High-Strength Aircraft-Grade Titanium Alloys

The current continued growth in the air transportation sector promotes development and application of light but high-strength alloys that help reduce the overall weight and thus increase the aircraft useful load. For this purpose VSMPO developed and promoted titanium alloy VST5553 (VST 55531 – modified alloy with zirconium addition), which is successfully used in mass production of landing gear and airframe components by the major aircraft manufacturers. This alloy is characterized by a high complex of properties (strength of 1240 MPa, elongation of 4-6% and K₁C of 40 MPa) and reduced segregation susceptibility as compared with similar alloys as well as by air hardenability of heavy sections. Despite the achieved results, we keep searching for opportunities to improve the material and its processing methods in order to extend the scope of its application and enhance the material performance.

Key words: titanium alloy, beta stabilization, deformation, heat treatment, high-strength condition, fracture toughness