Brass is an alloy of copper with ... Composition of brass

It's an alloy that looks like gold, but it's much cheaper. Known in ancient Rome, but re-discovered in the XVIII century. Combining the excellent properties of two chemical elements, brass has found a wide field of application for itself.

Composition

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 used to improve the physico-chemical properties: manganese, tin, iron, silicon, nickel, lead, etc. As a rule, the proportion of these impurities is no more than 10%. In other respects, the composition of brass is more or less constant, although the ratio of components can vary. Usually the zinc content does not exceed 30-35%, however in technical alloys its share can reach up to 50%.

Properties

Since brass is an alloy of copper with zinc, its characteristics resonate with their qualities. Depending on the ratio of components, its color can vary from reddish to light yellow. Its density is 8500 kg / m ³ , and the melting point reaches 880-950 degrees Celsius. Brass is well processed by pressure in both hot and cold state, has good mechanical characteristics, resists the environment, but without coating it blackens over time. Brass and copper can not always be easily distinguished from one another by a layman; nevertheless, the former has hardness, durability, it is less refractory, but more malleable and viscous, and therefore more convenient to process. Depending on the content of the base metal, the heat and electrical conductivity of brass differ - than its share is higher, the more pronounced these properties are.

Importance 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 XVI century, it was known in ancient times. The Romans fused copper with galley-ore, but this method has long been obsolete. Secondarily, brass was discovered in England in the XVIII century and very quickly gained popularity, because it was very reminiscent of gold, for which it was often issued. In Russia this alloy was often called "yellow copper". Even now here and there you can find such a name.

After the "second birth" for the production of brass, crucibles were used, in which the temperature was raised to 1000 degrees Celsius. Zinc vapor was saturated with copper, and if there were no impurities in it, then the desired result was obtained. Products from this alloy began to be used everywhere, because its cheapness and properties allowed it. By the way, despite the fact that history books have written for a long time that the monument to Minin and Pozharsky in Moscow is cast from bronze, restorers said that in fact it is made of another copper-brass alloy. Today, this substance still has a lot of applications, so there is probably no replacement for a worthy and affordable replacement.

Receiving

As it became clear, brass is an alloy of copper with zinc and (if necessary) some other components, but there is one small problem. Especially this difficulty causes inconvenience in industrial production. The fact is that the melting points of zinc and copper separately differ too much, so to simplify the task of obtaining an 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, distinguish between deformable and foundry brass. GOST provides for them a separate number: respectively 15527-07 and 17711-93. In Russia, the alloy is labeled as "L" with a figure that indicates the proportion of copper. If there are a lot of components, then the marking may look something like this: LAZhmts66-6-3-2. This will mean that, in addition to 66% of copper, this grade contains 6% of aluminum, 3% of iron and 2% of manganese. The proportion of zinc is calculated as the difference between 100% and the number of other elements. In this case it is 23%. By analogy, other brands of brass are also called. Such additives allow the alloy to acquire new properties and improve existing ones. Depending on the introduction into the composition of brass of certain substances, in everyday life it is called aluminum, siliceous, ferromanganese, etc.

In Europe and the United States, other designations of brands, such as CuZn37 or C27200, have been adopted. Also, the ratio of impurities differs slightly, but in general, the composition of brass from different manufacturers is fairly homogeneous.

In addition, depending on the content of zinc in the alloy, they also distinguish tombstones (up to 10%) and semi-packages (from 10% to 20%). Still sometimes some brands acquire names in accordance with the sphere of basic use. So distinguish "sea", "sentry" and some other brass.

Application

The sphere of use of this alloy can not be considered. Relative cheapness and ease of processing, as well as its properties allowed the brass to become almost universal. It is pulled into wire and rods, stamped into sheets, even the finest foil is made of it.

Pipes, small and large parts, fittings, fittings - it is used in the automotive industry, instrument making, chemistry, and it is used in the manufacture of various decorative elements, insignia, etc. This is only a short list. It surrounds us everywhere, and in fact brass is an alloy of copper with zinc - fairly common elements. So, perhaps, its universality and accessibility is only at hand.

In the jewelry business

It is usually believed that jewelry should be made of precious metals: gold, silver, platinum. But the fashion has its own rules, and for some time now in the daytime many women prefer low-key costume jewelry. Brass, whose color is close to gold, in this case is indispensable. In addition, it is perfectly polished, so that with the proper composition and talent of the jeweler, the jewelry made of an alloy can look very beautiful and expensive. So that non-experts do not even suspect that it's not gold, but brass. The photo usually just does not convey the beauty of artfully executed products, so it's better to choose such decorations personally.

It happens that women of fashion suffer from allergies and irritation. At first glance, it may seem that in all it is brass. But, as a rule, this is not so. In most cases, the pathological reaction is caused by nickel, which makes the color and overall appearance of the alloy much more beautiful. If there is a tendency to allergy to metals, it is better to choose jewelry that does not contain this component. Usually manufacturers specify it separately.

Analogues

Since brass is an alloy of copper with zinc, the first of which is larger, it may seem that pure metals (each separately) have better properties, and such complexities are used to reduce the cost of material. In fact, everything is not so. Copper in its pure form has such disadvantages as instability to corrosion, less plasticity in comparison with alloys, and zinc is extremely fragile. Brass also organically combines the best properties, depending on the disadvantages of both components.

Other copper alloys - bronze, cupronickel, etc. - also can not be fully described as analogs. The former is less plastic and more coarse, while the second substance is fairly refractory and because of the nickel content it can cause skin irritation. In addition, external characteristics also put brass in the first place. The color, similar to gold, favorably differs from not too attractive brown bronze and silvery silver.

World market

The industrial production of brass began almost immediately after its reopening. Having evaluated 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 world copper market. Its stable growth gives grounds to believe that demand for alloys is not falling yet. Moreover, forecasts about the future of these industries are more than favorable, despite such problems as the reduction of ore quality, insufficient infrastructure development, 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 United States, China, Japan and some others. In recent years, the demand for these substances has only increased, primarily due to Asians. Having made a giant leap in the middle of the 2000s, Cu prices remain at the same record high level. However, in 2016, the peak of supply is expected, which is likely to trigger a decline in quotations.