Transportation Industry
Transportation Industry
Shipbuilding
Due to their good resistance to seawater corrosion, many copper alloys, such as aluminum bronze, manganese bronze, aluminum brass, gunmetal (tin-zinc bronze), white steel, and nickel-copper alloy (monel alloy), have become standard materials for shipbuilding. Generally, copper and copper alloys account for 2-3% of the deadweight of warships and merchant ships.
The propellers of warships and most large merchant ships are made of aluminum bronze or brass. Each propeller of a large ship weighs 20-25 tons. The propellers of the Queen Elizabeth and Queen Mary aircraft carriers weigh 3-5 tons each. The heavy tail shafts of large ships are often made of "Admiral" gunmetal, and the conical bolts of the rudders and propellers are also made of the same material. Steel and copper alloys are also used in large quantities in engines and boiler rooms. The world's first nuclear-powered merchant ship used 30 tons of white copper condenser tubes. Aluminum brass tubes are used as large heating coils for oil tanks. There are 12 such oil storage tanks on a 100,000-ton ship, and the corresponding heating system is quite large. The electrical equipment on board is also very complex. The engines, motors, communication systems, etc. almost completely rely on copper and copper alloys to work. The cabins of large and small ships are often decorated with steel and copper alloys. Even for wooden boats, it is best to use steel alloy (usually silicon bronze) screws and nails to fix the wooden structure. Such screws can be mass-produced by rolling.
In order to prevent the hull from being contaminated by marine organisms and affecting navigation, copper coating is often used for protection; or copper-containing paint is used to solve the problem.
In World War II, in order to defend against German magnetic mines against ships, anti-magnetic mine devices were developed. A circle of copper belts was attached around the steel hull, and an electric current was passed to neutralize the ship's magnetic field, so that the mines would not be detonated. Since 1944, all Allied ships, a total of about 18,000 ships, have been equipped with this demagnetization device and protected. Some large battleships require a lot of copper for this purpose. For example, one of them has a 28-mile-long copper wire and weighs about 30 tons.
Automobiles
Each automobile uses 10 to 21 kilograms of copper, which varies with the type and size of the car. For a small car, it accounts for about 6 to 9% of its own weight. Copper and copper alloys are mainly used in radiators, brake system pipes, hydraulic devices, gears, bearings, brake friction pads, power distribution and power systems, washers, and various joints, accessories and accessories. Among them, the radiator uses a relatively large amount of steel. Modern tube-belt radiators use brass strips to weld radiator tubes and thin copper strips to bend into radiator fins.
In order to further improve the performance of copper radiators and enhance their competitiveness against aluminum radiators, many improvements have been made. In terms of materials, trace elements are added to copper to increase its strength and softening point without losing thermal conductivity, thereby reducing the thickness of the strip and saving steel; in terms of manufacturing technology, high-frequency or laser welding of copper tubes is used, and steel brazing is used instead of soft soldering that is easily contaminated by lead to assemble the radiator core. The results of these efforts are shown in Table 6.2. Compared with brazed aluminum radiators, under the same heat dissipation conditions, that is, under the same air and coolant pressure drop, the new copper radiator is lighter and significantly smaller in size; coupled with the good corrosion resistance and long service life of steel, the advantages of copper radiators are even more obvious. In addition, for environmental protection, the promotion and development of electric vehicles will increase the amount of steel used in each car by several times.
Railways
The electrification of railways requires a large amount of copper and copper alloys. More than 2 tons of special-shaped copper wires are required for each kilometer of overhead wires. In order to improve its strength, a small amount of copper (about 1%) or silver (about of%) is often added. In addition, the motors, rectifiers, and control, braking, electrical and signal systems on the train all rely on copper and copper alloys to work.
Aircrafts
Aircraft navigation is also inseparable from copper. For example: copper materials are required for wiring, hydraulic, cooling and pneumatic systems in aircraft, aluminum bronze pipes are used for bearing retainers and landing gear bearings, antimagnetic steel alloys are used for navigation instruments, and broken copper elastic elements are used in many instruments, etc.
