TC17 / Ti-17 (Ti-5Al-2Sn-2Zr-4Mo-4Cr) Titanium Alloy

TC17 is a Chinese near-β / quasi-β titanium alloy of nominal composition Ti-5Al-2Sn-2Zr-4Mo-4Cr, directly corresponding to the Western Ti-17 (GE) alloy. It offers high strength, excellent fracture toughness, deep hardenability and a wide forging window, and is the standard material for large aero-engine fan and compressor discs up to about 450 °C.

Overview

• Material: TC17 / Ti-17 — Ti-5Al-2Sn-2Zr-4Mo-4Cr near-β titanium
• International equivalent: Ti-17 (GE), China GB TC17
• Available forms: Bar, disc forgings, rings and custom profiles

Chemical Composition (wt%)

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

Physical Properties

Mechanical Properties

Good fracture toughness.

Key Features

• High strength (UTS > 800 MPa, yield around 700 MPa and above);
• Excellent fracture toughness in complex stress states;
• Deep hardenability — suitable for large-section discs;
• Wide forging window and good hot-work flexibility;
• Tunable strength / ductility / toughness balance via heat treatment;
• Good hot strength up to 450 °C.

Fabrication & Heat Treatment

• Melting: typically triple VAR melting for uniform composition and high purity.
• Hot working: forged, rolled or extruded at 850–1000 °C; wide forging window.
• Cold working: moderate cold ductility; intermediate annealing at approx. 650–750 °C.
• Welding: TIG and electron-beam welding after thorough cleaning and suitable shielding.
• Machining: relatively difficult; select appropriate tool material and parameters to control tool wear and surface quality.
• Solution treatment: 800±10 °C / 4 h / water quench (β-forged material); or 840±10 °C / 1 h air cool + 800±10 °C / 4 h water quench (α+β-forged material).
• Ageing: 585–685 °C, typical 630 °C / 8 h, air cool.
• Stress-relief annealing: 480–650 °C / 1–4 h, air or furnace cool; typical 550 °C / 4 h air cool.

Typical Applications

• Aerospace: aero-engine fan and compressor discs and blades; airframe structures and landing gear;
• Shipbuilding: hull structures and propellers;
• Chemical: chemical equipment and piping.

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