forged, rolled or extruded at 850–1050 °C; β-forging or α+β-forging routes possible.
• Cold working: cold rolled and cold drawn with intermediate annealing at approx. 650–750 °C.
• Welding: TIG, electron-beam and inertia friction welding after thorough cleaning and suitable shielding.
• Machining: carbide tools with controlled speed, feed and depth due to high hardness and strength.
• Annealing: 700–800 °C for 1–2 h, air cool.
• Solution treatment & ageing: solution treat at 880–950 °C then rapid cool; age at 500–600 °C to raise strength. Adjusting solution / ageing parameters tunes the microstructure and properties.

Typical Applications

• Aerospace: wing-joint structures, fuselage-to-landing-gear attachment frames, pylon-engine joints, engine shafts and frames;
• Shipbuilding: high-strength structures and propulsion-system components;
• Energy: high-pressure vessels, piping and towers in petrochemical service; reactor components in nuclear industry.

For detailed datasheets, mill certificates (EN 10204 3.1) or inquiries on specific sizes and tolerances, please contact our sales & engineering team.