Brass is an alloy based on zinc and copper. The percentage of zinc in the alloy can be 5 - 45%. Zinc, unlike copper, is cheaper, which is why its introduction into the composition not only increases the technological, anti-friction and mechanical properties of the alloy, but also reduces its cost.

brass properties

Brass alloys excellent pressure handling. The mechanical performance is quite high, but the corrosion resistance is satisfactory. If we compare distinctive features brass with bronze, then its anti-friction properties, corrosion resistance and strength are lower. Alloys are not very stable in salt water, air, solutions of most organic acids and carbon dioxide solutions.

Brass, unlike copper, has better corrosion resistance. But as the temperature rises, the rate of corrosion also increases. Moreover, such a process is noticeable in products with thin walls. Corrosion can be caused by: high humidity, traces of sulfur dioxide and ammonia in the air. To prevent this phenomenon, products from this composition are subjected to low-temperature firing after processing.

Almost all alloys when the temperature drops do not become brittle and remain elastic, which allows them to be used as an excellent structural material. Thanks to more high rate recrystallization temperature, in contrast to copper, at elevated temperatures, the creep of brass is lower. At a temperature of 300-600 C, the property of brittleness appears due to the fact that additions insoluble at low temperatures (for example: bismuth, lead) create fragile layers between the crystals. As the temperature increases, the impact strength decreases. Unlike copper, the thermal and electrical conductivity properties of brass are worse.

The composition of brass as a percentage

The main components - zinc and copper - are used in ratios of 30% and 70%, respectively.

More than 50% of the zinc used in the manufacture of brass comes from recycled waste. Technical brass alloys made of 47–50% zinc. According to the composition, alpha and beta brass are distinguished:

• Two-phase formulations are 48-50% zinc and contain less than 5% lead.
• Single-phase alpha compounds have about 30% zinc.

Chemical composition

Brass is made from copper and zinc. Often her compared to bronze, since the alloy of brass and bronze combines the same component - copper. Brass, which differs in composition from bronze, has as its second component not tin, but zinc.

Zinc is a chemical constituent element of a minor subgroup of the second group of the fourth period of the periodic system of Mendeleev. At normal conditions rather fragile bright blue transition material (covered with a small layer of zinc oxide in the open air and darkens). In nature, as a separate metal, zinc does not exist.

Copper is a chemical constituent element of the eleventh group of the fourth period of the periodic system of Mendeleev. This plastic transition material bright golden color (when an oxide layer appears, copper becomes red-yellow).

Due to zinc and copper (except for the main α-solution), a whole list of electronic stages of type β, γ, ε. As a rule, the composition of brass has α- or α+β' phases:

• α-phase– a stable copper and zinc material with a face-centered crystalline copper cubic lattice.
• β'-phase– a structural material based on the chemical combination of CuZn with a ratio of 3/2 and an elementary and simplest cell.

Dependence on heat treatment:

• If high temperature, then the β-phase has a chaotic arrangement of atoms and an increased volume of a homogeneous composition. In this state, the phase becomes quite plastic, if the temperature is less than 453-469 C, then the atomic structure of copper and zinc acquires order and is indicated as β'.
• β' is more brittle and rigid, the γ-phase contains the Cu5Zn8 electronic combination.

Compositions with a single phase are characterized by increased plasticity; β'-phase is less plastic and more durable.

Separation based on the content of zinc alloy:

Brass production

Brass lends itself well to forging, malleably deforms, quite viscous, accepts different forms under the impact of a hammer, stamped into various parts or stretched into a wire. The alloy is relatively ductile cast and melts at a temperature lower than that of copper.

Manufacturing process performed:

• In crucibles made of refractory clay. Crucibles are heated in flame or shaft furnaces.
• in reverberatory ovens.

During the mixing of zinc and copper, the composition is cast into pre-prepared sand molds. Some part of the zinc evaporates that must be remembered during the formation of the metal alloy.

Derivatives of brass

– type of wrought alloy. It contains zinc and copper by 2% -13% and 87-98%, respectively.

Tompac is different:

• reduced friction force;
• rust resistance;
• high elasticity.

Compositions of copper, consisting of 11-22% of zinc, are called semi-tompaks.

Tompac excellent weldable with stainless steel and other precious metals. Tompac is used for the manufacture of a combined composition of brass and steel. Thanks to its golden color, accessories, various medals and art products. Tompak lends itself well to enameling, gilding and pressure treatment at low and high temperatures.

- used for the manufacture of shaped products and semi-finished products using casting. Has 51-80% copper. In the role of additional elements used: aluminum, silicon, manganese, iron, lead and tin. Main differences:

• has resistance to friction with other elements;
• reduced tendency to decay of elements;
• does not rust;
• easy to handle due to the liquid consistency;
• excellent mechanical performance.

Often foundry brass used for mass production:

Automatic brass It is a lead type of alloy. It has the following composition:

• 24.3-42.8% - zinc;
• 56-76% - copper;
• 0.4-0.9% - lead.

The addition of lead during machining contributes to the appearance of loose and short chips, which reduces the wear of the separating mechanism and makes it possible to use high-speed machining of parts.

Mechanical characteristics automatic brass directly depend on its state of aggregation and components:

• cold-worked;
• soft.

This type of alloy is made in the form of:

• stripes;
• tapes;
• sheets;
• bars.

At the same time, sheets are made:

• watch parts;
• bolts;
• nuts and other mass-produced items.

How can you tell brass alloy from bronze

It is possible to distinguish brass from bronze and, in addition, to find out the exact composition only in chemical laboratory(for example, using spectroscopic analysis). Alas, at home (especially if you can’t scratch or otherwise deform the product), the range of possibilities is rather limited. However, there is an algorithm that shows, albeit not very accurate, but still results.

You will need:

• calculator;
• accurate scales;
• transparent container with water;
• samples of brass and bronze with chips;
• microscope or strong loupe.

Start with visual analysis. It is necessary to thoroughly clean the product and place it under sunlight. Usually bronze is darker than brass, and if we consider the color, then bronze turns into a “red” spectrum (from red to brown), and brass into “yellow”, sometimes even up to white. But this method is not very inaccurate, so go to the second step.

Do a composition analysis on density. You will need a transparent container with water and an accurate scale. Having lowered the product into water, we find out the volume, then we determine the mass. Density is the ratio of the mass of an object to its volume, translated into kg / cu. m. Most often, bronze is denser than brass, while the dividing line is at 8700 kg / cu. m. So, 8400-8700 kg / cubic meter - most likely brass. 8750-8900 - most likely bronze.

And in the end, composition structure. I must say that samples are needed here - objects where both brass and bronze can be accurately determined in the composition, and the samples must have chips.

A strong magnifying glass or microscope will be needed for analysis. The analysis is carried out by placing in the field of view both the sample and the subject of analysis. What do you need to pay attention to? On the structure of the composition - namely, its grain. Usually bronze has a coarser and coarser grain than brass.

From an alloy of copper and zinc, an alloy is produced, which is called brass. At the same time, many things change from the percentage of these pure metals, for example, the density of brass, its ductility, electrical conductivity, and others. In addition to the base metals, the composition of the alloy includes other elements that affect obtaining the special properties of brass required for a particular application.

Historical reference

According to historical information, the first metals used by man were copper and gold. Both metals are very soft in their pure state, so their use in human life is quite limited. In particular, copper has been used by ancient people since the beginning of their use of fire, and since the time of the Roman Empire, this metal has been used more intensively in the manufacture of pipes, military weapons, decorations for statues and for other purposes.

To improve the characteristics of pure metals, for example, greater hardness and strength, over time, a person came up with the idea of ​​mixing them. So, around 3500 BC, bronze was obtained in Mesopotamia - an alloy of copper and tin, which had a high resistance to corrosion and was more durable than each pure metal separately. Due to these properties, bronze began to be used for the production of weapons and tools.

Around 1400 BC, brass was discovered - an alloy of zinc and copper, which showed excellent resistance to deformation, had high ductility at low and high temperatures, and had high resistance to corrosion and mechanical wear. However, its use became widespread only in 250 BC with the start of coin production in the Roman Empire.

Since that time, the use of brass has been carried out in various areas of human activity, from weapons to jewelry. In the 15th century, it began to be used for the production of astronomical instruments, and with the advent of printing, the alloy began to be actively used in printing houses. From the middle of the 16th century in Europe, bolts and nuts were made mainly from brass, copper and bronze. This alloy was used to make watch gears, and in the 17th century in Holland, brass was used to make an optical telescope.

The composition and properties of the alloy

The proportions of metals in an alloy can vary widely, which affects the creation of a material with the desired properties. In industrial alloys, the percentage of zinc is always below 50%. The composition determines the following properties of the material:

• fusibility;
• forming ability;
• ductility;
• stamping ability;
• mechanical processing ability.

At low temperatures, brass can be made into sheets of various thicknesses or drawn into wire. The density of brass and also depend on the composition. In general specific gravity brass varies from 8.4 g/cm3 to 8.7 g/cm3, and the melting point is between 900 °C and 940 °C.

Pure copper has a density of 8.96 g/cm3 and a melting point of 1084 °C, while pure zinc has a density of 7.14 g/cm3 and a melting point of 420 °C, that is, these two are close to the properties of copper, due to its greater relative amount in alloy compared to zinc.

Brass is mainly used as decorative jewelry due to its appearance and luster, similar to gold. This alloy is also used in devices that require little friction between working parts, for example, in locks and various valves. Finds an alloy and its application in electrical appliances, and also due to its acoustic properties, it is used in the manufacture of some musical instruments such as trumpets and bells.

Mankind has been familiar with brass since prehistoric times, even before the discovery of zinc itself. This alloy was originally made by mixing copper and the mineral hemimorphite, which is a natural source of zinc. A mine for the extraction of hemimorphite was opened in one of the villages of modern Germany. This mine functioned during the Roman Empire. In the process of mixing copper and hemimorphite at high temperature, zinc is released from this mineral and alloyed with copper.

The physical properties of brass include the following characteristics:

Types of brass

Types of brass differ from each other in different zinc content in the composition. Depending on the percentage of zinc in the alloy, there are three main groups:

• The first group with a percentage of zinc less than 34%.
• The second group with a percentage of zinc from 33 to 44%.
• Alloys of the third group contain more than 42% zinc and are of limited use.

Alloy classification

According to this division into groups, depending on the zinc content, the following classification of ordinary brass is introduced:

• Red alloys. They are mainly used in the jewelry industry due to their appearance (brass can look like gold). Material with 10% zinc is similar to bronze, therefore it is used as its imitation; 15% zinc gives the material a reddish color, this alloy is used in car radiators; an alloy with 20% zinc has a good drawing, so it is used for the manufacture of pipes.
• yellow materials. Zinc in them contains from 25% to 35%. They are mainly used for sleeves and springs.
• Alpha-beta brass with a zinc ratio of 36 to 42%. They are less malleable than red and yellow brasses, so they are not used for making plates at low temperatures. Alpha-beta alloys are machined at high temperatures, so in the XIX they were used for some ship structures.

Some alloys have been called special alloys, such as similor alloy. Similor is 80% copper and 20% zinc. Other special materials are "Prince Albert metal" (copper 86%, zinc 14%), "crisocol" (82% copper, 6% zinc, 6% tin).

In addition to the main elements, brasses contain other elements in minimal quantities, so these alloys are malleable and ductile at low temperatures, and some materials are not ductile at any temperature. All types of this material become brittle near the melting point.

Due to the zinc content, brass is harder than pure copper. At the same time, the alloy is easier to process on various mechanical machines, it is easier to mint and melt products. Also, the alloy is resistant to the oxidation process in a salt environment, and its ductility makes it possible to produce thin metal sheets. Plasticity depends on three factors: temperature, structure and composition, and even minimal amounts of other elements can significantly change this physical property of the alloy.

The machinability of brass is greatly enhanced by the addition of a small amount of lead. This element practically does not dissolve in it and forms globular particles, which greatly facilitate the machining process. In addition, lead is a good lubricant due to its low melting point, this fact significantly reduces the wear of the cutting tool during material processing. Brass is practically unaffected heat treatment, only the processes of recrystallization and homogenization annealing are used for it.

Special materials

Special brasses are materials in which, in addition to copper and zinc, other elements are added to in large numbers in order to give them the appropriate properties. The most common special brasses are as follows:

• with the addition of aluminum;
• the addition of iron increases the hardness and rigidity of the alloy compared to standard brass;
• the addition of lead gives the material mechanical resistance and increases the ability to process;
• the addition of manganese increases the strength of the material and reduces its malleability and ductility;
• the addition of tin gives strength to the material during drawing, while at the same time increasing its corrosion resistance. In this case, there are two well-known alloys: “metal admiral”, which has a high resistance to corrosion, therefore it is used as condenser tubes; "marine brass" - contains 40% zinc in its composition and is widely used in sweet and salty water;
• silicon additive (so-called bronsil) increases corrosion resistance and is used in the manufacture of valves, pumps and gears;
• complex brass with the addition of various elements, which makes it highly resistant to oxidation and cavitation, which is why it is included in the propellers of ships.

Areas of use

The use of brass covers a wide variety of areas of human activity. Thus, the golden color of the alloy led to its use in jewelry and various decorative elements. It is also used in the boiler business, in the production of military equipment and ammunition, in the manufacture of wires and pipes for capacitors, electrical terminals and cash coins.

Due to its resistance to destruction in salt water, the metal is used in the manufacture of equipment for various marine vessels, and its acoustic properties make it possible to make wind instruments: pipes and accordions. Due to its bactericidal properties, the alloy is used to make door handles in hospitals and hospitals.

If we talk about the use as a decor, then we should highlight the production of lamps, lamps, cornices and some jewelry. Such things are produced mainly in the countries of Eastern Europe, on the territory of the CIS countries, as well as in many Arab and some Asian states.

One of the interesting properties of brass, which is unusual for metals, is the absence of sparks during mechanical action on the product. This unique characteristic makes it possible to use the material as vessels for storing and transporting flammable liquids.

Due to the ease of machining, high wear resistance and low price, the material is used for the manufacture of a variety of valves. Due to its high resistance to corrosion and cavitation, brass is used to make ship propellers. The material is also used in the production of some parts of modern computers.

Brass is an alloy of zinc and copper, the existence of which people have known since antiquity. It began to be produced by the ancient Romans. And although at that distant period they did not yet know about the existence of zinc, they learned how to use zinc-containing raw materials in the metallurgical sphere very successfully.

Currently, various brass alloys are used in a variety of economic areas. Therefore, it will be useful to know about the characteristics, properties and features of the application of this unique material.

This is a type of material, the main elements of which are copper and zinc. In addition, brass may contain additional components such as silicon, tin and lead.

Alloy characteristic

Brass is macroscopic material with a homogeneous structure. It usually contains metal components. It differs from the substance itself in its properties, which are provided by the phase structure (microstructure or crystalline structure). So, thermal and electrical conductivity, which is characteristic of metals, in any case is also a property metal alloy. However, along with this, the physical parameters can change if a certain phase becomes dominant.

For example, if we consider brass, then an increase in the zinc content has a non-linear effect on the properties of this material and its grade. In copper, zinc can dissolve up to 39 percent. If this value is reached, then the composition acquires a special structure and plasticity, but its strength is markedly reduced. If the proportion of zinc is increased, then a different crystalline phase appears, characterized by an increase in strength characteristics and a decrease in ductility.

Any metal alloy has this feature. In general, all copper-based alloys are divided into bronzes, brasses and solders. Bronzes are compositions of tin and copper, aluminum and beryllium. Solders can have very complex compositions. However, if the material in question can be easily distinguished from solder, then with bronze everything is somewhat more complicated.

They have very similar appearance, but completely different properties:

The material is mainly used in jewelry. For the production of large decorative details - interior items, decorations for stairs (forged) - it is recommended to use bronze.

Advantages and disadvantages

Every metal has special properties that can be attributed to both advantages and disadvantages. It all depends on the situation. In construction, brass is used extremely rarely, which is more evidence of the relevance of other materials, and not at all about the disadvantages of the alloy.

The main advantage of brass- a small mass, which determines the popularity of the material in rocket and aircraft construction. IN living conditions this is only necessary in situations where, for example, a light water supply system is needed.

Also, the alloy has excellent decorative properties. It has a very varied and attractive color palette. Accessories and fittings, household items and decor, made using brass, will always be beautiful, emphasizing the luxury and elegance of the interior. At the same time, the color of brass is preserved for a very long time.

The material also has low thermal conductivity., which is often used for the manufacture of systems and objects for which the preservation of heat is very important. We are talking about the production of bathtubs or furniture.

Brass is a diamagnetic metal, meaning it is pushed out of any magnetic field. This alloy has long been used to make compass frames. Now this quality is actively used in instrument making.

The corrosion resistance of the material is even greater than that of ordinary copper, but it decreases greatly as the temperature increases. Therefore, it is very beneficial to use brass pipes for water supply. For the heating system, it is still better to take a pipeline made of copper.

Composition and structure

There are two types of brass alloys:

• Multicomponent.
• Two-component.

Brass of the multi-component type, in addition to zinc and copper, may include other non-metals and metals. They have a significant impact on the final properties of the alloy. Thus, the introduction of tin into the composition increases the resistance of the material to the effects of sea ​​water. And the addition of, for example, nickel, increases the strength of the brass product.

Two-component alloys typically include zinc and copper in varying proportions.

Another classification method refers to processing methods:

• Deformable brass can be bent, rolled, and given a different shape even at home. These alloys are produced in the form of wire, rods and sheets, which are subsequently used, for example, in the production of pipes.
• Cast alloys can be deformed only when exposed to high temperatures and significant pressure. This technology is used to make automotive parts, bearings, etc.

Brass production

Obtaining this metal alloy is a very complicated procedure. The bottom line is that copper, zinc and other elements have different melting points, and therefore brass is produced in several stages. The same applies to additives for alloying: substances must be added in a strict sequence, while some of them require the use of a flux.

The production algorithm is directly dependent on the type and structure of brass. Casting materials in the form of ingots are used to cast a wide variety of parts. Wrought-type alloys are sent straight to the rolling mill, where they are annealed, machined and pickled.

The general production scheme is as follows:

Scope of use

The scope of materials is directly dependent on their characteristics and properties.

brass for a long time used by professional jewelers. For example, the yellow alloy practically does not have any external differences from real gold 583. This alloy was considered a kind of "simulator" for novice jewelers, because it physical properties very close to the characteristics of gold. Now jewelry is often made of brass.

This type of alloy is also used in furniture production. Brass is easy to forge, which makes it possible to make the most original decorative elements on furniture. The same property allows you to make dishes, figurines, sconces and coasters from the material.

In addition, elements of chemical and heat engineering devices are made of brass: capillary tubes, coils, etc.

Shaped elements are made from cast-type alloy eg fittings.

Brass is used in a large number of industries, which is not surprising, because it has high corrosion resistance, low weight and aesthetic appearance.

brass properties

Good day, dear reader! This article will talk about brass about its application and properties. 2 thirds and 1 third zinc - this is the classic composition of brass. This is one that has been known since ancient Rome.

But after all, they opened it only in the 16th century, some will object. Officially, yes. But, unofficially, this element was known before. Only the Romans called him, or rather the zinc-containing rock, galmei.

Ancient people believed that it was he who colors copper yellow. Now it is known that zinc only dilutes the rich red color of copper with white. The result is solar material.

Apparently, brass was made in Rome in proportions of 30% zinc, 70% copper. There is also an option with a zinc content of 5 to 20 percent, but in this case the alloy is red. Types of brass even have designations. A capital L and percentages are put on the material. The latter indicate the content of copper in the alloy.

There are also brass alloys not from two, but from a greater number of components. In this case, after the letter L there are still capital letters. Each of them represents the added metal.

Among these are: -,,. They are added to increase the anti-corrosion properties of the material. Otherwise, brass could not be a "player", for example, in the shipping market. An alloy of classical composition wears out from salt water.

Application of brass

Brass is soft, easy to bend, yet durable. Since, outwardly, the metal resembles gold, it is widely used. The alloy becomes a material for dishes, accessories, jewelry, orders.

By the way, insignia are coated with an alloy with 15% zinc and 5% zinc. It is this formula that outwardly resembles gold as much as possible and, at the same time, is resistant to corrosion. In total, 3 types of brass are used in jewelry: - yellow (M 67/33), golden (M 75/25), green (M 60/40).

Alloy jewelry is cleaned with oxalic acid. It perfectly polishes the surface. You can buy "elixir" in ordinary stores of household goods. True, the acid must be diluted. 200 grams of the substance is stirred in 10 liters of water and, only then, cleaned brass products.

Masters call brass "the eternal metal". of it do not know demolition. It does not apply to precious metal, and therefore earrings, bracelets, rings from it, only jewelry. However, some alloy products are high-status and cost decent money.

So, the bodies of the famous Zippo lighters are mostly brass. In the town of Brandford, Pennsylvania, where the plant is located, more than 60,000 lighters are produced per day. Since they contain copper and zinc, the products are yellow. They are given a steel color by galvanization, that is, spraying silvery shades onto the surface of other metals.

two piece brass with the maximum copper content is used for coils, machine parts, technical equipment. Bolts, nuts, screws are made of an alloy with an average content of red metal.

Multi-component brass is useful in the manufacture of aircraft, watercraft, pipes (including for refrigeration equipment), clocks, springs, fittings, separators. The alloy is also useful in printing. They make matrices for printing out of brass.

But how is the alloy itself made? First melt the copper. The metal is placed in refractory clay tanks. Those, in turn, are put into special industrial furnaces. Zinc is added to liquid copper to taste. They throw him in pieces.

That's the whole technology. The fuel is usually coal. For forms where cast brass buy sand. If thin sheets of alloy are needed, the mixture is poured into metal containers called molds.

The volatility of zinc became a snag in the manufacture of the metal. When melted, it simply evaporates. We have to use special devices that condense the vapor and return the element to the alloy.

About a third of the resulting metal is sent for remelting. The fact is that when molded, brass shrinks strongly, deflections and cavities (shells) are formed.

They are cut and sent for recycling. Finished brass softens at a temperature of at least 800 degrees Celsius. Minimum bar with a high content of Zn in the alloy. The smaller it is, the higher the melting bar. Such brass with high copper content(about 90%) call tompak.

In Russia, the following specialize in the production of brass:

— Krasnoyarsk enterprise KRAMZ

— Samara plant secondary alloys

— Uralelectromed from Verkhnyaya Pyshma

— Moscow groups of companies Elekmed, Nermet, Delta

— metropolitan enterprises Metallocommerce and Intermetallic

Externally, brass resembles bronze. By the way, zinc alloy is pushing the latter out of the interior market. Bronze faucets and fittings in stores, and therefore at home, are being replaced by brass ones. They are easier to polish and easier to maintain. plumbing brass often made with impurities or coated with special compounds. This is done to paint the metal in unusual colors. So, black brass taps are in trend.

They began to forge headboards from the alloy. They look light, airy, which is in the hands of the owners of small bedrooms. The aesthetic appeal of forged furniture is also important. Brass also captured the market for lamps and kitchen hoods.

metal brass recognized by the world community as the most important copper alloy. As you can see, it has found application almost everywhere. Is that the printed word, so far, brass is not subject.

Although, the letters on the pages of books and documents are also an alloy, only lead and tin. It is from this composition that fonts are made in printing houses.

We sell hire from brass alloys wholesale and retail. There are 245 products in the catalog, located in 6 categories. Shipment of products across the territory of Russia, convenient system of payment and order.

Brass Cu - Zn, a yellow metal, a double or multicomponent copper-based alloy, with an alloying component of zinc, sometimes with tin (in smaller proportions, or tin bronze will turn out), nickel, lead, manganese, iron and other elements. According to the metallurgical classification, it does not belong to bronzes. Density 8300-8700 kg/m³. The specific heat capacity at 20 °C is 0.377 kJ kg−1 K−1. Specific electrical resistance - (0.07-0.08) 10−6 Ohm m. The melting point of brass, depending on the composition, reaches 880-950 °C. As the zinc content increases, the melting point decreases. Brass is welded by gas and arc welding in shielding gases, and is also rolled. The surface of brass turns black in air, to avoid this, the metal is varnished.

The brass alloy is denoted by the letter "L", followed by the letters of the incoming elements that form the alloy. In deformable grades, the first two digits after the letter "L" indicate the percentage of copper. For example, L63 is brass with 63% copper Cu. In the case of alloyed deformables, letters and numbers are also indicated indicating the name and amount of the alloying element, LAZh60-1-1 means brass with 60% Cu, alloyed with aluminum (A) in an amount of 1% and iron (G) in an amount of 1%. The Zn content is determined by the difference from 100%. In foundry brasses, the average content of the alloy components in percent is placed immediately after the letter with the name.

Wrought double brass

Wrought multi-component brasses