Aluminum alloys: properties and processing of metals

Aluminum is a very demanded metal both in construction and in other spheres of human life. However, in its pure form it is used very rarely. Most often used aluminum alloys.

All alloys can be divided into foundry and deformable. The first type is produced by the melting method, and for the production of second-class alloys, pressure is applied. Cast aluminum alloys are often represented by a combination of aluminum and silicon. Such metals are durable, have high resistance to corrosion, are well cut. As for the deformable alloys, among them, the duralumin is known, in which aluminum, magnesium, and copper are found. From this metal wire, profile, sheets, tape are made. Any alloy can be processed by any means.

The properties of aluminum alloys can be divided into physical, mechanical and chemical. As for physical properties, alloys have practically the same density as aluminum itself. They have high strength, which can compete with titanium and steel. But here it is necessary to take into account that the melting temperature of alloys is small (it is about 200 degrees). It is worth noting that aluminum alloys have good thermal conductivity, remarkably conduct electric current, are well welded and resistant to corrosion, although in pure aluminum these properties are much higher.

As for the mechanical properties, they become higher with an increase in the degree of doping. Presented aluminum alloys are used to construct structures of low and medium loading. It is worth noting that the properties of alloys vary greatly after heating to a certain temperature, which determines the use.

Since alloys must be processed before use, and to create certain structures, alloys have to be welded, attention should be paid to the fact that welding of aluminum alloys has certain characteristics. The process has some difficulties:

- Alloys are hard welded because of the oxide film that appears on the surface of the metal (it often pollutes the seam, which prevents normal fusion of the metal edges);

- the oxide film and the alloy itself have different melting points, the difference being significant;

- since the casting expansion of aluminum is quite high, after welding, the metal can seriously deform;

- alloys have high fluidity, therefore, when welding on metal, flows may appear.

For the welding of alloys, carbon or metal electrodes are mainly used. The process is carried out using a DC reverse polarity. Before starting work, the surface to be welded must be treated with acetone or gasoline and cleaned with a steel brush. To weld more qualitatively, the parts to be welded must be heated to a certain temperature (200 degrees). To get a good weld after welding, you should cool it slowly.