It is an alloy similar to gold, but much cheaper. Known as far back as Ancient Rome, but rediscovered in the 18th century. Combining the excellent properties of two chemical elements, brass has found a wide field of application for itself.
Structure
Despite the noble color and appearance, brass is an alloy of copper with zinc, gold or other precious metals are not there. In addition to these two components, other substances are also used to improve the physicochemical properties: manganese, tin, iron, silicon, nickel, lead, etc. As a rule, the proportion of these impurities is not more than 10%. Otherwise, the composition of brass is more or less constant, although the ratio of components may vary. Typically, the zinc content does not exceed 30-35%, however, in technical alloys, its share can reach up to 50%.
The properties
Since brass is an alloy of copper with zinc, its characteristics have something in common with their qualities. Depending on the ratio of the components, its color can vary from reddish to light yellow. Its density is 8500 kg / m 3 , and the melting temperature reaches 880-950 degrees Celsius. Brass is well processed by pressure in both hot and cold conditions, has good mechanical characteristics, resists the effects of the external environment, but blackens over time without coating. Brass and copper are not always easy to distinguish from each other to a non-specialist, nevertheless, the first one has hardness, wear resistance, it is less refractory, but more malleable and viscous, and therefore more convenient to process. Depending on the content of the base metal, the thermal and electrical conductivity of brass differ - the higher its proportion, the more pronounced these properties.
Meaning in history
Despite the fact that the most famous and most important alloy with copper is bronze, brass also played a role in history. Despite the fact that its second main component, zinc, was discovered only in the 16th century, it was known in ancient times. The Romans alloyed copper with galmei - ore, but this method has long been outdated. Secondly, brass was discovered in England in the 18th century and quickly gained popularity, because it very much resembled gold, for which it was often given out. In Russia, this alloy was often called "yellow copper." Even now, in some places you can find such a name.
After the “second birth”, crucibles were used to obtain brass, in which the temperature developed up to 1000 degrees Celsius. Zinc vapor saturated copper, and if there were no impurities in it, then the desired result was obtained at the output. Products from this alloy began to be used everywhere, since its low cost and properties allowed it. By the way, despite the fact that for a long time they wrote in history textbooks that the monument to Minin and Pozharsky in Moscow was cast in bronze, restorers said that in fact it was made of another alloy of copper - brass. Today, this substance still has a lot of fields of application, so, perhaps, a replacement worthy in terms of affordability and universality will be found soon.
Getting
As it has already become clear, brass is an alloy of copper with zinc and (if necessary) some other components, but there is one small problem. This difficulty is especially inconvenient in industrial production. The fact is that the melting points of zinc and copper separately differ too much, therefore, to facilitate the task of producing the alloy, a ligature is added - a small amount of the finished composition.
Further processing depends on the desired result. Other components are added to the alloy, alloyed, stamped, shaped, etc. Despite all the difficulties, the world production and consumption of this product remains at a high level.
Varieties and Standards
First of all, there are deformable and foundry brass. GOST provides for them separate numbers: respectively 15527-07 and 17711-93. In Russia, the alloy is marked as "L" with a number that indicates the proportion of copper. If there are a lot of components, then as a result the marking may look something like this: 66-6-3-3-2. This will mean that, in addition to 66% copper, this brand contains 6% aluminum, 3% iron and 2% manganese. The zinc fraction is calculated as the difference between 100% and the amount of other elements. In this case, it is 23%. By analogy, other brands of brass are also referred to. Such additives allow the alloy to acquire new properties and improve existing ones. Depending on the input into the composition of brass of certain substances, in everyday life it is called aluminum, siliceous, ferromanganese, etc.
In Europe and the USA, other brand names are accepted, such as CuZn37 or C27200. The ratio of impurities also varies slightly, but in general, the composition of brass in different manufacturers is quite homogeneous.
In addition, depending on the zinc content in the alloy, there are also different packagings (up to 10%) and semi-packs (from 10% to 20%). Still sometimes, certain brands acquire names in accordance with the scope of their main use. So distinguish between "marine", "sentry" and some other brass.
Application
The scope of use of this alloy can not be counted. The relative cheapness and ease of processing, as well as its properties allowed brass to become almost universal. It is drawn into wire and rods, stamped into sheets, even the finest foil is made of it.
Pipes, small and large parts, accessories, fittings - it is used in the automotive industry, instrumentation, chemistry, and it is also used in the manufacture of various decorative elements, insignia, etc. This is just a short list. It surrounds us everywhere, but brass is an alloy of copper and zinc - quite common elements. So, perhaps, its versatility and accessibility is only at hand for everyone.
In jewelry
It is generally believed that jewelry should be made of precious metals: gold, silver, platinum. But fashion has its own rules, and for some time in the daytime, many women prefer discreet jewelry. Brass, the color of which is close to gold, is irreplaceable in this case. In addition, it is perfectly polishable, so that with the proper composition and talent of the jeweler, jewelry made of alloy can look very beautiful and expensive. So that non-specialists will not even suspect that this is not gold, but brass. A photo usually just does not convey the beauty of artfully executed products, so it is better to choose such jewelry in person.
It happens that fashionistas suffer from allergies and irritation. At first glance, it may seem that brass is the one to blame. But, as a rule, this is not so. In most cases, nickel causes a pathological reaction, which makes the color and overall appearance of the alloy much more beautiful. If there is a tendency to an allergy to metals, it is better to choose jewelry that does not contain this component. Usually manufacturers indicate this separately.
Analogs
Since brass is an alloy of copper with zinc, and the first there is more, it may seem that pure metals (each separately) have better properties, and such difficulties are used to reduce the cost of the material. In fact, this is not so. Pure copper in its pure form has such disadvantages as corrosion resistance, less ductility compared to alloys, and zinc is extremely fragile. Brass, on the other hand, organically combines the best properties, compensating for the shortcomings of both components.
Other copper alloys - bronze, cupronickel, etc. - also can not be fully called analogues. The first is less ductile and coarser, while the second is quite refractory and can cause skin irritation due to nickel content. In addition, external characteristics also put brass first. The color, similar to gold, compares favorably with not too attractive brown bronze and silver cupronickel.
World market
Industrial production of brass began almost immediately after its reopening. Assessing its unique properties, metallurgists began to develop a new direction in the industry. Today, the production and consumption of brass mainly depends on the state of the global copper market. Its stable growth gives reason to believe that demand for alloys has not yet fallen. Moreover, forecasts regarding the future of these industries are more than favorable, despite problems such as a decrease in ore quality, insufficient infrastructure, social and political tensions in the largest copper suppliers - Chile and some African countries.
The main consumers of copper, and therefore brass, are the economically developed countries of Europe, as well as the USA, China, Japan and some others. In recent years, the demand for these substances is only growing, primarily due to Asians. Having made a giant leap in the mid-2000s, Cu prices remain at a record high. However, in 2016, a peak in supply is expected, which is likely to provoke a decline in quotations.