Aircraft updating speed is slower than electronic equipment, but it is also quite fast. The development trend of aircraft is high speed, long service life, safety and reliability, low structural mass coefficient, low cost, low maintenance workload and comprehensive stealth. The aluminium industry must provide new materials for aircraft updates and surpass previous generations. At present, the development of aircraft aluminum alloy plate sheet
is mainly around strength, stiffness, heat resistance, long service life, low cost manufacturing and forming technology.
1. Strength and stiffness
Improving the strength and stiffness of materials is an eternal topic. At present, the main measures taken by material workers are: a. Increasing the content of alloying elements, but increasing the content of alloying elements will bring a series of difficulties to the melting, casting, processing and forming of alloys, which may have adverse effects on the corrosion resistance, fracture toughness and fatigue properties of alloys. B. Microalloying of the alloy is considered one of the most desirable and effective measures. C. Heat treatment is mainly to carry out multi-stage, partial solid solution and solution aging treatment, to improve the strength and properties of the alloy as far as possible under the premise of meeting the requirements of corrosion resistance. D. Aluminum alloy ingots were prepared by spraying liner technology and powder metallurgy, a new manufacturing technology.
2. Heat resistance
The aerodynamic heating and overload problems of aircraft will become more prominent with the increase of flight speed. At present, the research and development of aluminium Aeronautics in Chalco Aluminum mainly focuses on: a. Adding a small amount of Fe and Ni to the low alloyed 2*** series alloy, such as the newly developed 2650 alloy, is a heat-resistant alloy, which can be used to manufacture the skin of supersonic aircraft. B. Adding a small amount of special alloying element Ag C to the traditional 2*** alloy. Great progress has been made in the preparation of heat-resistant alloys by powder metallurgy and spray deposition, which may become the main technology for preparing high temperature aircraft aluminum alloy plate sheet
in the future.
3. Reliability and long-term service
Aircraft must have high reliability and as long as possible service life. This purpose requires materials to have high fracture toughness, fatigue strength and corrosion resistance. Chalco Aluminum has done a lot of work in this area and achieved remarkable achievements: a. Improving the purity of alloys, i.e. reducing the content of iron and silicon inherent in aluminium magazines, now almost all aircraft aluminum alloy plates sheets
have corresponding. High-purity alloys, first made of 2024 and 7075 high-purity alloys. B. Starting from the data provided by the phase diagram, the alloy composition should be strictly controlled to reduce the number of insoluble and excess phases. C. Heat treatment has a significant effect on the properties of wrought aluminium alloys.
4. Reducing quality
There are two meanings to reduce the mass: one is to reduce the absolute mass of the aluminum alloy itself; the other is to improve the specific strength of the alloy. Common measures to reduce the quality are: a. Increasing the specific strength of alloys, developing high strength alloys, and producing some high-component alloys by spray deposition. B. The density of lithium is the lightest among the alloying elements of Al. When 1% Li is added to Al, the density of Al decreases by about 3%, while its positive elastic modulus increases by about 5%.
5. Development of new alloys adapted to new forming technologies
At present, two main tasks of Chalco Aluminum research and development are: a. Aging and superplastic forming. B. Vigorously develop aluminium alloy with good weldability.