A huge part of the mined metals is used in industry in the form of alloys. They learned how to make them before our era. What are alloys? What is the name of the alloy, the basis of which is copper and zinc? Where is it used? The answers to these questions are in the article.
What are alloys?
Alloys are materials from a mixture of several metals and other elements. They may contain random impurities of natural components. One of the first known alloys was bronze. Man made products from it back in the 4th millennium BC.
Alloys are made to improve the quality of metals. For example, to make gold jewelry last longer, be stronger or have a certain shade, they add a small fraction of nickel, platinum, zinc or silver.
By mixing several components, you can change the properties of the metal, increase the melting point and ductility, give strength and hardness, increase wear resistance. The most common alloys are bronze, brass (an alloy of copper with zinc), cast iron, steel, babbit, win, duralumin.
They are used in mechanical engineering, construction, industry, aircraft manufacturing, etc. Magnets are made from a mixture of nickel, magnesium and cobalt. Tin and lead were previously used for the manufacture of cutlery, and cast iron was widely used for the manufacture of household items, for example, pans or irons.
Copper alloy with zinc
A mixture of copper and zinc is called brass. Like bronze, it appeared before our era. Since then, its manufacturing technology has changed somewhat. Previously, to make brass, copper was mixed with charcoal and zinc ore. In the 18th century, Englishman James Emerson proposed mixing the metals themselves without using ore.
The basis of brass is copper. Zinc content varies from 5 to 45 percent. Because of the yellowish color, reminiscent of gold, in ancient Rome, brass was called heirloom, which literally means "golden-copper".
The alloy of copper with zinc is not always limited only to these metals. It may contain some tin, lead, iron, manganese, nickel and other components. If tin is added more than zinc, then a completely different material will be obtained - tin bronze.
Brass properties
Depending on the amount of zinc, the color and quality of the brass varies. The smaller it is, the color of the material is more red and saturated. If the alloy of copper with zinc does not contain other elements, it is called simple brass, which is divided into two types: tompak (zinc up to 20%) and yellow brass (zinc from 20%).
Brass is very ductile and exhibits greater corrosion resistance than copper. The melting point is from 880 ° C to 950 ° C, with large proportions of zinc it decreases. Metal perfectly lends itself to welding, rolling and pressure treatment.
In humid air, yellow brass cracks. This can be corrected by annealing at a temperature of 250 ° C. Multicomponent brass better resists corrosion and is stronger. The addition of tin promotes resistance to sea water.
The content of impurities in the alloy can be found on the product labeling. Capital letters indicate the name of the components. First comes the letters "L", then the remaining additional (alloying) elements. After them, in accordance with the alphabetical order, the percentage of substances is indicated, and the first two digits indicate the amount of copper in the alloy. So, the marking LAZH 60-1-1 means that brass consists of 60% copper, 1% aluminum and 1% iron, the rest is zinc.
Where is brass used?
Brass has a good heat capacity. It is no coincidence that in ancient Russia samovars were made from it. In Rome, under Octavian Augustus, sestercia and dupondia coins were minted from brass. In the Middle Ages, it was used for making jewelry, framing compasses, and decorating art objects.
And now the material is used everywhere. They make jewelry and small interior items from brass. Special artificial aging technique gives brass products a special charm. Figurines, door handles, mirror frames are cast from it.
The high technological properties of brass make it possible to use the material for the production of small building parts, tubes, plates, tapes and wires. Lead alloy is used for automobiles and watches, tompak is used for cladding steel and manufacturing radiator pipes. Insignia are made from a composition with an aluminum content of 0.5%, since it has a golden hue.