Aluminio

Aluminium in aircraft construction
The history of world aviation is closely related to aluminium and the history of creating aluminium alloys, and the more durable and reliable aluminium became, the higher, farther and safer airplanes flew. But, before it became the essential and most important material for aircraft manufacturers, aluminium navigated a long route from pure metal tohigh-strength alloys.
The first person who managed to understand the potential of aluminium in the aerospace industry was the writer Jules Verne, who provided a detailed description of an aluminium rocket in his fantastic novel ‘Journey to the Moon’ in 1865. In 1903, the Wright brothers got the first airplane off the ground, in which parts of the engine were made of aluminium.
‘Aircraft’ aluminium appearedfor the first time in Germany in the early 20th century. At that time, it was just starting to ‘come into vogue’. The technology of its industrial production had already been perfected, but the amounts of smelt metal were still small. Many scientists then set themselves the goal to solve the task of aluminium reinforcement. Among them was Alfred Wilm, a German physicist. During his experiments onselecting components for aluminium reinforcement, unexpectedly for himself and the entire scientific community, he discovered the ‘aging effect’ of the aluminium alloy, which consists in the considerable improvement of metal strength after its quenching for a long period. Alfred Wilm’s discovery was patented and implemented in production at Duerener Metallwerke AG plant. In 1909, the plantofficially presented its products: the ultra-strong alloy, duralumin (aluminium, copper (1.3%), magnesium (2.8%) and manganese (1%)). In fact, this metal became the base for development of aircraft alloys.
The advantages of Duerener ‘aluminium’ were appreciated by Professor of Thermal Dynamics, and Aircraft Manufacturer of Aachen University, Hugo Junkers. More than once he attempted to assemble anall-metal airplane: On December 15th, 1915 testing of the J1 glider made of sheet iron was held at the military airfield of Deberitsa. But the representatives of the military administration ‘rejected’ the airplane, calling it ‘a tin donkey’: J1 – too heavy, with a low climbing capacity and manoeuvrability, and did not comply with the requirements of military aviation. Junkers understood that the major‘culprit’ of the failure was metal. He needed an alternative to thick (up to 1 mm) iron sheets. And this alternative was found!
Duralumin met all the requirements of Hugo Junkers: high strength, forgeability, and the incredible lightness for a metal were very much to the point. As soon as in 1917, the J.7 fighter entirely built of the ‘light’ metal took off from Adlershof airfield.
In the sameyear, production of Junk J.1 military airplanes was started; they were ordered by the German Ministry of Defence for participation in the First World War campaigns. During the military campaign, duralumin completely proved Junkers’ calculations: The metal reliably protected the pilot from bullets and shells. Junk J.1 airplanes were named ‘flying tanks’. There is a recorded case when duraluminsustained 480 bullet shots on the wings and fuselage, and the airplane not only completed the combat mission, but also successfully landed at base.

The success of the first J.7 and Junk J.1 airplanes predetermined the breakthrough in the development of German military aviation. Duralumin became the favourite of Junkers’ design department. Germany won the battle for the sky, however its rivals werenot going to surrender, and developments of ultra-strong aluminium alloys were in full swing in the USSR and USA.
In 1918, on the insistence of the manufacturer A.N. Tupolev and Professor of Moscow State University N.E. Zhoukovsky, the Central Aerohydrodynamics Institute (CAHI) was established, where development of new models of airplanes and metal alloy studies were started. CAHI worked in...