Effect Of Heat Treatment Process On Microstructure And Properties Of TC18 Titanium Alloy Profiles

TC18 titanium alloy is a high-strength titanium alloy developed by the All-Russian Institute of Aviation Materials in Russia in the 1960s, and its corresponding Russian grade is BT22. The nominal composition is Ti-5Al-5Mo-5V-1Cr-1Fe, and the Al equivalent under the nominal composition is 5.0%, and the Mo equivalent is 11.76%. This alloy belongs to the transitional α+β alloy, with high strength, good elongation and cross-sectional shrinkage, high impact resistance, hardenability and welding performance. It is mainly used as a structural part in the aviation field. The maximum long-term working temperature of the alloy is 400℃. The research on titanium alloy profiles can be traced back to the 1950s. Western countries represented by Russia and the United States mainly applied it in the aviation field. They developed various titanium alloy profiles such as profiles for components and secondary load-bearing frames for aircraft engines, fighter jets and other equipment, which pioneered the large-scale application of titanium alloy profiles in this field. After decades of development, titanium alloy profiles have been widely used in aerospace, military fighters, civil airliners, etc., covering low-strength, medium-strength and high-strength levels, and developed titanium alloy profiles with various cross-sections including "T", "L", "U", "H", "Z", "Y" and "J" shapes. At present, the mainstream method of titanium alloy profile production is hot extrusion, and then surface finishing or machining into the final shape according to actual needs.