What is the name of the alloy of copper and zinc

Characteristics and application of brass - an alloy of copper and zinc

Surely many people know what brass is. And many people know that this is an alloy of copper and zinc, which additionally contains a number of other elements - iron, lead, manganese, nickel, etc. However, zinc plays a key role in this alloy.

Characteristics of copper alloy with zinc content

The alloy of copper and zinc is characterized by properties such as corrosion resistance and high strength. The level of corrosion resistance of brass is in the middle of the values of this parameter for copper and the second metal – zinc.

The use of a copper-zinc alloy in the production of products of complex shapes, but with small geometric dimensions, is justified by its technological properties. Such a material (like copper and other types of its alloys) is easily shaped, and finished products made from it can easily be processed using various methods.

Types of brass depending on zinc content

Brass is characterized by high fluidity and a slight tendency to segregation, which makes it an ideal material for the production of various parts by casting. In addition, brass lends itself well to processing by plastic deformation, which makes it possible to produce various products from it by rolling (wire, strips, sheets, rolled products of various profiles).

Zinc can be contained in brass in an amount of 5–45%; according to this parameter, the alloy can fall into different categories. The first category is yellow brass (they contain 20–36% zinc), the second is red (they contain zinc from 5 to 20%). A type of alloy called tombak contains up to 10% zinc. There are brasses that contain more than 45% zinc, but their use is very limited.

Copper alloys (including those with zinc) are characterized by lower thermal and electrical conductivity when compared with the base metal, but their cost is also much lower. Considering this fact, as well as the fact that in terms of the main characteristics - mechanical, technological, as well as anti-friction - such materials are not much different from the base metal, it is more economically feasible to use them.

Brass consisting of two or more components

Among the alloys of copper and zinc, not only red and yellow, but also two- and multi-component brasses are distinguished. The composition of two-component alloys consists mainly of copper and zinc, with very few other inclusions. This, in particular, includes tombac, which, as noted above, contains no more than 10% zinc. The amount of copper in such an alloy can reach up to 97%, and its minimum content is 88%.

Two-component brasses can be single-phase or two-phase. In single-phase, characterized by high plasticity, zinc is present in a state of solid solution. If we compare single-phase and two-phase brass, the latter are less ductile, but have greater strength; such alloys contain more than 39% zinc.

Both single-phase and two-phase brasses cannot be subjected to deformation at high temperatures (300–700 degrees Celsius). Under such conditions, a zone of fragility is formed in them.

The structure of a copper-zinc alloy, which belongs to the multicomponent category, contains additional alloying elements. Let's list them.

Nickel increases the corrosion resistance of the alloy, as well as its strength.
Tin increases not only the strength, but also the resistance of the alloy to salt water.
The alloy is enriched with silicon in order to improve the antifriction characteristics of products made from it. However, this element degrades the strength as well as the hardness of alloys.
Lead, when added to an alloy, significantly improves the machinability of products made from it using cutting tools. Meanwhile, lead worsens the mechanical characteristics of the alloy.
Manganese, like tin, improves the strength and corrosion resistance of alloys. As a rule, along with manganese, tin, iron and aluminum are added to brass, which significantly increases the effect of using this alloying element.
By combining alloying elements added to brass, it is possible to obtain copper alloys with the required quality and technological characteristics, as well as give them special properties, if necessary.

Marking of alloys consisting of copper and zinc

The marking of copper alloys that contain zinc is based on a fairly simple principle. In the designation of any alloy of copper and zinc (both two- and multi-component) there is the letter “L”, which comes first. In two-component alloys, this letter is followed by numbers indicating the copper content in whole percentages. Thus, from this figure you can immediately find out what percentage of copper is contained in a given brand of brass.

Multi-component brass is distinguished by more complex markings, the designation of which contains several letters and numbers at once. The first letter is “L”, by which it becomes clear that this is brass; this letter is followed by the letter designations of various alloying elements.

The second part of the marking of multicomponent alloys is the percentage of alloying elements indicated in the letter part of the marking. For greater convenience, the numbers corresponding to the content of each alloying element are separated by hyphens.

The order of numbers in the marking of multi-component brasses is as follows:

the first two-digit figure is the copper content;
the remaining numbers, separated by hyphens, correspond to the content of alloying elements indicated in the letter part of the marking.

Reminder for marking brass

To make it more clear, let’s look at what elements are contained in the LAZhMts66-6-3-2 copper-zinc alloy. According to the first figure, this alloy contains 66% copper, followed by Aluminum (6%), Iron (3%) and Manganese (2%). If we sum up these figures, we can determine that this brass contains 77% copper and other elements. The remaining 23% is zinc.

Brass belonging to the foundry category is marked somewhat differently. In their markings, immediately after the letters indicating alloying elements, numbers are placed corresponding to their percentage content. For example, the LTs40Mts1.5 alloy contains:

40% zinc;
1.5% manganese;
the remaining 58.5% is copper.

Brasses classified as wrought and cast alloys

Brasses, which belong to the category of wrought alloys, are characterized by increased resistance to corrosion, they are very ductile and have exceptional anti-friction characteristics.

Alloys of copper and zinc in this category are well welded with steel products. This property makes it possible to use them for the production of various bimetallic structures.

Yellow brass has an attractive appearance, which is why it is often used for the production of various fittings and decorative items.

Brasses belonging to the category of wrought alloys are used for the production of:

condenser pipes (for these purposes, brass grades LMsh68-0.05, LO60-1, LO62-1, LO70-1, LO90-1, LA77-2 are required);
parts of machines, river and sea vessels with increased corrosion resistance (brass grades L68, L80, L90 are used here);
parts that are produced by cutting (for the production of such parts, brass grade LZhS58-1-1 is used);
various bushings, fasteners - bolts, nuts, etc. (for the production of such products, brass grades LS59-1, LMts58-2, LS60-1 are used);
matrices that are used in the printing industry (such products require brass grade LS64-2).

Composition and properties of various types of brass

Brasses belonging to the category of casting alloys are used for the production of such products as:

fittings used to equip hydraulic systems of automobiles (LTs25S2);
bearings and separators of various types (LTs40S);
worm-type screws having large dimensions and weight (LTs23A6Zh3Mts2);
parts with special properties that are operated at temperatures exceeding 300 degrees Celsius (LTs40Mts3Zh);
parts that are subject to increased requirements for corrosion resistance (LTs30A3).

Source: http://met-all.org/cvetmet-splavy/latun/latun-splav-medi-s-tsinkom.html

Brass is an alloy of copper and zinc. Main properties, composition and areas of application:

Brass is one of the most popular and widely used materials. It is used to make plumbing and construction parts, jewelry and exquisite decorative items. Its composition is an alloy of copper and zinc, with various admixtures of other elements. The components of brass affect its characteristics and determine the applications in which it is used. Let's find out what it is like.

Copper alloy

Copper is a soft red-pink metal with good thermal conductivity, ductility, malleability and resistance to oxidation in air. But due to a number of disadvantages, it is rarely used in its pure form and, as a rule, is alloyed with other metals.

An alloy of copper and zinc makes it possible to obtain a brass material that is easy to cut and has high mechanical strength and castability. It is cheaper and more versatile in use, and is also the second most common after bronze.

Brass is 55-95% copper and 5%-45% zinc. If it includes only these two components, then it is called simple or double. Brass, which includes other alloying elements, is multicomponent or special.

Depending on the chemical composition, the alloy comes in different shades - from dark yellow to yellow-red and white. In any case, it has good fluidity, slight shrinkage and segregation, and lends itself well to rolling, forging and other types of processing. Its corrosion resistance is higher than that of pure copper, but its electrical conductivity is slightly lower. Melting temperatures also strongly depend on the composition and range from 880-950 degrees Celsius.

Brass is prepared in low frequency induction furnaces. First, heat the copper to red heat, and then drop solid zinc into it. To prepare a special alloy of zinc and copper, pieces of other metals are also added secondarily, after the main component.

Copper to Zinc Ratio

There are more than 30 varieties of brass. Their characteristics can vary greatly, depending on the composition and proportions of the elements of a particular alloy. The main component is always copper. The more it is, the more ductile the brass and the higher its ability to conduct heat and electricity. With an increase in the amount of zinc, the alloy becomes harder and stronger, but its ductility is lost. When its content exceeds 45%, brass becomes brittle and is easily destroyed during processing.

The most ductile alloys consist of copper and zinc in a ratio of 70%/30%, 69%/31% or 68%/32%. When the amount of copper reaches 88-97%, and zinc - up to 10%, this mixture is called tompak. It is characterized by high antifriction properties, good ductility and resistance to oxidation in air. Alloys where zinc makes up 10-30% are called semi-solid alloys.

Alloying brass

Often a simple alloy of copper and zinc contains minor impurities of other elements. However, their number is very small, so this is not reflected in its characteristics. But it happens that other components are added to the alloy specifically to change its properties and make it more suitable for certain types of processing.

The alloying elements of brass, as a rule, are aluminum, iron, tin, manganese, nickel, lead, and their content ranges from 0.5% to 3%. When combined with nickel, the alloy of copper and zinc becomes very light and acquires significant resistance to high humidity.

The tin makes it resistant to salt water and allows it to be used in the sea or ocean. Thanks to lead, it lends itself well to cutting, forming even, very brittle chips, but it becomes less ductile.

Silicon makes the alloy less hard and durable, but it increases its anti-friction properties.

Marking

All products made from an alloy of copper and zinc have markings that help determine its composition. Its principle is quite simple: letters indicate the elements present, and numbers indicate their percentage.

Absolutely always the first letter is the capital letter “L”, indicating that this alloy is brass. If the composition is two-component, then only one number follows, indicating the amount of copper. In this case, zinc is determined by the remainder of 100%.

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In a multicomponent alloy, the letter “L” is followed by the letters of the alloying elements. Next come the numbers: the first indicates the amount of copper, and the rest, separated by a hyphen, show the content of other components, in the same order in which the letters are located.

Application

Several centuries ago, merchants successfully passed off brass as real gold by selling jewelry made from it. Today the range of its application is much wider. Thanks to its beautiful dirty yellow hue, it looks very attractive and even noble, so it is used to make jewelry, decorative items, various souvenirs, lamps, washbasins and basins for the bathroom, consoles, and door handles.

Alloys of copper and zinc grades L62 and L68 are very close to gold in their mechanical properties, so they are used in jewelry for training. Medals and various awards are made from tombaks, covering them with a layer of gold on top. They are also suitable for musical wind instruments, the manufacture of parts for watch movements and accessories. When combined with steel or rare metals, bimetallic products are obtained from them.

In industry, brass is used for fittings, radiator tubes, generator bushings, faucets and other parts that are used in the automotive industry. In the form of sheets, wires, circles and rods, it is also used in printing, instrument making, machine tool production and electrical engineering.

Source: https://www.syl.ru/article/409853/latun---splav-medi-i-tsinka-osnovnyie-svoytva-sostav-i-oblasti-primeneniya

What is the alloy of copper and zinc called?

Education March 18, 2017

A huge part of the mined metals is used in industry in the form of alloys. They learned to make them even before our era. What are alloys? What is the name of the alloy whose base is copper and zinc? Where is it used? The answers to these questions are in the article.

What are alloys?

Alloys are materials made from a mixture of several metals and other elements. They may contain random admixtures of natural components. One of the first known alloys was bronze. Man created 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, a small proportion of nickel, platinum, zinc or silver is added to it.

By mixing several components, you can change the properties of the metal, increase the melting point and malleability, impart strength and hardness, and increase wear resistance. The most common alloys are bronze, brass (an alloy of copper and zinc), cast iron, steel, Babbitt, Pobedit, and 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 formerly used to make cutlery, and cast iron was widely used to make household items such as frying pans and irons.

Copper-zinc alloy

A mixture of copper and zinc is called brass. Like bronze, it appeared before our era. Since then, its manufacturing technology has changed somewhat. In the past, copper was mixed with charcoal and zinc ore to make brass. In the 18th century, Englishman James Emerson proposed mixing the metals themselves without the use of ore.

The base of brass is copper. zinc varies from 5 to 45 percent. Because of its yellowish color, reminiscent of gold, in ancient Rome brass was called orichalcum, which literally means “golden copper.”

The alloy of copper and zinc is not always limited to only these metals. It may contain some tin, lead, iron, manganese, nickel and other components. If you add more tin than zinc, you get a completely different material - tin bronze.

Properties of brass

Depending on the amount of zinc, the color and quality of brass varies. The less it is, the more red and saturated the color of the material. 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 up to 20%) and yellow brass (zinc from 20%).

The material brass is very ductile and exhibits greater resistance to corrosion than copper. The melting point ranges from 880°C to 950°C, decreasing with larger proportions of zinc. The metal lends itself well to welding, rolling and pressure processing.

Yellow brass cracks when exposed to humid air. This can be corrected by annealing at a temperature of 250 °C. Multi-component brass resists corrosion better and is stronger. Adding tin to the composition promotes resistance to sea water.

impurities in the alloy can be found on the product labeling. Capital letters indicate the names of the components. First comes the letter “L”, then the remaining additional (alloying) elements. After them, the percentage content of substances is indicated in accordance with the letter order, with the first two digits indicating the amount of copper in the alloy. Thus, the marking LAZH60-1-1 means that brass consists of 60% copper, 1% aluminum and 1% iron, the rest is zinc.

Where is brass used?

Brass has good heat capacity. It is no coincidence that samovars were made from it in Ancient Rus'. In Rome, under Octavian Augustus, coins of sestertia and dupondium were minted from brass. In the Middle Ages, it was used to make jewelry, frame compasses, and decorate objects of art.

And now the material is used everywhere. Jewelry and small interior items are made from brass. A special artificial aging technique gives brass products a special charm. Figurines, door handles, and 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. The alloy with lead is used for cars and watches, tombac is used for cladding steel and making radiator pipes. Insignia are made from a composition containing 0.5% aluminum, as it has a golden hue.

Source: https://monateka.com/article/178179/

Characteristics and uses of brass, which is an alloy of copper and zinc

Metallurgy and metalworking are the basis of the existence and development of human civilization, since it was the beginning of the extraction and use of metals in everyday life that caused the evolution of society from the Stone Age to more developed forms.

A special place in metallurgy is occupied by the creation of alloys, evidence of which is bronze, which became the basis for the emergence of the concept of the “Bronze Age”. An alloy is a mixture of several chemical elements that give the final product certain properties. There is a huge variety of alloys and methods for creating them.

Of particular importance in this list is an alloy of zinc and copper, also called brass.

Brass has been known since the beginning of the new era and was first produced in the Roman Empire, but was also used in India and China. Later, the method of smelting zinc was lost in Europe, so for a long time the metal was imported from Asia. Zinc mining in Europe resumed in the 16th century, and brass smelting began in the 19th century.

Thanks to archaeological excavations, it is known that brass was widely used for jewelry, as it has the characteristic yellow color of gold and is called “fake gold.”

With the development of metallurgy, the alloy expanded its scope of application, which was ensured by regulating the characteristics of the metal by varying the ratio of its components.

Properties of copper and zinc alloy

There are several types of brass, which are characterized by both general properties and individual ones. Main characteristics:

metal density - from 8.2 to 8.7 t/m3;
heat capacity - 380 J/(kg*K);
electrical resistance - from 0.025 to 0.108 Ohm*sq. Mmm;
melting point - from 870 to 990 degrees.

Both main elements have a relatively high density. Accordingly, their connection is characterized by high mass. Brass is easily processed by arc welding, but will not respond to gas welding. It oxidizes quickly, so if necessary, the metal is coated with varnish or polished. Zinc provides strength and ductility. The latter can be regulated by zinc content.

Certain properties are imparted by alloying additives, which change the composition of brass and allow its characteristics to be adjusted over a wide range. A feature of the additives is the absence of changes in the specific gravity of the alloy.

The addition of magnesium increases strength and anti-corrosion qualities. Nickel reduces oxidation and lead improves ductility. If you add silicon without other additives, the ductility and strength will increase.

There are many combinations of zinc, copper and additive ratios that provide the desired performance.

zinc in the metal can vary from 5 to 45 percent. With a zinc content of up to 20 percent, brass is called red or tombak, and above 20% - yellow. An alloy containing only zinc and copper is two-component, while an alloy containing additives is multi-component. According to the scope of application, brass can be divided into casting, wrought, and automatic.

Regarding the composition of the metal, it is marked according to GOST standards. Brass by qualification is designated by the letter “L”, then there are designations of additives with numbers that indicate the percentage of copper and additives.

For example, LO70−1, where 70% is copper, 1% is tin and, accordingly, zinc is not indicated, of which there is 29% . Casting alloys have a different marking: the quantitative content is indicated after the letter, and zinc is indicated instead of copper.

For example, the marking of the above alloy has been redone - LTs29O1.

Areas of use of alloys

The annual smelting of the alloy amounts to more than two million tons, while half is made from recycled materials. Depending on the scope of application, brass is divided into:

wrought - alloys with a zinc content of less than 10%, which provides ductility, pressure treatment, corrosion resistance and a low level of friction with other metals. Characteristic appearance is “gold”;
foundry - alloys with a zinc content of 20 to 45 percent. Used for casting pipes, wires, angles and other products that will be exposed to aggressive influences. Characterized by ductility, strength and stability;
automatic, containing lead, which ensures automatic processing of brass products on machines.

Stamping of deformable products is widely used in shipbuilding, mechanical engineering, aviation, as well as decoration and the manufacture of cultural objects. Foundry production provides kilometers of rolled products annually, and automatic production produces screws, bolts, nuts, etc. Making jewelry from brass has been known since antiquity. Brass is used in all spheres of society, and it is impossible to abandon it in the near future.

Source: https://tokar.guru/metally/splavy/proizvodstvo-i-ispolzovanie-splava-medi-i-cinka.html

An alloy of copper and lead is called

Copper belongs to the group of non-ferrous metals most widely used in industry. The serial number of copper in the periodic system of D.I. Mendeleev is 29, atomic weight A = 63.57. Copper has a face-centered cubic lattice (fcc) with a period a = 3.607 Å.

The specific gravity of copper is g = 8.94 g/cm 3, the melting point is 1083 0 C. Pure copper has high thermal and electrical conductivity. The electrical resistivity of copper is 0.0175 μΩ×m, thermal conductivity l = 395 W/(m×deg).

Ultimate strength sв = 200250 MPa, hardness 85115 НВ, relative elongation d = 50%, relative contraction y = 75%.

Copper is a non-magnetic metal. It has good manufacturability: it can be processed by pressure, cutting, is easy to polish, is well soldered and welded, and has high corrosion resistance. The main area of application is the electrical industry.

The electrical conductivity of copper is significantly reduced in the presence of even very small amounts of impurities. Therefore, especially pure copper M00 (99.99%), electrolytic copper M0 (99.95%), and M1 (99.9%) are used as conductor materials. Technical copper grades M2 (99.7%), M3 (99.5%), M4 (99.0%).

Depending on the mechanical properties, a distinction is made between hard, cold-worked copper (MT) and soft, annealed copper (MM).

Harmful impurities in copper are bismuth, lead, sulfur and oxygen. The action of bismuth and lead is similar to the action of sulfur in steel; They form low-melting eutectics with copper, located along the grain boundaries, which leads to the destruction of copper when it is processed under pressure in a hot state (the melting point of the eutectic is 270 0 C and 326 0 C, respectively).

Sulfur and oxygen reduce the ductility of copper due to the formation of brittle chemical compounds Cu2O and Cu2S.

Technically pure copper is rarely used as a structural material, since it has low strength properties and hardness. The main copper-based structural materials are alloys of brass and bronze. To mark copper alloys, use the following letter designation of alloying elements:

O - tin; C - zinc; X - chromium;
F - iron; N - nickel; C - lead;
K - silicon; A - aluminum; F - phosphorus;
Mts - manganese; Mg – magnesium; B – beryllium.

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Brass

Brasses are copper alloys in which the main alloying element is zinc.

Depending on the zinc content, brasses for industrial use are:

single-phase a - brass containing up to 39% zinc (this is the maximum solubility of zinc in copper);
two-phase (a+b|)- brass containing up to 46% zinc;
single-phase b|- brass containing up to 50% zinc.

Single-phase a-brasses are ductile, can be easily processed by cutting and pressure at temperatures below 300 0 C and above 700 0 C (in the range from 300 0 C to 700 0 C - the brittle zone). With increasing zinc content, the strength of brass increases.

In brasses, the b|-phase is an ordered solid solution based on the electronic connection of CuZn with a bcc lattice; it is brittle and strong. Therefore, the more b|-phase in brass, the stronger and less ductile they are.

Brass with a zinc content of up to 4243% has practical application.

Brasses processed by pressure are marked with the letter L (brass), followed by the letter designations of alloying elements; The numbers following the letters indicate the copper content and the percentage of the corresponding alloying element. zinc is determined by the difference from 100%.

For example, L62 brass contains 62% Cu and 38% Zn. Casting brass is marked with the letter L, after which the content of zinc and other alloying elements is indicated as a percentage. The amount of copper is determined by the difference from 100%. For example, brass LTs36Mts20S2 contains 36% Zn, 20% Mn, 2% Pb and 42% Cu.

Single-phase a-brasses include L96 (tompak), L80 (semi-tompak), L68, which has the greatest ductility (d = 56%). Two-phase (a+b|) - brasses of grades L59 and L60 have less ductility in the cold state, but greater strength and wear resistance. Single-phase ones have after annealing sв = 250350 MPa and d = (5056)%, two-phase ones have sв = 400450 MPa and d = (35-40%).

To increase the mechanical properties and corrosion resistance of brass, they can be alloyed with tin, aluminum, manganese, silicon, nickel, iron, etc.

The introduction of alloying elements (except nickel) reduces the solubility of zinc in copper and promotes the formation of the b|- phase, therefore such brasses are often two-phase (a+b|). Nickel increases the solubility of zinc in copper, and with sufficient zinc content, brass changes from two-phase to single-phase. Lead facilitates machinability and improves anti-friction properties. Corrosion resistance is increased by Al, Zn, Si, Mn, Ni, Sn.

In marine shipbuilding, tin-bearing “marine” brasses are used, for example, LO70-1 (70% Cu, 1% Sn, 29% Zn). It is used for the manufacture of condenser tubes and parts of heating equipment.

Aluminum brasses are used for the manufacture of condenser tubes, tanks, bushings, as well as for the manufacture of corrosion-resistant parts operating in sea water. Brands of brass: LA77-2, LAZ60-1-1, LAN59-3-2 (in electrical machines, in chemical engineering). Solid-drawn round pipes are made from brass LANKMts75-2-2.5-0.5-0.5 for the production of pressure tubes and springs in instruments of a high accuracy class. With the help of hardening and aging, sв reaches 700 MPa.

Manganese brasses, in addition to good mechanical and technological properties (processed by pressure in cold and hot conditions), have high corrosion resistance in sea water, chlorides and superheated steam. Brasses LMts 58-2 and LMtsA 57-3-1 are used mainly for the manufacture of fittings and fasteners.

Silicon brasses are characterized by high strength (sv up to 640 MPa), ductility and toughness up to minus 183 0 C. LK80-3 brass is used for the manufacture of fittings and instrument parts in shipbuilding and general mechanical engineering.

Lead-bearing brass is excellent for cutting and has high anti-friction properties. Brasses LS60-1, LS59-1 are used for the manufacture of fasteners, gears, bushings.

Nickel brass has increased mechanical (sв up to 785 MPa) and corrosion properties, and is processed by pressure in a cold and hot state. Brass LN65-5 is used for the manufacture of manometric and condenser tubes, various types of rolled products.

Cast brasses contain the same elements as workable brasses; What distinguishes foundries from the latter are, as a rule, greater alloying with zinc and other metals. As a result, they have good casting characteristics.

Bronze

Bronzes are alloys of copper with tin, aluminum, silicon and other elements.

Based on technological characteristics, bronzes are divided into wrought and cast bronzes. The deformable ones are marked with the letters Br, after which the alloying elements are listed, and then, accordingly, the content of these elements in percentage. copper is determined by the difference from 100%. For example, BrOTsS 8-4-3 contains 8% Sn, 4% Zn, 3% Pb, 85% Cu.

Cast bronzes are marked similarly to cast brass. For example, bronze Br06Ts3N6 contains 6% Sn, 3% Zn, 6% Pb, 85% Cu.

Compared to brass, bronze has better mechanical, antifriction properties and corrosion resistance.

Tin bronzes. Alloys containing up to 1012% Sn are of greatest practical importance. The limiting solubility of tin in copper is 15.8%, however, under real conditions of crystallization and cooling, the limiting solubility decreases to approximately 6%.

Single-phase alloys include bronze with a tin content of up to 56% and a - phase, which is a solid solution of tin in copper with an fcc lattice. At a higher tin content, along with the a - solution, a eutectoid (a + Cu31Sn8) is present.

The tensile strength of bronze increases with increasing tin, but at high concentrations it decreases sharply due to the larger amount of brittle intermetallic Cu31Sn8.

Tin bronzes are usually alloyed with Zn, Pb, Ni, P. Zinc improves the technological properties of bronze and reduces its cost. Phosphorus improves casting properties. For the production of artistic castings, the phosphorus content can reach 1%.

Lead (up to 35%) is introduced into bronze to improve its machinability. Nickel increases the mechanical properties, corrosion resistance and density of castings, and reduces segregation.

Among copper alloys, tin bronzes have the lowest linear shrinkage (0.8% when cast in earth and 1.4% when cast in a metal mold).

To achieve plasticity, the alloys are homogenized at temperatures of 700-750 0 C with rapid cooling. Residual stresses are removed by annealing at 550 0 C.

Tin deformable bronzes Br0F7-0.2, BrOTsS4-4-4, BrOTs4-3 and others have higher strength, elasticity, and fatigue resistance than cast bronzes. They are used for the manufacture of sliding bearings, gears, tubes for control and measuring and other instruments, pressure springs, etc.

Foundry tin bronzes. Compared to deformable ones, they contain a larger amount of alloying elements, have lower fluidity, low linear shrinkage, and are prone to the formation of shrinkage porosity. Bronzes BrOZTS7S5N, BrO10F1, BrO6Ts6S3, BrO5S25 and others are used for the manufacture of fittings operating in water and steam, bearings, gears, bushings.

Aluminum bronzes are distinguished by high mechanical anti-corrosion properties, fluidity, and low tendency to dendritic segregation. Due to the large shrinkage, it is difficult to obtain complex shaped castings. They are frost-resistant, non-magnetic, and do not spark when struck. They are superior to brass and tin bronze in corrosion resistance.

Aluminum dissolves in copper, forming a - substitutional solid solution with a solubility limit of 9.4%. At higher contents, a eutectoid (a + g|) appears in the structure; g| — Cu32Al9 intermetallic compound.

Single-phase bronzes BrA5, BrA7 have good ductility and are classified as deformable. They have the best combination of strength and ductility: sв = 400450 MPa, d = 60%.

Two-phase bronzes (a + g|) have increased strength up to 600 MPa, but ductility is noticeably lower d = (3545)%. These alloys are strengthened by heat treatment and additionally alloyed with Fe, Ni, and Mn.

Source: https://vi-pole.ru/splav-medi-i-svinca-nazyvaetsja.html