About the aluminum used for aerospace
According to the Wall Street journal, the world's most luxurious transformed from Kestrel airlines plane, a Boeing 787 air show in wide-bodied aircraft, the aircraft interior has been exposed.Media reports said the plane has been anonymous, Chinese buyers to purchase.
The plane a total $325 million (RMB 2.1 billion), the conversion cost is $100 million!In feeling strong, Chinese buyers at the same time, small make up take you know China's independent research and development manufacturing C919 large passenger aircraft as well as the related issues about the aluminum used for aerospace.
C919 large passenger aircraft is our country with independent intellectual property rights of the first medium-range main commercial aircraft.China will be starting their research and development of large aircraft named C has multiple meanings, first, is China's first letter C, is also China's commercial aircraft co., LTD. English abbreviations COMAC, as well as the significance of large aircraft project goal is to catch up with the A380, and B787, forming one day 'ABC' three pillar, with Airbus (Airbus) and Boeing (Boeing) from ABC and make a form in the international large aircraft manufacturing pattern.The first "9" is the moral of everlasting, "19" represents China's first large aircraft maximum capacity is 190.
And for the C919 large passenger aircraft to give so much hope, also because of its far-reaching influence on the national economy.China's aviation market is huge, the number of large and medium-sized aircraft registered in 2014 2218, almost entirely by Boeing and airbus monopoly.Avic, comac, companies such as Boeing and airbus forecast our country new large and medium-sized passenger aircraft over the next 20 years 5000, worth around $800 billion.
Over the next 20 years China's large passenger demand forecasting (frame)
In 2013, the plane distribution around the world
According to Ascend Fleets data, the current scale of the world's biggest models are mainly single channel trunk airliner.2013 and 2014, the growth of the trunk line aircraft mainly concentrated in the A320 and B737 series, belong to a single-aisle aircraft, guest basic distribution between 120-200.
According to Boeing forecasts, global aircraft over the next 20 years growth is concentrated in the single-aisle aircraft (guest distribution between 90-90), accounting for 70% new fleet size.90-175 seat single-aisle aircraft growth proportion is as high as 35% in Asia, C919 guest distribution is located in the territory.
In the face of such a huge market, the most common form of aerospace "skin" at home and abroad materials for aluminum, more precisely, aluminum used for aerospace, especially noteworthy.
A basic situation, aviation aluminum
Aviation aluminum is a kind of deformation of ultra high strength aluminum alloy, has been widely applied in aviation industry.It has good mechanical and processing properties, good plasticity after solid solution treatment and heat treatment strengthening effect is good, is in commonly 150 ℃ below (or higher) has high strength, good toughness and is the ideal structural material.In addition aviation aluminum light quality, light effect is remarkable, has replaced the steel and to dominate the current aviation materials.The requirements of the aviation equipment for aluminum is higher, is one of the important high-end aluminum application market.
Air superiority in aluminum
Application advantages: aluminum alloy due to its high specific strength, forming and processing performance is good, will also is the main structural materials in the development of the large aircraft.
Application area: wing surface skin, long wing plane girder, edge of wing on the beam bars, web, fuselage stringer, seat slide rail, keel beam and side frame, the fuselage skin, the bottom wall, main floor purlin, etc.
Application: the proportion of the airbus A380-800 biggest in proportion of aluminum alloy material, reached 61%, eads airbus A350-900 aluminum alloy material proportion of 20%, Boeing 787-8 airbus 15% - 15% of aluminum alloy materials.
Second, the large aircraft with aluminum alloy
1, the commonly used aluminum alloy series
In today's world is large aircraft structure with aluminum alloy high strength 2 XXX department (2024, 2224, 2324, 2224, 2524, etc.) and ultra high strength 7 XXX series (7075, 7475, 7050, 7150, 7055, 7085, etc.).
Each department roughly the proportion of aluminum alloy used in civilian airliners
The 2 XXX series aluminum alloy
2 XXX series aluminum alloy is Al - Cu - department of Mg alloy, known as high strength aluminum, aluminum alloy is one of the most versatile structure.Its representative name and chemical composition as listed in table.
The chemical composition of the 2 XXX series aluminum alloy
2 XXX department of the tensile strength of aluminum alloy is 400 ~ 500 MPa, than 7 XXX series aluminum alloy at room temperature strength is low, but the heat resistance and fatigue characteristics, especially the resistance to fatigue crack expansibility is better than 7 XXX series.
7 XXX series aluminum alloy
7 XXX series aluminum alloy belongs to Al - zinc - Mg - Cu alloy, this kind of alloy has high specific strength and rigidity, good corrosion resistance and high toughness, excellent processing performance, has been widely used in large aircraft.
7 XXX series super-high strength aluminum alloy components
2, the development direction of large aircraft aluminum alloy
The research emphasis in the future of aluminium alloy are mainly concentrated in the following aspects: lithium aluminium alloy, aluminium matrix composites and superplastic forming aluminum alloy.
Lithium aluminium alloy
Aluminium lithium alloy is multivariate containing lithium aluminium alloy.Lithium is the lightest metal elements, every 1% increase in aluminum lithium, density can be reduced by 3%, the modulus can be increased by 5%.Lithium aluminium alloy in addition to the light quality, high modulus, and the advantages of high strength, but also has good fatigue resistance and good toughness at low temperature, its strength can be comparable to 2024, 7075 aluminum alloy.In view of this, lithium aluminium alloy has deep air space community love, as a new type of aerospace structural materials, has become the United States, Britain, France, Russia and other developed countries compete to development, the development of hot spots.
At present, has developed a new type of lithium aluminium alloy mainly include 1460 and Weldalite series alloy, high strength, weldable Gao Ren 2097, 2197 alloy, low anisotropy, AF/AF/C - 489 C - 458 alloy, etc.These new lithium aluminium alloy can be referred to as the third generation of lithium aluminium alloy.
The third generation mainly al-li alloy alloy elements
Aluminum matrix composites
Aluminum matrix composite material because of its density is small, than the intensity and rigidity is high, the elastic modulus, good conductive thermal conductivity, high temperature resistance, oxidation resistance, corrosion resistance, preparation of many advantages such as flexible and arouse people's attention, all countries have invested a lot of manpower material resources in research and development, it is the most in metal matrix composites and the main composite materials.Aluminum matrix composites has become a aluminum alloy, even aluminium lithium alloy is an important competitor.Now open hair of aluminum matrix composites are mainly SiC/Al, B/Al, BC/AI, Al2O3 / Al and so on.
The superplastic forming aluminum alloy
The superplastic forming is obtained by thermomechanical treatment of aluminum alloy is less than 10 microns of ultrafine grain, these ultrafine grain of alloy is higher than the melting point and low strain rate to win a superplastic conditions, can be formed out of the traditional method is difficult to obtain the quality of the light, the cost is low, the shape of complex components, and has high forming pressure is small, die life and many other advantages, is a precision forming.
Three, aviation aluminum application analysis on the plane
Aluminium alloy is mainly used as structural materials on the plane, such as: skin, framework, propeller, fuel tank, wall plate and the landing gear strut.
Aerospace aluminum alloy castings
In modern aircraft structures, the use of 1500 ~ 2000 kinds of aluminum castings, according to the different conditions of use of aircraft and parts, mainly use the three basic types of aluminum alloy, high strength aluminum alloy, heat-resistant alloy, corrosion resistant aluminum alloy.
- 1, high strength aluminum alloy is mainly used for aircraft fuselage sections, nacelle, chairs, control system, etc.,
- 2, the heat resistant aluminium alloy parts is mainly used for engine room close to the motor, air exchange system, etc.,
- 3, corrosion resistant performance of the aluminum alloy with high enough, the strength, plasticity, impact toughness, fatigue resistance and weldability are good, mainly has the corrosion resistance, so it can be used in the seaplane.
Aerospace with large extrusion profiles mainly include: the whole ribbed wall board, h girder, beam wing, comb profile, hollow girder profile, etc.Mainly used as the stress of the aircraft, spacecraft and other space aircraft structure parts, and the helicopter special-shaped hollow rotor girder and the runway, etc.
Aluminum alloy thick plate is the modern aerospace industry important structural material, it is widely used in plane frame, the whole wall board, landing gear, skin, etc.
Five, the foreign airlines use aluminum development situation and main on behalf of the company
Foreign airlines use aluminum from 1912 German Hans les, design had the world's first successful use of aluminum metal monoplane, about eight years later, the German first developed a "du" aluminum alloy 2017, and applied to the Junker F13 fuselage structure, from the aviation industry to enter the high-speed development period.
In these 100 years, aluminum alloy in aircraft airframe material dominance has not changed, the hordes of new type aluminum alloy was born to promote the continuous development of the space industry, from the two major aerospace aluminum alloy 2024, 2024 to 2124, 2224, 2324, 7050, 7010, such as the traditional aluminum alloy research, including conducting lithium aluminium alloys, rapid solidification of aluminium alloy, aluminium matrix composites and other non-traditional materials research.
Now the third generation of aluminium lithium alloy is Alcoa's Al - Li - Lp -i (25-100 - mm thick plate) and Al - Li - Tp - 2 (25-100 - mm) alloy is developing, used in the manufacture of 2015-2025 aircraft, their than yield strength than C85T - T76 alloy is higher about 5%, and have very high corrosion resistance.The third generation of lithium aluminum - alloy is in research and development and trial production.
Foreign development and application of aerospace aluminum alloy in the 20th century
Foreign airlines use aluminum suppliers:
Kaiser aluminum and chemical companies in the United States (KaiserAuminum&Chemical co.)
Riley, o company (Aleris)
The Russian aluminium company (party)
Six, domestic air condition and main representative company in aluminum
Aerospace grade aluminum's main rival is Alcoa (Alcoa), connectkentucky aluminum company (Constellium), love excitation (Aleris), Kaiser aluminum and the aluminum company (Kaiser) chemical company.The gap between us and them is very big, especially in the research and development of the studies on the basic theory of alloy gap is bigger, but in terms of hardware, production equipment, we are better than them, because some of China's aviation aluminum professional production line and the project is put into production in recent years, and the projects under construction and planned.Increased investment in science and technology, increase the innovation and research and development to a new level, conditional enterprise cannot be taken for granted.
In China, the development of the aviation aluminum alloy and the application from the 1950 s, was originally intended to cooperate with the need of aircraft maintenance and generic.In the mid - 1980-7075, 2024, 7475, such as alloy research work, but the specifications of the material is far not reached the level of the European and American countries.After the 90 s, about 7 a55, 6 a60, have been developed in high damping aluminium alloy, heat-resistant alloy and aluminium lithium alloy research, but research level is not yet mature, high prices, and foreign advanced technology has a large gap, the plane with thick plate basically rely on imports.
To replace imported and improve product added value, the current domestic at least 10 aluminum production enterprises are focus on aviation with aluminum plate production technology.
Southwest aluminum, south-south aluminum, nanshan aluminum, ming-tai aluminum aluminum companies are committed to domestic large aircraft development and manufacture of air with thick plate.
Domestic air mainly in aluminum company:
Northeast light alloy
Henan ming-tai aluminum
Seven, aviation aluminum why so difficult
In recent years, with the new type aluminum alloy material strength, toughness, demand is higher and higher purity, constantly enhance its capability of material life, to live, innovative new techniques, new technologies are needed to make up the conventional production methods, meet higher performance.Southwest aluminum and other large state-owned enterprises is avic, comac, Boeing and airbus, safran, antonov well-known both at home and abroad aviation companies such as important material supplier.With rich resources, based on distributed in various secondary enterprise flow of state-level enterprise technology center, postdoctoral scientific research workstations, such as research and development platform, strong technical force to strengthen organization of major key and forward-looking technology research and development, complete aviation aluminum r&d manufacturing.
And private enterprises such as ming-tai aluminum, while relying on the rich production experience and practice of scientific research personnel, for air in the early stage of the aluminum has a lot of achievements in research and development, but the lack of large scale of actual combat experience, to know, to research on the properties of materials and put into use has become a big challenge.This requires enterprises, each process, each parameter, every details of the control, accurate to seconds each solution to through a lot of practice, scientific research and production practice.Investment is large, the high quality demand of engineering technology, universal existence "study, and research, while dry" problem.
Through continuous innovation, captured a ming-tai aluminum a key technique, developed in succession such as 2, 7 the third generation of aviation aluminum alloy material, breaking the foreign technology blockade, has paved the way for the enterprise to the transformation of high precision aluminum manufacturing.