What is zinc alloy

Where is it permissible to use zinc alloys and what are their properties?

In the 4th millennium BC. e. man first became acquainted with metal nuggets. Later he learned how to process it and make tools for solving everyday problems and weapons. Since then, people have continued to learn and improve in the methods of mining and processing metals. Zinc and zinc alloy played a key role in history.

Properties of zinc alloys

To understand what properties zinc alloys should have, you need to know the characteristics of zinc. Casting qualities, melting point, hardness and other parameters directly depend on the chemical and physical properties of zinc. It is a bluish metal. This substance is not found in natural deposits in its pure form. During long-term processing, zinc oxide is obtained, from which pure metal can be obtained.

Characteristics and properties of zinc

Before describing zinc alloys and their use in various areas of production, it is necessary to understand the properties of zinc.

Chemical properties:

1. When heated for a long time, it can react with H2O and hydrogen sulfide. In its process, hydrogen is released.
2. Does not come into contact with carbon and nitrogen.
3. Mixes with various non-metals - oxygen, phosphorus and sulfur.
4. When combined with alkalis, zincates are formed (these are salts of zinc acid).
5. When a metal is mixed with sulfuric acid, various substances can form. It all depends on the amount of acid.
6. At very high temperatures, the metal can come into contact with various gases (iodine in gaseous state, chlorine and fluorine).

Physical properties:

1. It is a durable metal. When heated to 100–150°C, it becomes plastic. When heated to more than 210 °C, the metal changes its shape. Compared to other metals, zinc melts at a low temperature.
2. It has good thermal conductivity - 116 W/m K.
3. The material boils at a temperature of 906°C.
4. Density - 7.133 g/cm3
5. Melting of the material - 419°C.
6. Maximum tensile strength is 200–250 MN/m2.
7. The specific heat of evaporation is 114.8 KJ/mol.

The amount of impurities in the metal directly depends on the method of extraction, processing and the original type of the material. Common impurities found in zinc are nickel, fluorine, chlorine and lead.

Lead and zinc are called an inseparable pair. Although lead is an impurity contained in zinc, they are not found together very often in deposits. A large amount of lead contained in the original material worsens its properties. Intergranular corrosion develops faster. To remove impurities of foreign metals, the distillation method is used.

How do impurities change the properties of zinc

Foreign impurities contained in zinc worsen the characteristics of this metal (at high contents). The primary goal of manufacturers is to reduce the amount of lead, cadmium and tin in this metal to avoid intercrystalline corrosion.

Impact of impurities on zinc:

1. Lead - increases the solubility of the metal in water.
2. Copper - worsens the ductility index. The metal becomes more vulnerable to corrosion, but its strength improves.
3. Arsenic - impairs the strength and ductility of zinc even at a minimum content.
4. Tin - increases the fragility of finished castings.
5. Cadmium - reduces the ductility of the metal.
6. Antimony - in the process of rolling at high temperatures, increases the strength and worsens the ductility of zinc.

Almost all impurities are considered harmful to finished products. Because of this, manufacturers first carry out a series of procedures to ensure that the zinc content in the finished casting is as high as possible.

Types of alloys

As technology developed, various zinc alloys emerged. The combination of two metals can be much better in performance than pure raw materials, refined and melted into blanks. Let's talk about the most famous alloys of zinc with other metals.

Copper and zinc

A derivative mixture of copper and zinc is brass. The alloy has been known since ancient times. It was originally made by smelting zinc ore and copper. In the 18th century An alloy with the addition of metallic zinc was first produced. There are 3 types of brass:

1. Green - 60% copper.
2. Golden - 75% copper.
3. Yellow - 67% copper.

In the past, brass was used to make coins and jewelry.

Steel and zinc

Everyone knows galvanized steel. It can be found in any apartment or workplace. It is unreasonable to call this mixture an alloy. A layer of zinc coating is applied to the steel sheet. At a temperature of 400°C, liquid zinc is applied to the steel surface. At this temperature, the atoms of the two metals are tightly bonded to each other and form an iron-zinc alloy. Galvanized surfaces do not rust.

Tin and zinc

An alloy of tin and zinc is popular in the electrical industry. Due to its high heat capacity, this alloy was used in the manufacture of vessels for storing liquids. Drinks remained warm for a long time.

Aluminum and zinc

Alloys of aluminum and zinc with the addition of other metals are used in foundries. The resulting mixture has good casting parameters due to its low melting point.

Is zinc alloy harmful?

With modern equipment, manufacturers have achieved a reduction in the amount of lead and nickel in alloys to a minimum. These metals carried a key danger to the human body. Due to their reduction in the composition of finished products, jewelry made from zinc alloys is considered safe for health.

Application

Nowadays, the use of zinc alloys with other metals can be seen in various industries.

To protect metals from corrosion

To protect other metals from corrosion, a clean material is used to cover the vulnerable surface. The coating process is called metallization.

In the automotive industry

Zinc and alloys containing it have gained great popularity in the automotive industry. Mixtures of metals are used for decorative coating of individual elements of the car (handles, bumpers, grilles, mirrors). Gear mechanisms, lever mechanisms, tires, batteries contain this substance.

In the production of jewelry

Costume jewelry and decorations made of zinc alloys have been known for a long time. Zinc is often mixed with gold. This metal is also used to make white gold. It brightens the finished product.

In construction

Alloys of zinc and other metals are widely used in construction. For example, they are used in the production of roofing. Not only the roofing covering is made from galvanization, but also various pipes, gutters, wind strips, and lining for roof overhangs.

In medicine

When it comes to medicine, zinc oxide is often used as an antiseptic. It is also added to formulations used to accelerate regeneration.

Use of zinc in medicine

How alloys are made

Before understanding the production of alloys, it is necessary to understand how pure metal is obtained.

The most famous method is distillation. First of all, the concentrated composition is fired. It is then heated until a grainy texture is achieved.

After this, the concentrated substance is reduced with the help of coal when heated to 1300°C. The vapors produced in this process are condensed and poured into molds. Next, the liquid metal settles at a temperature of 500°C.

Lead and iron come out of it. After the distillation process, the material obtained is 98–99% pure.

There is also a more complex and expensive processing method - rectification. During this process, heat exchange occurs between liquid and steam. Heat exchange separates mixtures and eliminates impurities. The output is material with a purity of 99–99.9%.

There is another method for producing pure material - electrolytic.
After roasting the concentrate, it is treated with sulfuric acid. The resulting substance is purified from impurities and undergoes the process of electrolysis (produced in lead baths). The metal remains in the baths, which is melted using induction furnaces. The resulting material is 99.95% pure. How to get zinc for free

Obtaining zinc by electrolysis
After obtaining the pure material, it is melted. Other substances are added to the liquid metal to improve its technical characteristics. The better the metal is heated, the better it will fill the molds.

Zinc alloys are used in various industries, jewelry making and medicine (oxide). Galvanized sheets and materials made from them are popular in construction. When purchasing an alloy, it is important to clarify the lead and nickel content in its composition.

These 2 substances are harmful to human health.

Source: https://metalloy.ru/splavy/tsinkovyj

Properties of zinc: chemical and physical, history of production and application, melting point and density - Machine

Zinc is a metal that is number 30 on the periodic table and has the designation Zn. It melts at a temperature of 419 °C, but if the boiling point is 913 °C, it begins to turn into steam. At normal temperatures, the condition is fragile, but at one hundred degrees it begins to bend.

The color of zinc is blue-white. When exposed to oxygen, oxidation occurs, as well as a coating of carbonate, which protects the metal from further oxidation reactions. The appearance of hydroxide on zinc means that water has no effect on the chemical element.

Zinc is a chemical element that has its own distinctive properties, advantages and disadvantages. It is widely used in human daily life, in pharmaceuticals and metallurgy.

Zinc

Features of zinc

Metal is necessary and widely used in almost all areas of daily human life.

Mining is mainly carried out in Iran, Kazakhstan, Australia, and Bolivia. In Russia, the manufacturer is OJSC GMK Dalpolimetal.

It is a transition metal, has an oxidation state of +2, a radioactive isotope, a half-life of 244 days.

Aqueous cadmium, zinc and copper arsenate

The element is not mined in its pure form. Contained in ores and minerals: cleiophane, marmatite, wurtzite, zincite. It is necessarily present in an alloy with aluminum, copper, tin, and nickel.

Chemical, physical properties and characteristics of zinc

Zinc is a metal that has a number of properties and characteristics that distinguish it from other elements of the periodic table.

The physical properties of zinc include its state. The main factor is temperature.

If at room temperature it is a brittle material, the density of zinc is 7130 kg/m3 (˃ the density of steel), which practically does not bend, then when raised, it easily bends and is rolled into sheets in factories.

If you take a higher temperature regime, the material acquires a liquid state, and if you raise the temperature by 400-450 °C degrees, then it will simply evaporate. This is uniqueness - changing your condition. If exposed to acids and alkalis, it can crumble, explode, or melt.

Liquid zinc

The formula of zinc is Zn – zinc. The atomic mass of zinc is 65.382 amu.

Electronic formula: the nucleus of a metal atom contains 30 protons, 35 neutrons. There are 4 energy levels in an atom - 30 electrons. (Fig. structure of the zinc atom) 1s22s22p63s23p63d104s2.

The crystal lattice of zinc is a hexagonal crystal system with tightly pressed atoms. Lattice data: A=2.66U, C=4.94.

Mined and not processed material has isotopes 64, 66, 67, electrons 2-8-18-2.

In terms of application, among all the elements of the periodic table, the metal ranks 23rd. In nature, the element appears in the form of sulfide with impurities of lead Pb, cadmium Cd, iron Fe, copper Cu, silver Ag.

Zinc sulfide

Depending on the amount of impurities, the metal is marked.

Zinc production

As mentioned above, there is no pure form of this element in nature. It is mined from other rocks, such as ore - cadmium, gallium, minerals - sphalerite.

The metal is obtained at the factory. Each plant has its own distinctive production features, so the equipment for obtaining pure material is different. It could be like this:

• The rotors, located vertically, are electrolytic.
• Special furnaces with a sufficiently high temperature for firing, as well as special electric furnaces.
• Conveyors and baths for electrolysis.

Depending on the metal mining method adopted, the appropriate equipment is used.

Obtaining pure zinc

As mentioned above, there is no pure species in nature. It is mainly extracted from ores in which it comes with various elements.

To obtain pure material, a special flotation process with selectivity is used. After the process, the ore breaks down into elements: zinc, lead, copper and so on.

The pure metal extracted by this method is fired in a special furnace. There, at certain temperatures, the sulfide state of the material turns into oxide. During roasting, gas containing sulfur is released, which is used to produce sulfuric acid.

Pure zinc

There are 2 ways to obtain metal:

1. Pyrometallurgical - the burning process takes place, after which the resulting mass is restored with the help of black coal and coke. The final process is settling.
2. Electrolytic – the extracted mass is treated with sulfuric acid. The resulting solution is subjected to electrolysis, during which the metal settles and is melted in furnaces.

Smelting zinc in a furnace

The melting temperature of zinc in a furnace is 419-480 °C degrees. If the temperature is exceeded, then the material begins to evaporate. At this temperature, an admixture of iron of 0.05% is allowed.

At an iron interest rate of 0.2, the sheet cannot be rolled.

Various methods are used for smelting pure metal, up to the production of zinc vapor, which is sent to special tanks and there the substance falls down.

Application of metal

The properties of zinc allow its use in many areas. As a percentage:

1. Galvanizing – up to 60%.
2. Medicine – 10%.
3. Various alloys containing this metal 10%.
4. Tire production 10%.
5. Paint production – 10%.

Copper-zinc alloy

The use of zinc is also necessary for the restoration of metals such as gold, silver, and platinum.

Zinc in metallurgy

The metallurgical industry uses this element of the periodic table as the main one to achieve certain goals. The smelting of cast iron and steel is the main one in the entire metallurgy of the country. But these metals are susceptible to negative environmental influences. Without certain treatment, metals rapidly oxidize, which leads to their deterioration. The best protection is galvanizing.

Applying a protective film to cast iron and steel is the best remedy against corrosion. About 40% of the total production of pure material is spent on galvanizing.

Galvanizing methods

Metallurgical plants are distinguished not only by their equipment, but also by the production methods used. It depends on the pricing policy, and location (natural resources used for the metallurgical industry). There are several galvanizing methods, which are discussed below.

Hot galvanizing method

This method involves dipping a metal part in a liquid solution. It happens like this:

1. The part or product is degreased, cleaned, washed and dried.
2. Next, the zinc is melted to a liquid state at temperatures up to 480 °C.
3. The prepared product is lowered into the liquid solution. At the same time, it is well wetted in the solution and a coating up to 450 microns thick is formed. This is 100% protection against the effects of external factors on the product (moisture, direct sunlight, water with chemical impurities).

Hot galvanizing of metal structures

But this method has a number of disadvantages:

• The zinc film on the product results in an uneven layer.
• This method cannot be used for parts that meet exact standards according to GOST. Where every millimeter is considered a defect.
• After hot-dip galvanizing, not every part will remain strong and wear-resistant, since brittleness appears after passing through high temperatures.

This method is also not suitable for products coated with paints and varnishes.

Cold galvanizing

This method has 2 names: galvanic and electrolytic. The method of coating a product with corrosion protection is as follows:

1. The metal part, the product is prepared (degreased, cleaned).
2. After this, the “staining method” is carried out - a special composition is used, which has the main component - zinc.
3. The part is coated with this composition by spraying.

Cold galvanizing

Thanks to this method, parts with precise tolerances and products coated with paints and varnishes are protected. Increases resistance to external factors leading to corrosion.

Disadvantages of this method: thin protective layer - up to 35 microns. This results in less protection and shorter protection periods.

Thermal diffusion method

This method makes a coating that is an electrode with positive polarity, while the metal of the product (steel) becomes negative polarity. An electrochemical protective layer appears.

The method is applicable only if the parts are made of carbon steel, cast iron, or steel with impurities. Zinc is used in the following ways:

1. At temperatures from 290 °C to 450 °C in a powder medium, the surface of the part is saturated with Zn. Here, the marking of the steel, as well as the type of product, matter - the appropriate temperature is selected.
2. The thickness of the protective layer reaches 110 microns.
3. A product made of steel or cast iron is placed in a closed tank.
4. A special mixture is added there.
5. The last step is special treatment of the product to prevent the appearance of white efflorescence from salt water.

Thermal diffusion galvanizing

This method is mainly used when it is necessary to coat parts that have a complex shape: threads, small strokes. The formation of a uniform protective layer is important, since these parts undergo multiple exposures to external aggressive environments (constant moisture).

This method provides the highest percentage of product protection against corrosion. Galvanized coating is wear-resistant and practically indestructible, which is very important for parts that are rotated and disassembled over time.

Other uses of zinc

In addition to galvanizing, the metal is also used in other industries.

1. Zinc sheets. To produce sheets, rolling is performed, in which ductility is important. It depends on the temperature. A temperature of 25 °C gives plasticity only in one plane, which creates certain properties of the metal. The main thing here is why the sheet is made. The higher the temperature, the thinner the metal becomes. Depending on this, the product is marked Ts1, Ts2, Ts3. After this, various products for cars, profiles for construction and repair, for printing, and so on are created from the sheets.
2. Zinc alloys. For improved properties of metal products, zinc is added. These alloys are created at high temperatures in special furnaces. The most commonly produced alloys are copper and aluminum. These alloys are used for the production of bearings and various bushings, which are applicable in mechanical engineering, shipbuilding and aviation.

In household use, a galvanized bucket, trough, and sheets on the roof are the norm. Zinc is used, not chromium or nickel. And it’s not just that galvanizing is cheaper than coating with other materials. This is the most reliable and long-lasting protective material than chrome or other materials used.

As a result, zinc is the most common metal widely used in metallurgy.

In mechanical engineering, construction, medicine, the material is used not only as protection against corrosion, but also to increase strength and long service life.

In private houses, galvanized sheets protect the roof from precipitation; in buildings, walls and ceilings are lined with plasterboard sheets based on galvanized profiles.

Almost every housewife has a galvanized bucket or trough in her house, which she uses for a long time.

Source: https://regionvtormet.ru/okrashivanie/svojstva-tsinka-himicheskie-i-fizicheskie-istoriya-polucheniya-i-primenenie-temperatura-plavleniya-i-plotnost.html

Zinc and its alloys - production, properties, types and applications

( 7, : 3.29)

Zinc is a brittle bluish-white metal. It is not found in nature without impurities. In 1738, William Champion obtained pure zinc vapor by condensation. In the periodic table of Mendeleev it is number 30 and is designated by the symbol Zn.

Chemical properties of zinc

Zinc is an active metal. At room temperature it fades and becomes coated with a layer of zinc oxide.

• Reacts with many non-metals: phosphorus, sulfur, oxygen.
• When the temperature rises, it reacts with water and hydrogen sulfide, releasing hydrogen.
• When fused with alkalis, it forms zincates - salts of zinc acid.
• Reacts with sulfuric acid, forming various substances depending on the concentration of the acid.
• When heated strongly, it reacts with many gases: chlorine gas, fluorine, iodine.
• Does not react with nitrogen, carbon and hydrogen.

Physical properties of zinc

Zinc is a hard metal, but becomes ductile at 100–150 °C. At temperatures above 210 °C it may become deformed. The melting point is very low for metals. Despite this, zinc has good electrical conductivity.

• Density - 7.133 g/cm³.
• Thermal conductivity - 116 W/(m K).
• The melting point of zinc is 419.6 °C.
• Boiling point - 906.2 °C.
• The specific heat of evaporation is 114.8 kJ/mol.
• The specific heat of fusion is 7.28 kJ/mol.
• Specific magnetic susceptibility - 0.175·10-6.
• Tensile strength - 200–250 MN/m2.

The detailed chemical composition of various grades of zinc is shown in the table below.

Brand designation	Zinc, no less	Impurity, no more
lead	cadmium	iron	copper	tin	arsenic	aluminum	Total
TsV00	99,997	0,00001	0,002	0,00001	0,00001	0,00001	0,0005	0,00001	0,003
CV0	99,995	0,003	0,002	0,002	0,001	0,001	0,0005	0,005	0,005
CV	99,99	0,005*	0,002	0,003	0,001	0,001	0,0005	0,005	0,01
Ts0A	99,98	0,01	0,003	0,003	0,001	0,001	0,0005	0,005	0,02
Ts0	99,975	0,013	0,004	0,005	0,001	0,001	0,0005	0,005	0,025
C 1	99,95	0,02	0,01	0,01	0,002	0,001	0,0005	0,005	0,05
Ts2	98,7	1,0	0,2	0,05	0,005	0,002	0,01	0,010**	1,3
Ts3	97,5	2,0	0,2	0,1	0,05	0,005	0,01	—	2,5
* In zinc used for the production of TsAM4-1o alloy, the mass fraction of lead should be no more than 0.004%. ** In zinc used for rolling, the mass fraction of aluminum should be no more than 0.005%.

impurities in zinc depend on the production method and the quality of the raw materials.

In Russia, the main percentage of zinc is obtained by the hydrometallurgical method - the metal is reduced from salts in solutions. This method allows you to obtain the purest metal. But some zinc is processed at high temperatures. This method is called pyrometallurgical.

Lead is a special impurity in zinc, since most of it is deposited due to insoluble anodes contained in the metal. Cathode zinc, in addition to all these impurities, consists of chlorine and fluorine.

Zinc alloys

Zinc-based alloys with the addition of copper, magnesium and aluminum have a low melting point and have good fluidity. They are easy to process, weld and solder.

Brass

There are two-component and multi-component brasses.

Two-component brass is a zinc alloy with a high copper content. There is yellow brass with copper in the amount of 67%, golden copper or tombac - 75%, and green - 60%. Such alloys can be deformed at temperatures of 300 °C.

Multicomponent brasses, in addition to the 2 main metals, consist of other additives: nickel, iron, lead or manganese. Each of the elements affects the properties of the alloy.

TsAM

TsAM is a family of zinc alloys. They contain magnesium, aluminum and copper. Such zinc alloys are used in foundries. They contain aluminum in the amount of 4%.

The main area of ​​application of TsAM alloys is zinc die casting. Alloys of this family have low melting points and good casting properties. Their high strength allows the production of durable and complex parts.

Virenium

The alloy consists of zinc (24.5%), copper (70%), nickel (5.5%).

Metal mining

Zinc as a native metal does not occur in nature. It is mined from polymetallic ores containing 1–4% metal in the form of sulfide, as well as copper, lead, gold, silver, bismuth and cadmium. The ores are enriched by selective flotation and zinc concentrates (50–60% Zn) are obtained.

Zinc concentrates are fired in furnaces. Zinc sulfide is converted to ZnO oxide. This releases sulfur dioxide SO2, which is used in the production of sulfuric acid.

Metal production

There are two ways to obtain pure zinc from ZnO oxide.

The most ancient method is distillation. The fired concentrated composition is subjected to heat treatment to give it granularity and gas permeability.

The concentrate is then reduced with coke or coal at a temperature of 1200–1300 °C. The process produces metal vapors, which are condensed and poured into molds. The liquid metal is separated from iron and lead at a temperature of 500 °C. This achieves zinc with a purity of 98.7%.

Sometimes complex and expensive processing of zinc by rectification is used - separation of mixtures due to the exchange of heat between steam and liquid. This cleaning allows you to obtain metal with a purity of 99.995% and remove cadmium.

The second method of producing zinc is electrolytic. The calcined concentrate is treated with sulfuric acid. The finished sulfate solution is cleaned of impurities, after which it is subjected to electrolysis in lead baths. Zinc deposits on aluminum cathodes. The resulting metal is removed from the baths and melted in induction furnaces. After this, electrolytic zinc with a purity of 99.95% is obtained.

Metal casting

Hot zinc is a liquid and flowing metal. Thanks to these properties, it is easily filled into molds.

Impurities affect the amount of surface tension of the zinc. The technological properties of the metal can be improved by adding small amounts of lithium, magnesium, tin, calcium, lead or bismuth.

The higher the overheating temperature of zinc, the better it fills molds. When casting metal into cast iron molds, its volume decreases by 1.6%. This makes it difficult to produce large and long zinc castings.

In medicine

Zinc oxide is used in medicine as an antiseptic. The oxide is added to ointments and other wound healing compounds.

Due to its properties, zinc is widely used in various industries. The metal is in demand due to its relatively low price and good physical properties.

Source: https://ferrolabs.ru/blog/tsink-i-ego-splavy/

Zinc alloys: GOST, melting point, properties, application:

Zinc is a bluish-white metal, which could not be obtained in its pure form for a long time. Only the Englishman J. Champion acquired a patent for its production in 1738. And five years later the first zinc plant appeared in Europe in Bristol. Its annual productivity was only 200 tons. In terms of use, this popular non-ferrous metal is second only to copper and aluminum. Millions of tons of it are smelted around the world every year.

Characteristics and properties of brass

A copper-zinc alloy in which copper is the main component and zinc is the alloying component is called brass. The color of the metal depends on the composition and varies from light yellow tones to reddish shades. Such alloys are characterized by resistance to corrosion and have high strength. They lend themselves well to various processing methods.

The fluidity of brass allows parts to be manufactured using the casting method. Using plastic deformation of the alloy, wire, sheets, tapes, and various profiles are produced from it by rolling. zinc in the alloy can vary and range from 5 to 45%.

In addition, it also includes additional alloying components that are used to improve the properties of brass:

• Nickel. Helps increase corrosion resistance and strength.
• Silicon. Improves anti-friction properties.
• Tin. Affects strength and resistance to salt water.
• Lead. Improves machinability.
• Manganese. Affects strength and corrosion resistance.

When various combinations of alloying components are used, brass with the required qualities and characteristics is obtained. Products made from such alloys are not exposed to environmental influences and have high wear resistance.

Application of alloys

Without zinc and its alloys, many industries from mechanical engineering to medicine cannot exist.

Application of zinc alloys in various fields and industries:

• mechanical engineering - for the production of gas tanks, trunk lids, carburetor bodies, mufflers, gas pumps, radiators, pumps, accessories;
• foundry - weapon bolts;
• electrical engineering – production of accumulators and batteries;
• printing – for typing texts and printing illustrations;
• processing of metal structures - metallization and galvanizing of various surfaces from destruction and corrosion of metal;
• medicine – antiseptic and anti-inflammatory drugs, obtaining radionuclides for the diagnosis and treatment of a number of diseases;
• paint production – production of zinc white;
• construction – for roofing, wall cladding, drainpipes, gutters;
• art – coinage, graphics;
• jewelry - personal jewelry, boxes, buttons, zippers, decorative overlays;
• household – for kitchen equipment, cornices.

Zinc casting alloys

The following requirements apply to alloys for injection molding. They have to:

• have excellent fluidity;
• do not react or weld to the mold;
• have a short crystallization interval;
• have strength at high temperatures.

Such alloys are used in the following cases:

1. For injection molding of parts with complex configurations and thin walls. This is how brake equipment parts and pumps are produced using the properties of alloys, such as resistance to cracking, fluidity, and low melting point.
2. For the production of cast decorative products. After galvanization, a beautiful and durable coating is installed on the surface. It may not be of very high quality if the surface is porous or contains excessive aluminum.
3. For the production of antifriction zinc alloys used in mechanical engineering.
4. For casting typographic fonts. With changes in technology, the need to manufacture them disappears.

Automotive industry

The automotive industry is one of the leading areas of mechanical engineering. Research is steadily being carried out here on the use of the latest materials and alloys, which have significant performance and technological properties. These include zinc alloys in accordance with GOST 21437-75.

It includes four grades of alloys, two of which are casting, and the others are pressure-processable. These materials are used to produce car parts (bushings and bearings) with anti-friction properties.

Cast zinc alloys GOST 19424-74 and 25140-82 are used for the manufacture of carburetors with complex shapes and gasoline pumps by injection molding, using their high fluidity properties.

The disadvantage of alloys is that the parts are practically irreparable.

Instead of a conclusion

Brasses - zinc alloys - are widely used in the engineering industry. They are used to produce highly durable parts where precision castings are required.

Most of the world's zinc is used to make galvanized steel because it forms a protective film, preventing them from corrosion. Alloys are indispensable in the manufacture of various sources of electric current.

As a component in solders, this non-ferrous metal reduces the melting point. Medicines containing zinc oxide have anti-inflammatory and antiseptic properties.

An insufficient amount of zinc microelement in the human body leads to serious diseases: stomach ulcers, liver cirrhosis, atherosclerosis.

Source: https://www.syl.ru/article/371035/tsinkovyie-splavyi-gost-temperatura-plavleniya-svoystva-primenenie

Zinc alloy: special properties and main varieties

Thanks to archaeological excavations, it was discovered that zinc products began to be used around the 7th century AD. This metal was very common due to a number of useful properties. Zinc alloy can be made from various substances, which determine its characteristics. This material is used in various industries, including jewelry.

Properties and characteristics of zinc and zinc alloys

The characteristics of zinc alloys are largely determined by the properties of zinc. This metal is bluish in color, is not found in its pure form, and usually contains impurities that change its properties. Pure metal is obtained as a result of several reactions.

Zinc has the following chemical properties:

• When heated, it reacts with hydrogen sulfide and water to release hydrogen.
• Does not react with nitrogen and carbon.
• It reacts with alkalis to form zinc acid salts - zincates.

Zinc is a very durable material. Its ductility increases when heated. If it is heated by more than 210 degrees, this may change its shape. At low temperatures the substance melts.

https://www.youtube.com/watch?v=o74G0zUgqTY

What does zinc alloy look like?

The amount of impurities depends on the methods of metal extraction, the characteristics of its processing and the zinc grade. Most often you can find impurities in the form of nickel, chlorine, fluorine and lead. Usually, when creating zinc alloys, pure zinc is used, since the presence of impurities degrades the quality of the material:

• tin makes the alloy too brittle and brittle;
• in the presence of cadmium, the ductility of the material decreases;
• lead increases intercrystalline corrosion of the material and promotes its dissolution in acids;
• the presence of iron increases the hardness of alloys, but reduces their ductility;
• Arsenic causes the alloy to become brittle and non-ductile.

Therefore, to improve the characteristics of zinc alloys, zinc is first purified from impurities. And then they use pure metal, which is alloyed with various components.

Advantages and disadvantages

Most zinc alloys have the following advantages:

• they are very durable and are not damaged by mechanical stress;
• resistant to corrosion;
• have good casting qualities and can be used to create even small elements;
• Over time, they practically do not age.

However, even small amounts of impurities worsen the characteristics of the alloy. They lead to a decrease in melting point, swelling, and contribute to the appearance of cracks. Therefore, zinc alloys must be created in compliance with all technologies, and the amount of impurities in them should not exceed 0.005%.

Many people ask whether zinc alloys darken or not? This is another drawback of the material. Zinc alloys may darken over time. Moreover, the darkening usually spreads over the entire surface of the material. This is caused by the formation of an oxide film on the surface of the material. It forms at room temperature after contact with air or water. Therefore, to avoid this, electroplating is required.

Types of zinc alloys

Zinc can be alloyed with various substances, which will determine the properties of the resulting material. Alloying pure zinc with copper, aluminum and tin can improve its performance. The resulting composition will be of higher quality than the pure substance.

Scope of application

Zinc alloys are widely used. They are used in the following industries:

• In the automotive industry. Door handles, mirrors, and parts for car interior decoration are made from zinc alloys.
• When creating jewelry. Zinc is alloyed with gold, thereby increasing its ductility and malleability. This makes it easy to connect small parts to each other.
• In medicine. Zinc alloys are used to make medical furniture and devices. And zinc oxide is a good antiseptic, so it is added to various ointments and medicines.

Zinc alloy is used in automobile manufacturing

Thus, zinc and its compounds are used in many fields. But the substance is most widely used in the automotive industry.

Types of zinc alloys by purpose

According to their intended purpose, zinc alloys can be of several types:

• Deformable. 15% - aluminum, 5% - copper, more than 1% - magnesium. It is made in the form of sheets or rods. The properties are similar to brass.
• Foundries. They are made by adding 3-4% copper and aluminum to zinc, as well as 0.05% magnesium. They have good fluidity. Therefore, they are manufactured through injection molding or mold casting.
• Anti-friction. They contain 10% aluminum, 5% copper and 0.1% magnesium. Manufactured by injection molding. They have a low coefficient of friction and are used in the automotive industry.
• Solders. They are used for soldering aluminum parts. Usually include impurities - metals. This increases their strength.
• Typographic. They contain 7.5% aluminum, 2% magnesium and approximately 4% copper. Such alloys are very durable and cast well into molds.
• Protective. They contain no more than 1% aluminum and a tiny amount of silicon and magnesium. Resistant to corrosion even in damp environments. Therefore, such alloys are used as protective materials.

Zinc alloys have proven themselves well and are widely used. But when creating them, proportions must be accurately taken into account, otherwise poor quality material will be obtained.

Zinc alloy in jewelry

Externally, zinc alloys resemble noble metals. Therefore, they are used in costume jewelry to create inexpensive jewelry. Zinc alloy jewelry looks expensive but is easy to create.

Is zinc alloy harmful? In fact, it has no effect on the human body. But, nevertheless, it is better to purchase good quality jewelry. Usually, a special alloy is used to create jewelry, which is called costume jewelry. The most commonly used is brass or an alloy with aluminum. Externally, such products resemble gold and silver.

Is zinc alloy harmful in jewelry? No, so you can safely buy products made from it. After all, if it had a negative impact, making jewelry from it would be prohibited.

Thus, zinc and zinc alloys are widely available. They are used in medicine, automotive industry and even in jewelry. These are high-quality and sustainable materials that practically do not change under the influence of environmental conditions.

Source: https://1nerudnyi.ru/tsinkovyj-splav-01/

Zinc alloy

Judging by archaeological finds made in India, China and Greece, humanity has been using zinc to produce various products since about the 7th century. Tools, jewelry and even weapons were made using zinc alloys, but people learned to separate zinc from impurities only 300 years ago. The metal ore contains less than 5% zinc.

Dangerous zinc impurities

It is necessary to separate zinc from impurities not only because of their effect on the working qualities of the metal, but also because many of them are harmful to humans.

Most often, zinc-containing ores contain impurities of the following metals:

• tin,
• cadmium,
• lead,
• iron,
• copper,
• arsenic,
• antimony.

The presence of most of these impurities makes zinc castings more durable, but negatively affects their ductility, resistance to corrosion and makes them more brittle and brittle.

• The presence of tin makes the alloy too brittle;
• The presence of cadmium reduces ductility;
• Lead promotes dissolution in acids;
• Iron inclusions make the alloy harder, but make the alloy less strong and complicate the melting process;
• The presence of copper also makes the alloy harder, but on the contrary improves the quality of casting, although it reduces ductility and resistance to corrosion;
• The presence of arsenic makes the alloy more brittle and less ductile;
• When a zinc alloy with an admixture of antimony is heated, the edges of the casting crack and the ductility decreases.

Types of zinc alloys and their properties

Alloys with various metals: copper, magnesium, aluminum, nickel are easily soldered and welded, have a lower melting point and are better poured into molds. Each of these metals affects the properties of the alloy in its own way and is used in different industries.

According to their purpose, zinc alloys are divided into the following types:

1. Deformable. Approximately 15% aluminum, 5% copper and less than 1% magnesium, similar in properties to brass, manufactured using fill or semi-continuous casting and subsequent production of sheet or rod material;
2. Foundries. They are obtained by adding no more than 3.5-4% copper and aluminum and a small amount (approximately 0.05%) magnesium to the metal, they are characterized by good fluidity and do not interact with the material of the casting mold, they are manufactured using injection molding or casting into molds;
3. Anti-friction. They contain more than 10% aluminum, about 5% copper and less than 0.1% magnesium, they are widely used in the manufacture of bearings, due to the low coefficient of friction, they are manufactured using injection molding;
4. Solders. Used for soldering aluminum. Depending on the brand, they may include aluminum, copper, cadmium, silver, lead and other metals, which are characterized by high strength and ductility, but are susceptible to corrosion;
5. Typographical. They contain up to 7.5% aluminum, slightly less than 2% magnesium and up to 4.5% copper, are durable and pour well into molds, and are used for casting typographic fonts;
6. Protective. They contain less than 1% aluminum and small amounts of magnesium or silicon, resist corrosion well in humid environments, and are used as protective metals in many industries.

Among the common and well-known zinc alloys are:

1. Brass. Zinc-copper alloy. Copper is the main component. Depending on the copper content, green, yellow and golden brass are distinguished. At temperatures above 300°C, brass may become deformed. There are also multi-component brasses; they are obtained by adding a number of other metals to the alloy.
2. TsAM. An alloy of zinc, aluminum and copper with a small amount of magnesium. They have a low melting point, cast well and make stronger products. The group of copper-zinc alloys with the addition of magnesium and aluminum used in industry is designated by the abbreviation TsAM. They melt at a relatively low temperature, and therefore pour well into molds. Products made from TsAM group alloys are much stronger.
3. Virenium is an alloy of copper and zinc with a small addition of nickel.

The influence of various metals on the properties of the alloy

Copper-zinc alloys are increasingly used in the manufacture of various industrial products, and the presence of metals such as magnesium, aluminum, and nickel improves their performance.

They are easier to process by soldering and welding, have a lower melting point and are better poured into molds. Each of these metals affects its properties in its own way and is used in different industries.

Is zinc alloy in jewelry harmful?

In their appearance, such jewelry resembles precious metals, so they are widely used in the jewelry industry. They are often used to make jewelry. Jewelry made from zinc alloys looks quite expensive, but due to its ease of processing, it is easy to manufacture.

There is a special zinc alloy that is used only for making jewelry; it is called “costume jewelry”; in the passport for jewelry there is even a mark “zinc alloy for costume jewelry.”

Brass or tombak (golden brass) is most often used in the production of costume jewelry; it is less susceptible to corrosion, therefore it is used in the production of more expensive jewelry. Jewelry made from an alloy of copper and zinc with the addition of aluminum looks very similar to silver.

For the manufacture of jewelry, zinc is used, purified from nickel, lead and other metals hazardous to humans. The passport for such jewelry must include a note indicating the absence of harmful impurities in the alloy from which it is made. Therefore, we can talk about the absolute safety of such jewelry for the people wearing them.

Does zinc alloy rust or not?

To prevent rust, jewelry containing zinc is treated with a special protective compound, and such jewelry can last quite a long time.

Is it getting dark or not?

True, zinc, interacting with atmospheric oxygen and various household liquids, including water, is susceptible to oxidation even at normal temperatures, which contributes to the darkening of zinc alloy products. Such jewelry can leave marks on clothing and skin, so they require additional care.

Also, to prevent oxidation, some manufacturers electroplate zinc products with gold or silver, but such treatment significantly increases the cost of jewelry.

Zinc deposits are quite common on earth, and despite its low content in ore and the difficulty of purifying it from impurities, the zinc obtained from it and its alloys with other metals are increasingly used in various industries.

Source: https://prompriem.ru/splavyi/cinkovyj.html

Zinc

 Zinc is a brittle, bluish-white transition metal (tarnishes in air, becoming coated with a thin layer of zinc oxide).
  Essential (irreplaceable) microelement of human tissues. In terms of quantitative ratio in the body, it ranks second, after iron, in place. It plays a key role in the regeneration of damaged tissues, since without zinc the synthesis of nucleic acids and proteins is disrupted.

STRUCTURE

Zinc crystals have a hexagonal packing of atoms. But unlike the dense hexagonal packing of spherical atoms, zinc lattices are elongated in one direction. Each atom is surrounded by six other atoms lying in the same plane or layer. The distance between the centers of neighboring atoms in this flat layer is equal to 0.26649 nm. The external electronic configuration of the atom is 3d104s2. Not polymorphic.

PROPERTIES

At room temperature it is fragile; when the plate is bent, a cracking sound is heard from the friction of the crystallites (usually stronger than the “cry of tin”). Has a low melting point. The volume of metal during melting increases in accordance with the decrease in density.

With increasing temperature, the kinetic viscosity and electrical conductivity of zinc decrease and its electrical resistivity increases. At 100-150 °C zinc is plastic. Impurities, even minor ones, dramatically increase the fragility of zinc. Is diamagnetic.

Reserves and production

The average zinc content in the earth's crust is 8.3·10-3%; in basic igneous rocks it is slightly higher (1.3·10-2%) than in acidic rocks (6·10-3%). Zinc is an energetic aquatic migrant; its migration in thermal waters along with lead is especially characteristic.

Zinc sulfides, which are of industrial importance, precipitate from these waters. Zinc also migrates vigorously in surface and underground waters; the main precipitant for it is hydrogen sulfide; sorption by clays and other processes play a lesser role.

Zinc deposits are known in Iran, Australia, Bolivia, and Kazakhstan. In Russia, the largest producer of lead-zinc concentrates is JSC MMC Dalpolimetal

Zinc is extracted from polymetallic ores containing 1-4% Zn in the form of sulfide, as well as Cu, Pb, Ag, Au, Cd, Bi. Ores are enriched by selective flotation, obtaining zinc concentrates (50-60% Zn) and at the same time lead, copper, and sometimes also pyrite concentrates.

The main method of obtaining zinc is electrolytic (hydrometallurgical). Calcined concentrates are treated with sulfuric acid; the resulting sulfate solution is cleaned of impurities (by precipitating them with zinc dust) and subjected to electrolysis in baths tightly lined inside with lead or vinyl plastic.

Zinc is deposited on aluminum cathodes, from which it is removed (stripped off) daily and melted in induction furnaces.

ORIGIN

Zinc does not occur in nature as a native metal. There are 66 known zinc minerals, in particular zincite, sphalerite, willemite, calamine, smithsonite, and franklinite. The most common mineral is sphalerite, or zinc blende. The main component of the mineral is zinc sulfide ZnS, and various impurities give this substance all kinds of colors.

Due to the difficulty of identifying this mineral, it is called blende (ancient Greek σφαλερός - deceptive). Zinc blende is considered the primary mineral from which other minerals of element No. 30 were formed: smithsonite ZnCO3, zincite ZnO, calamine 2ZnO · SiO2 · H2O. In Altai you can often find striped “chipmunk” ore - a mixture of zinc blende and brown spar.

From a distance, a piece of such ore really looks like a hidden striped animal.

APPLICATION

Pure zinc metal is used to recover precious metals mined by underground leaching (gold, silver). In addition, zinc is used to extract silver, gold (and other metals) from crude lead in the form of zinc-silver-gold intermetallic compounds (so-called “silver foam”), which are then processed by conventional refining methods.

It is used to protect steel from corrosion (galvanization of surfaces not subject to mechanical stress, or metallization - for bridges, tanks, metal structures).

Zinc is used as a material for the negative electrode in chemical power sources, that is, in batteries and accumulators.

Zinc plates are widely used in printing, in particular, for printing illustrations in large-circulation publications. For this purpose, zincography has been used since the 19th century - making cliches on a zinc plate by etching the design in it with acid. Impurities, with the exception of a small amount of lead, impair the etching process. Before etching, the zinc plate is annealed and rolled in a heated state.

Zinc is added to many hard solders to reduce their melting point.

Zinc oxide is widely used in medicine as an antiseptic and anti-inflammatory agent. Zinc oxide is also used to produce paint - zinc white.

Zinc is an important component of brass. Zinc alloys with aluminum and magnesium (ZAM, ZAMAK), due to their relatively high mechanical and very high casting qualities, are very widely used in mechanical engineering for precision casting.

In particular, in the arms industry, pistol bolts are sometimes cast from the ZAMAK (-3, −5) alloy, especially those designed for the use of weak or traumatic cartridges.

Also, all kinds of technical accessories are cast from zinc alloys, such as car handles, carburetor bodies, scale models and all kinds of miniatures, as well as any other products that require precise casting with acceptable strength.

Zinc chloride is an important flux for metal soldering and a component in fiber production.

Zinc telluride, selenide, phosphide, and sulfide are widely used semiconductors. Zinc sulfide is an integral part of many phosphors. Zinc phosphide is used as a rodent poison.

Zinc selenide is used to make optical glasses with very low absorption coefficients in the mid-infrared region, such as in carbon dioxide lasers.

Zinc - Zn

Crystallographic properties

Source: http://mineralpro.ru/minerals/zinc/

Zinc alloys: description, structure and properties

Metals and alloys have become so integral to our lives that sometimes we don’t even think about them. Back in the 4-3 millennia BC, man first became acquainted with nuggets. A lot of time has passed since then, and every year metal processing has only improved.

A metal such as zinc played a big role in this. Alloys based on it are used in many industries. In this article we will look at zinc alloys and their role in our lives.

Transition metal

Zinc is known to be a bluish-white, brittle transition metal. It is mined from semi-metallic ores. The process of obtaining pure zinc is quite complex and labor-intensive. First of all, ore containing 1-4% zinc is enriched by selective flotation.

This process produces concentrates (55% Zn). Next, you need to obtain zinc oxide. To do this, the resulting concentrates are fired in fluidized bed furnaces. Only from zinc oxide can this metal be obtained in its pure form, and there are two ways to do this.

Obtaining zinc

The first is electrolytic, based on the treatment of zinc oxide with sulfuric acid. As a result of this reaction, a sulfate solution is formed, which is purified from impurities and subjected to electrolysis. Zinc is deposited on aluminum cathodes, which is then melted in induction furnaces. The purity of zinc obtained in this way is about 99.95%.

The second method, the oldest, is distillation. The concentrates are heated to a very high temperature (about 1000°C), zinc vapors are released, which settle on clay vessels by condensation. But this method does not give such purity as the first. The resulting vapor contains about 3% of various impurities, including such a valuable element as cadmium.

Therefore, Zn is further purified by segregation. It is left to stand at a temperature of 500°C for some time and a purity of 98% is obtained. This is enough for the further production of alloys, because then the zinc is still alloyed with the same elements. If this is not enough, rectification is used and zinc is obtained with a purity of 99.995%.

Thus, both methods make it possible to obtain high-purity zinc.

An inseparable pair of metals

As a rule, lead is present in zinc alloys as an impurity. In nature, this inseparable pair of metals is found quite often. But in fact, high lead content in a zinc alloy degrades its physical properties, creating a tendency to intergranular corrosion if its content exceeds 0.007%. Most often, lead and zinc are found together in tin bronzes and brass.

If we talk about the eutectic of these two elements, it is important to note that up to a temperature of 800°C they do not mix with each other and represent two different liquids. With rapid cooling, Pb is uniformly distributed in the form of rounded inclusions along the grain boundaries. Zinc-lead alloy is used to make printing clichés due to the fact that it dissolves very quickly in acid. Most often, lead impurities are removed from zinc using the distillation method.

Copper-zinc alloy

Brass is an alloy known even before our era. At that time, zinc had not yet been discovered, but the ore was used quite widely. Previously, brass was obtained by alloying smithsonite (zinc ore) and copper. It was only in the 18th century that this alloy was first made using the metal zinc.

Nowadays, there are several types of brass: single-phase and two-phase. The former contain about 35% zinc, and the latter – 50% and 4% lead. Single-phase brass is very ductile, while the second type is characterized by brittleness and hardness.

Having examined the phase diagram of these two elements, we can conclude that they form a series of electronic phases: β, γ, ε. An interesting variety of brass is tombak. It contains only up to 10% zinc and due to this it has very high ductility. Tompak is successfully used for cladding steel and producing bimetals.

Previously, it was used to make coins and imitate gold.

Zinc and steel

In almost every home you can find galvanized things: buckets, pots, boiling pots, etc. All of them are reliably protected from rust thanks to zinc.

Figuratively speaking, of course, this metal is sprayed onto the steel, and logically we are not talking about an alloy. On the other hand, knowing how galvanizing occurs, one can say the opposite.

The fact is that zinc melts at a very low temperature (about 400°C), and when it hits the surface of steel in a liquid state, it diffuses into it.

The atoms of both substances bind very tightly to each other, forming an iron-zinc alloy. For this reason, we can safely say that Zn is not “laid” on the product, but “embedded” in it. This can be observed in ordinary everyday situations. For example, a scratch appears on a galvanized bucket. Is it starting to rust at this point? The answer is clear - no.

This happens because when moisture gets in, the zinc compounds begin to deteriorate, but at the same time they form some kind of protection for the steel. So, in most cases, such zinc alloys are intended to protect products from corrosion.

Of course, other substances, such as chromium or nickel, can be used for these purposes, but the cost of these products will be many times higher.

Areas of application of zinc and its alloys

In fact, parts made of zinc alloys are quite common in our time. Despite the fact that plastic is replacing metal products, in some cases it is impossible to do without them. For example, the automotive industry is an industry that cannot do without zinc alloys. Filters, sedimentation tanks, carburetor and fuel pump housings, wheel covers, mufflers - all this and much more is made using compounds of this chemical element.

Due to the fact that zinc alloys have good casting properties, complex parts of various shapes with minimal wall thickness are cast from them. Construction is another area where these alloys cannot be avoided.

Rolled zinc is used for roofing, pipes and gutters.

Despite the fact that there is a tendency to reduce the production of zinc alloys, it is not possible to abandon their production due to the relative cheapness and mechanical properties of the material.

Source: https://FB.ru/article/342309/tsinkovyie-splavyi-opisanie-struktura-i-svoystva