Aerospace and aviation
Modern seagoing vessels are increasingly being built with so-called marine aluminium, a generic term for the aluminium-magnesium alloy widely used in mechanical engineering ( Magnesium content is between 3% and 6%). These alloys have excellent corrosion resistance in both fresh and salt water. Important properties of aluminium for marine applications include strength and weldability. Aluminium sheets and plates for marine use are produced by cold or hot rolling, while profiles, bars and tubes are produced by rolling, drawing or pressing.
In 1891, the first partially aluminum submarine "LeMigron" was built in Switzerland.A few years later, a 58-metre torpedo boat was built in Scotland out of aluminium.It was very sturdy and had a speed of 32 knots, which was unheard of at the time.The ship, known as the Eagle, was built for the Russian navy.
Duralumin or aluminium-magnesium alloys are also used in the construction of high-speed hydrofoil passenger vessels with speeds in excess of 80 kilometres per hour. In order to ensure high speed and manoeuvrability, these boats need to be very light, so aluminium comes in handy again.
Marine aluminium has a corrosion rate 100 times lower than steel. In the first year of operation, steel corrodes at a rate of 120 millimetres per year, while aluminium corrodes at a rate of only 1 millimetre per year. In addition, the strength of marine aluminium is outstanding. It is flexible and even a powerful blow cannot punch a hole in the hull of a welded aluminium boat. Aluminum boat frames improve seaworthiness, provide better safety, and reduce maintenance costs.
It is for this reason that aluminum is used in yachts, motorboats, cutters, and underwater craft. Generally, sport boats are made from aluminum from the keel to the mast, which gives them an advantage in speed, while high-capacity boats are made from steel manufactured, while the superstructure and other auxiliary equipment are made of aluminum to reduce weight and increase cargo carrying capacity.