TC18 (Ti-5Al-5Mo-5V-1Cr-1Fe) Near-Beta Titanium Alloy

TC18 is a highly alloyed, high-strength near-β titanium alloy of nominal composition Ti-5Al-5Mo-5V-1Cr-1Fe (Russian VT22-type). It combines very high strength (≥ 1300 MPa after strengthening), good toughness, deep hardenability (up to approx. 250 mm section) and good corrosion resistance, and is the Chinese choice for large load-bearing airframe and landing-gear structures — replacing high-strength steels or Ti-6Al-4V for 15–20 % weight savings.

Overview

• Material: TC18 — Ti-5Al-5Mo-5V-1Cr-1Fe near-β titanium
• Approx. equivalent: Russian VT22-type
• Available forms: Bar, plate, forgings and custom profiles

Chemical Composition (wt%)

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

Physical Properties

Mechanical Properties

Retains good properties at 400 °C. Deep hardenability up to approx. 250 mm section.

Key Features

• Very high strength with good toughness and impact resistance;
• Excellent deep hardenability (section up to approx. 250 mm);
• Good weldability (improved after annealing);
• Excellent corrosion resistance thanks to high Mo content;
• Good hot workability for precision forging.

Fabrication & Heat Treatment

• Melting: vacuum arc remelting (VAR) for uniform composition and low impurities.
• Hot working: forged, rolled or extruded at 850–1000 °C; large bars use multi-cycle "high-low-high" forging schedules.
• Cold working: cold rolled and cold drawn with intermediate annealing at approx. 650–750 °C.
• Welding: TIG and electron-beam welding after thorough cleaning; best after annealing.
• Machining: use high-speed tungsten or multi-coated carbide tools, optimised geometry and generous coolant.
• Annealing: relieves work-hardening stress and refines structure.
• Double annealing: 830 °C / 1–4 h furnace cool to 750 °C / 1–4 h air cool, then 570 °C / 4 h, air cool — good strength with improved fracture toughness and high-temperature stability.
• Solution treatment & ageing: solution treat to dissolve alloy elements, then age to precipitate strengthening phases.

Typical Applications

• Aerospace: airframe, landing gear and engine load-bearing structures — replacing high-strength steel or Ti-6Al-4V for 15–20 % weight saving;
• Defence: key weapon-system components;
• Marine: offshore-platform structures and seawater piping;
• High-end manufacturing: equipment and parts requiring high strength and corrosion resistance.

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