Due to the low density of aluminum, it is only 1/3 of that of steel; it is rich in resources; its price is moderate; it can be formed and processed well; its strength is not low; it is also non-magnetic; its weldability is also good, especially with some friction stir welding ( FSW) performance; strong corrosion resistance; no low-temperature brittleness, its strength and plasticity (elongation, compression rate, toughness) rises uniformly with the decrease of temperature, can be below -200°C or lower Work; high temperature performance is acceptable, but can not work longer than 180 °C; recyclability is strong, in the current application of structural metal materials is a high regeneration recovery rate; and so on.
General military use, patrol, smuggling, narcotics, and net inspection boats account for about 40% of the total mass. To reduce the hull mass, choosing aluminum is the current best choice. In the case of strength equal to that of steel, the quality of the aluminum alloy structure is about 35% to 52% of the low carbon steel. When the rigidity is equal to the steel, the quality of the aluminum structure is about 50% of the steel. Thus, in order to reduce the quality of ships, aluminum is the preferred material for manufacturing hulls, superstructures, and other warehouse surface appliances, and is particularly preferred for the manufacture of gliding boats, hydrofoil boats, hovercrafts, and pelting boats. Because their quality is particularly sensitive to speed, it means that reducing the hull mass is extremely effective in improving speed.
In order to improve passengers' living conditions for passenger ships, the living area must be expanded and the superstructure must be increased, and the stability of the ship may be reduced. However, widening the width of the ship can improve the stability of the ship, but the speed will drop. The use of aluminum alloy for the manufacture of superstructures can effectively resolve this contradiction, that is, under the premise of maintaining sufficient stability, expand the superstructure to achieve better living conditions. purpose.
The use of aluminum to manufacture ship hulls and superstructures can increase the cargo volume or increase the speed of the ship, thereby reducing transportation costs. Due to the non-magnetic properties of aluminum, it is a superior material for the manufacture of minesweepers and special-purpose vessels and devices.
Since aluminum is a good low-temperature material, it is a good material for the manufacture of liquefied natural gas (LNG) vessel storage tanks and polar operation research vessels.
Three Applications of Aluminum on Ships
In general, the application of aluminum on ships is divided into three categories:
A type of structure
The so-called type of structure refers to the strength of the main structural components of the force, such as the hull, large ship deckhouses, ship bridges, missile launchers, electromagnetic gun orbit. The guns have been equipped with the "Ford", the world's larger aircraft carrier that was launched in the United States in October 2013. Its launch orbit is aluminum alloy and the test guns are made of aluminum alloy. Aluminum bombs are subjected to electromagnetic guns >
10,680KJ energy was used to fly out of the orbit at a speed of 7 Ma (Mach) and hit a goal of 360 km beyond land under the guidance of the global satellite positioning system.
Class II structure
This kind of structure refers to non-forced components or components with less stress, such as various habitats, fuel tanks, water tanks, storage cabinets, aluminum watertight doors, windows, and lids (marine rectangular windows, marine string windows, small Speedboat aluminum windows, aluminum skylights, aluminum shutters, various hatch covers, rectangular windows, mobile aluminum doors, weather-tight single-leaf aluminum doors for ships, cabin door, all types of ladders and springboards, passenger and driver seats and sofas Etc.), Sanitary facilities, pipes, ventilation, wind deflectors, brackets, streamlined casings, handles, etc. Most of them are made of alloy materials such as 6063, 6082, and 3003.
Three types of structure
This type of structure is mainly used functional materials for the production of interior parts of the warehouse and insulation, sound insulation materials. Aluminum and aluminum alloys have good anodizing coloring properties. After this treatment, they have a beautiful appearance and strong corrosion resistance. In addition to the use of various heat treatment can not be strengthened aluminum alloy materials, aluminum - plastic (aluminum - polyethylene, Al-PE) composite panels and foam aluminum also obtained more applications, foam aluminum board is a good sound insulation in the submarine engine room material. The core of the composite board is a plastic layer with thin 1100 or 3003 alloys on both sides or one side and aluminum alloys with a thickness of 0.1-0.3 mm. The surface of the aluminum plate can be subjected to anti-corrosion treatment, embossing, painting, printing and other deep processing. Its characteristics are light weight, appropriate rigidity, and better vibration insulation effect. The Japan Maritime Association and other countries' shipbuilding departments have been approved as internal decorative plates for ship ships, and can also be used as materials for doors and windows. The materials used in the past, such as FRP and wood, can be changed to such materials.
Aluminum alloy has been widely used on ships
Since the 1920s, aluminum alloys have become more widely used on ships. There are many examples of aluminum alloys used in the construction of aircraft carriers, cruisers, frigates, missile destroyers, submarines, speedboats, gunboats, and landing craft.
In 1926, the United States began to use aluminum alloys on warships in larger quantities because the Washington Navy regulations imposed strict restrictions on the displacement of ships. At that time, there were two patrol vessels that were to be converted into aircraft carriers. In order not to exceed the regulations, it was decided to use more aluminum to make non-structural parts to reduce the quality. For example, ventilation systems, bulkheads, flight deck fences, and aprons were all aluminum alloys.
Aircraft carrier aluminum alloy in application
The aircraft carrier is a huge object, huge in size, and well-built. It is a highly mobile combat platform and has an extremely urgent need to reduce the structural quality. Therefore, it is very important to control the quality of the aircraft carrier structure, which includes controlling aircraft carrier equipment, especially The quality of the superstructure is crucial to improve the tactical performance of the aircraft carrier.
For aluminum alloys with a displacement of more than 50 kt, the aluminum alloy material used is 500t~1000t. For example, the U.S. "Independence" (CVA62) aircraft carrier used 1019t aluminum, the "Enterprise" nuclear-powered aircraft carrier (CVA65) used 450t aluminum, and the French "Fochee" (R99) and "Kerimonte" (R98) The aircraft carrier used more than 1,000 tons of aluminum. The application of aluminum on aircraft carriers is of great significance for reducing its structural quality, improving stability, airworthiness, and other properties.
China's first carrier "Liaoning" was officially handed over to the Chinese People's Liberation Army Navy on September 25, 2012 for research, experimentation, and training.
There are more than 10 floors and more than 3,000 cabins below the flight deck of the “Liaoning Ship”, which enters the third floor. It feels like a maze. It is full of passages and cabins, and the total length of the ship’s channel is 10km. The "Liaoning" aircraft carrier is the ship of China's dream, carrying the dream of the nation to revitalize its dream and become a big ocean nation. There are 10 aircraft carriers in service in the United States, and China will have five or six vessels before 2025.
Water line length, m270
Side width, m75
Deep water, m10.5
Standard displacement, t55000
Full load displacement, t67500