TIMET TIMETAL® 551 (Ti-4Al-4Mo-4Sn-0.5Si) Titanium Alloy;

High-Strength Forging AlloyIndustry Specifications: UK Aerospace Specifications BS TA.38, 39, 40, 41, 42.Features: TIMETAL 551 has high strength and is creep resistant up to 400°C. It has a similar composition to TIMETAL 550, apart from an increase in tin content, which gives increased strength at room and elevated temperatures. This is one of the strongest of the commercially available titanium alloys, with room temperature strengths ranging form 1250 to 1400 MPa. Typical applications include airframe structural forgings and machined parts such as undercarriage components, mounting brackets and pump casing where strength is required at low weight; and gas-turbine engine components. The alloy is also suitable for general engineering applications such as steam-turbine blades, axial and radial compressor parts, connecting rods, and other high-speed rotating and reciprocating components. It is nonmagnetic.Typical heat treatment for this alloy: Solution heat treatment: 900°C for 1 hr, air cool. Ageing heat treatment: 500°C for 24 hrs, air cool.Data provided by TIMET.