A huge part of the mined metals is used inindustry in the form of alloys. They learned to make even before our era. What are alloys? What is the name of the alloy, the basis of which is copper and zinc? Where is it applied? The answers to these questions are in the article.
What are alloys?
Alloys are materials from the mixtureseveral metals and other elements. They may contain random contaminants of natural components. One of the first known alloys was bronze. Products from it, people created in the IV millennium BC.
Alloys are made to improve the qualitymetals. For example, if gold ornaments last longer, they are stronger or have a certain shade, a small fraction of nickel, platinum, zinc or silver is added to them.
Mixing several components, you can changeproperties of the metal, increase the melting point and ductility, impart strength and hardness, increase wear resistance. The most common alloys are bronze, brass (copper-zinc alloy), cast iron, steel, babbit, win, duralumin.
They are used in engineering, construction,industry, aircraft building, etc. A mixture of nickel, magnesium and cobalt make magnets. Tin and lead were used to make cutlery, and cast iron was widely used for the manufacture of household items, such as pans or irons.
Alloy of copper with zinc
A mixture of copper and zinc is called brass. Like bronze, it appeared before our era. Since then, the technology of its manufacture has changed somewhat. Previously, to make brass, mixed copper with charcoal and zinc ore. In the 18th century, the Englishman James Emerson suggested mixing the metals themselves without the use of ore.
The basis of brass is copper. The content of zinc varies from 5 to 45 percent. Because of the yellowish color reminiscent of gold, in ancient Rome, brass was called orichalcum, which literally means "goldsmith".
Alloy copper with zinc is not always limitedonly these metals. It can contain a little bit of tin, lead, iron, manganese, nickel and other components. If tin is added more than zinc, you will get a completely different material - tin bronze.
Properties of brass
Depending on the amount of zinc, the color and qualitybrass vary. The smaller it is, the color of the material is more red and saturated. If the alloy of copper and zinc does not contain other elements, it is called simple brass, which is divided into two types: tombak (zinc to 20%) and yellow brass (zinc from 20%).
Material brass is very ductile and exhibits greater resistance to corrosion than copper. The melting point is from 880 aboutC to 950 aboutWith, with large proportions of zinc, it decreases. Metal can be perfectly welded, rolled and processed by pressure.
In the humid air yellow brass cracked. This can be corrected by annealing at a temperature of 250 aboutC. Multicomponent brass is better resistant to corrosion and is stronger. Addition of tin contributes to resistance to sea water.
The content of impurities in the alloy can be found inproduct marking. Capital letters indicate the name of the components. First comes the letter "L", then the remaining additional (alloying) elements. After them, according to the letter order, the percentage of substances is indicated, with the first two digits indicating the amount of copper in the alloy. So, marking ЛАЖ60-1-1 means that brass consists of 60% of copper, 1% of aluminum and 1% of iron, the rest is in zinc.
Where is brass used?
Brass has a good heat capacity. It is no accident that in ancient Russia samovars were made from it. In Rome, under Octavian Augustus, coins of sesteria and dupondia were minted from brass. In the Middle Ages it was used for making ornaments, framing compasses, decorating art objects.
And now the material is used everywhere. From brass make jewelry and small interior items. The special technique of artificial aging gives the products of brass a special charm. It is made of figurines, door handles, frames for mirrors.
High technological properties of brass allowUse material for the production of small building components, tubes, plates, tapes and wires. Alloy with lead is used for cars and watches, tombak is used for cladding steel and making radiator tubes. Of the composition with an aluminum content of 0.5%, they produce insignia, since it has a golden hue.</ p>