Bimetall – compositional metal material

Bimetall – compositional metal material, which consists of two layers of various metals or alloys. Such can be combinations of steel and aluminum, titanium and molybdenum, titanium and aluminum, and many others. Thanks to such compositions, strength, corrosion stability, heat resistance of the material increases, its mass decreases, which, in addition to the structural advantage, also gives economic benefits.

Bimetalls are used in many industries, such as petrochemical, energy, nuclear, shipbuilding, instrument -building, etc. In most situations, the use of bimetalls is due to the fight against corroding factors. In this case, the main metal of the structure, such as steel, is covered on one or both sides by another metal, resistant to corrosion, such as copper, silver or brass.

The disadvantage of this method is that at the joints or cuts of metals, over time, corrosion processes that penetrate the material still begin. Bimetallic plates are widespread in the design of devices and devices, using the difference in thermal expansion coefficients of various metals. On this principle, many relay, thermometers, measuring devices are based on this principle. Babbitis is widely used to steel bearings to obtain an antifriction effect, that is, a reduction in friction.

The manufacture of bimetalls is carried out mainly by plating – hot rolling and pressing, as well as welding with an explosion. The plane is based on the diffusion of metals, with the deformation of sheets under the influence of heat treatment. As a result of rolling, it turns out a two -layer sheet with the necessary parameters. So, the main layer of bimetall gives it mechanical and strength characteristics, and the plate layer increases resistance to temperature, corrosion.

Despite the greater prevalence of the plate, the method of welding the explosion is technologically and economically more profitable. It implies the connection of metal plates during collision at high speed, due to the explosion. Thus, you can get two -layer sheets on an industrial scale at low costs. It can also be noted the method of gas -terminal spraying, which allows you to obtain almost any compounds of melting metals.

In addition, with the help of such spraying, you can create several layers that give various improvements in the properties of the metal. However, this method is so far too expensive to use it in large industries.

Share
Tweet
Pin it
Share
Share
You May Also Like
View Post

This object has such a fate that involuntarily allocates it among others in Kazakhstan. The bridge across the Ural River in the administrative center of the West Kazakhstan region began to be built in the “good old days”, that is, under the Soviet regime. Since the republic never had their own organizations specialized in this case, bridge builders from different Russian cities worked here here. Then there was a notorious “parade of sovereignty”, followed by an economic crisis. Although the construction of the bridge continued, however, the payment of the executed volumes was now constantly delayed, or even at all moved away for an indefinite period. For this reason, the bridge builders stopped working several times. However, the object in Uralsk is one of the most significant in Kazakhstan, and therefore did not forget about it: the press periodically woke up this topic. Increased attention is also explained by the fact that the bridge across the Urals does not just connect the two banks of the river, it makes up an important link on the shortest path from Central Asia to the European part of Russia. As a result, the story of the invitation of bridge builders from a neighboring state was repeated again and again, without a visible result. There is a rather funny moment in it. A couple of years ago, when the President of Kazakhstan Nursultan Nazarbayev arrived in Uralsk, the local authorities invited him to take part in the solemn open… bridge over the Urals. The head of state made sensory words and cut the red ribbon. But when the ceremony ended and the president left, the entrance to the bridge was closed. The fact is that every driver who would decide to update the shortest path from Central Asia to Russia could well have been on the other side, but at the bottom of the river. The object was not over. And the main difficulty was not so much in building a car transition through the Urals itself, but in the construction of multi -kilometer approaches to it through a constantly flooded floodplain. And work here still start and finish. And now in the republic they decided to return to the long -suffering object again. The Ministry of Transport and Communications of the Republic of Kazakhstan announced the competition for state procurement of works and services for the reconstruction of the bridge over the Ural River. The required delivery time within 2000. Potential suppliers who meet the qualification requirements stipulated in Article 10 of the Law of Kazakhstan “On public procurement” are allowed to the competition.