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Aircraft manufacturing

Titanium

AIRCRAFT INDUSTRY REMAINS THE FIRST AND THE MAJOR TITANIUM CONSUMER

Material requirements for aircraft building:
1.small weight
2.high specific strength
3.heat resistance
4.fatigue load resistance
5.crack resistance
6.corrosion resistance

Aluminium was widely used in subsonic aircraft. Aerotechnics of supersonic speeds faced with elevated temperatures of the aircraft skin for which aluminium can not be applied due to low heat resistance. Structural materials reliably operating in complicated combination of force and temperature fields under the influence of corrosive media, radiation and high pressures were required. Titanium and its alloys meet this requirement.

Currently a greater amount of titanium is incorporated in to aircraft. This is connected with the fact that the share of the composite materials with which aluminium intensively interacts and corrodes in the new airplanes is being increased. Titanium is not subjected to these processes and results in increasing the life of components.

Three major trends of titanium application for aircraft building:
1.fabrication of items of complex space configuration:
- hatch and door edging where moisture is likely to be accumulated (high corrosion resistance of titanium is used)
- skins which are affected by engine combustion product flow, flame preventing fire safety-proof membranes (high temperature of melting and chemical inactivity of titanium is used)
- thin-walled lead pipes of air system (minimum thermal titanium extension ratio compared to all other metals is used)
- floor decking of the cargo cabin (high strength and hardness is used)
2.fabrication of designated high-loaded assemblies and units
- landing gear
- fastening elements (brackets) of the wing
- hydrocylinders
3.engine part manufacture (see next section).

The following is manufactured from titanium alloys for aircraft applications:
Ailerons, panel and swivel wing assemblies, spar walls, panels, brackets, steering wheels, wedge meshes, air intake ducts, lead pipes, frames, leading edge flaps and flaps, hydraulic systems, fasteners and a number of other parts.

The percentage of titanium contained in the air frame:
Boeing -707 v less than 0,5 %, юN-24 v 0,48 %, рU-154 - 2 %, Boeing-777 v 8.5 %, рU-334 v 8,7 %, юN-148 v up to 10 %, IL-76 and IL-76р - 12 % of the air frame weight.

VSMPO-AVISMA Corporation delivers titanium semi-finished products designated for aircraft parts manufacture to its foreign and domestic customers:
- landing gear forgings
- plate, sheet, bar and billet for manufacture of swivel assemblies, guide rails, flaps, panels, spars, fastening elements
- solid structures of die-forged forgings for electrohydraulic system.

 

TITANIUM ALLOY PRODUCTS OF JSC VSMPO-AVISMA CORPORATION
FOR ENGINE APPLICATION

JSC VSMPO-AVISMA Corporation is the world largest integrated producer of all types of semi-finished products from titanium alloys for lots of industrial branches applications: billet, forging, electrode, plate, sheet, bar, tube.

Products Quality Management System (QMS) of the Corporation was accepted practically by all the major world aircraft and engine-building companies such as: Boeing, EADS, General Electric, Pratt&Whitney, Rolls-Royce, SNECMA, Goodrich and others. The number of international certificates of QMS, specific types of products as well as manufacturing processes, inspection and test methods is constantly maintained, updated and increased.

The major production trends of titanium semi-finished products are as follows: manufacture of disk and blade for fans and compressors, forgings and casing stock. As of today a great amount of products for aircraft engines and gas turbine plants (GTP), gas-compressor units, power plants as well as ship GTP have been mastered by VSMPO-AVISMA Corporation. On an annual basis the volume of deliveries and stock range supplied to domestic and foreign facilities is increased. Currently VSMPO-AVISMA Corporation takes part not only in all domestic programs aimed at development of new engines and modernization of the production ones, but also in plenty of joint and international projects.

As is well known, strict requirements for products and materials of aircraft designation are stipulated by both foreign users and domestic engine-building companies.

In order to maintain a high production level a lot of investments for reconstruction of the existing equipment and purchasing a new one are regularly made by VSMPO-AVISMA Corporation. For example, forging equipment, melting and heating furnaces controls have been computer aided. Cold hearth plasma furnace, multizone UST unit of billet and disk have been installed and FPI area has been constructed.

Currently, in the world, there is not a single new project with titanium alloy materials involved without VSMPO-AVISMA Corporation participation. In Russia and in CIS countries one could not find a single aircraft engine, aircraft or a helicopter, which would not incorporate
titanium of VSMPO-AVISMA Corporation.

Aluminium

Aluminium in Aircraft manufacturing

Wide application of aluminium in industry is mainly explained by its large natural resources as well as a set of chemical, physical and mechanical properties.

Aluminium is one of the most widespread metals, regarding its content in the earth's crust (~8 %).

Among one of aluminium's advantages shall be considered its low density (2.7 g/cm3), relatively high strength properties, good thermal and electric conductivity, technological effectiveness, high corrosion resistance. Due to combination of these properties aluminium is considered to be one of the most important engineering materials.

Aluminium alloys are the main structural material in aircraft industry at the present-day stage of subsonic and supersonic aircraft development. Alloys of 2ххх, Зххх, 5ххх, 6ххх and 7ххх series are widely used for aircraft industry in the USA. 2ххх series is recommended for work at high operating temperatures and with increased values of fracture toughness ratio. Alloys of 7ххх series are recommended for operation of significantly loaded parts at lower temperatures and for parts with high corrosion resistance under stress. Alloys of Зххх, 5ххх and 6xxx series are used for low-loaded assemblies They are also used in hydraulic, oil and fuel systems.

Al-Zn-Mg-Cu high-strength aluminium alloys hardened by heat treatment and Al-Mg-Cu average- and high-strength aluminium alloys are successfully used for aircraft equipment production in Russia. They are structural material for skin and inner set of airframe components (body, wing, keel, etc.).

1420 alloy pertaining to Al-Zn-Mg system is used for airliner welded body design. Usage of aluminium-magnesium corrosion-resistant welded alloys (AМг5, АМг6) and Al-Zn-Mg alloys (1915, В92, 1420) is provided for hydroplane production.

Aluminium welded alloys have undeniable advantage when designing space technology items. High strength-to-weight ratio, stiffness-to-weight ratio of the material provided for manufacture of missile tanks, intertank and nose parts with high directional stability. Among the advantages of aluminium alloys (2219 and others) is their operationability under cryogenic temperatures in contact with liquid oxygen, hydrogen and helium. These alloys are capable of the so-called cryogenic hardening, i.e. strength and ductility increase simultaneously with the decrease of temperature.

1460 alloy pertains to Al-Cu-Li system and is most promising for design and manufacture of tank structures with regard to cryogenic type of fuel - compressed oxygen, hydrogen or natural gas.