Advanced Technology for Manufacturing High-Strength Titanium Alloy Semi-Finished Products

Introduction:

Titanium alloy plays a special role in the fuselage structure of the aircraft. Now the parts applying titanium alloy contributes 14% of fuselage weight, 36% of engine weight. Nearly all the structural titanium alloys used in Russian aviation and aerospace technology are developed by Russian Institute of Aeronautical Materials.

Titanium alloys with strength of 750-1100 Mpa are widely used in modern load-bearing structures and components. The structural titanium alloys applied in Russian aviation manufacturing industry are widely used in VT6, VT22, VT23 titanium alloys, and advanced high-strength wieldable VT43 titanium alloys designed for space rocket technology. The development of next-generation aircraft and engines has strict requirements on titanium alloys, including the requirement for combining high strength with fracture toughness. The new titanium alloy developed by the project meets these requirements.

High-strength titanium alloy VT22 has been applied in the fuselage and landing gear structures of Russian civil aviation aircraft. It is made into fuselage structural load-bearing parts, welded components(bearing beams, spar, bulkheads, suspension components of the device, ribs, flap guides and leading edge slat rails) made of titanium alloy, and the undercarriage load-bearing parts and components (pillars, bogie rocker landing gear anti-twist arm, brake rocker arm) made of titanium alloy. VT22 alloy has a hard inability of up to 200 mm. In the undercarriage of Il-86, Il-96, Il-76 passenger and transport aircrafts with wide fuselage, more VT22 alloy is applied. The total weight of the landing gear bearing structure made of alloy in the Il-96 passenger aircraft is 900 kg, and the parts made of VT22 alloy in the landing gear structure account for about 30% in total weight. Due to the application of alloys, the weight of the undercarriage of wide-fuselage aircraft landing gear is reduced by 15-20%.

High-strength titanium alloy VT23 is used for manufacturing forgings, stampings, plates, bars and load-bearing parts of molded profiles, also used for manufacturing hot-rolled and cold-rolled pipes, plates, strips, and foils.

The main aim for the development of high-strength structural titanium alloys is to establish a strain and heat treatment process, which can obtain the prescribed microstructure to ensure the best combination of product properties. Another important direction for the development of high-strength structural titanium alloys is to manufacture cost-effective titanium alloys and establish low-energy processing processes.

Technological advantages:

This titanium alloy and titanium alloy semi-finished product manufacturing technology can reduce structural weight by (15-25)%, extend alloy life by (30-40)%, improve alloy reliability by (20-30)%, and reduce alloy cost by (15-25)%, reduce heat treatment power consumption by (40-50)%, reduce pressure processing workload by 15% and cutting processing workload by 20%.

Technological applications:

Aviation

Business plan or market prospects of project cooperation:

Target clients: it is applicable to research institutes, universities and enterprises in the aerospace manufacturing field.

Expected benefits: VT43 alloy is used to manufacture the parts and components of aerospace technology equipment and rocket technology equipment, including gas cylinders, bulkheads, spar beams, stringers, ribs, fasteners, hydraulic accumulators and welding structure of tanks, etc., also used to manufacture large forgings, stampings and plates. Compared with alloys currently used in aircraft, this alloy has higher strength, but has lower density under the conditions of strength and crack resistance. The strength limit of the welded joint of alloy VT43 exceeds 22% of Ti -10V-2FE-3Al (USA), the fracture toughness representation К1сof alloy VT43 exceeds 40% of Ti -10V-2FE-3Al, and the specific strength characteristics (s fracture toughness 20 welding joint/γ) exceeds 20%. The alloy is lower in cost (20% lower), lower in heat treatment power consumption (50% lower), lower in pressure processing workload (20% lower) and cutting processing workload (30% lower).