How is brass made - Metals and their processing

How to weld brass, what technologies exist

Brass is not a pure chemical element, it is an alloy consisting of zinc and copper. There are no standards for the quantitative content of metals in an alloy, so their percentage varies from 20% to 30% for each element.

Often, some other elements can be found in brass. A multicomponent composition implies the presence of tin, lead, nickel, manganese or iron. Many people equate the concepts of brass and bronze.

From a metallurgical point of view, these are two different alloys, which have differences in both physical and chemical properties.

Industrially, all brass alloys are divided into two types:

Single-phase alloy - an alloy in which zinc is present in an amount not exceeding 35%. It is also called “alpha” alloy. In terms of physical properties, alpha is characterized by plasticity. Products can be deformed without preheating them.
The two-phase alloy contains much more zinc. Its share can reach 60%. This alloy is called "alpha-beta" and has a strong structure. Products made from two-phase brass are distinguished by their durability. To change the shape, it is necessary to increase the temperature of the product or increase the external pressure.

Peculiarities
Preparation
Arc welding
Argon
Gas

Peculiarities

Brass can be welded, but this process is considered technologically complex. The components included in its composition in the form of zinc and copper differ in physical and chemical properties, therefore, they behave differently under the same conditions. Despite this, welding is, in principle, possible. If you learn all the features of the behavior of metals, you can carry out welding using trivial methods, and at home. In its technology, the process is similar to copper welding.

There are several traditional obstacles that every welder faces when carrying out the welding process. The main problem is the large gap between the melting temperatures of the metals that make up the brass alloy.

If the melting point for copper is 1080°C degrees, then zinc melts at 420°C, and at 905°C degrees zinc begins to boil (at normal pressure).

As a result of the action of the electric arc, the zinc melts and boils. From the place where the seam is formed, it gradually evaporates and burns out.

Zinc reacts with oxygen during the welding process. The resulting oxide in the form of a film covers the part. It forms precisely in the seam zone, but it is this film that prevents normal fusion. In addition, pores and cracks quickly begin to appear in brass when heated. They are due to the fact that as the temperature rises, the process of hydrogen absorption begins. It forms bubbles in molten metal. As a result, the porous structure of the seam negatively affects its strength.

To summarize the presented theory, we can identify three main problems characteristic of welding brass:

evaporation and burnout of metal (zinc);
formation of pores and cracks;
formation of zinc oxide (white film).

Preparation

The thermal conductivity of the copper-zinc alloy is much lower than that of the constituent elements, so there is no need to preheat the workpieces for welding. If the thickness of the material is impressive, then you can limit yourself to local heating.

The joints of the workpieces are processed in several ways, based on the thickness of the metal sheet. With a thickness of up to 1.5 mm, a flange is made along the edge. The height of the side should reach twice the thickness of the sheet. When the workpiece thickness is from 1.5 mm to 6 mm, the surfaces are not processed, and when welding, a gap of 1-2 mm is provided between the edges. The use of shims requires increasing the gap to 3 mm. Edges of greater thickness are cut at an angle of 30-45°C degrees.

In order to carry out high-quality welding of any alloy, it is necessary to take into account the properties of each component element. Welding brass is similar to welding copper, but the presence of zinc makes some adjustments to the algorithm. It is customary to distinguish three methods of welding brass:

arc welding;
argon arc welding;
gas (gas-flame) welding.

Arc welding

Electric arc welding is carried out using inverter machines operating in MMA mode. For this purpose, special electrodes are used. The welding method depends on their type. A distinction is made between welding with brass or carbon electrodes.

Welding with brass electrodes is carried out with direct current of direct polarity. The operation is characterized by a short arc at a current of 250 A; this parameter is given for electrodes with a diameter of 5 mm. With such indicators, the suture application speed reaches 30 cm per minute.

After applying the seam, it is subjected to forging and heating to 600°C degrees.

Welding with carbon electrodes involves the use of graphite consumables (thickly coated electrodes). They consist of brass wire, which contains elements such as manganese, iron, aluminum and silicon. To produce the coating, mixtures of liquid glass with dry impurities are used. The most popular include manganese ore, ferromanganese, chalk chips, aluminum and graphite.

When using carbon electrodes, an additive coated with special fluxes is used. Such welding is carried out with the above parameters, however, they are already suitable for electrodes with a cross section of 10 mm. There are a number of mandatory conditions necessary to obtain a strong seam when conducting electric arc welding:

Workpieces with a thickness of 6 mm or more should be locally heated before applying a seam.
Thin sheets are welded in one pass. When several layers are applied to the workpiece, cracks will begin to appear in the seam area.
The thickness limit for one pass is 3 mm.
An asbestos lining is placed below or on the inside of the seam. It is needed to prevent metal leakage.

Argon

Argon or argon arc welding is a type of arc welding that has certain features. Welding is carried out with a non-consumable tungsten electrode in a protective gas environment, the role of which is argon. If TIG inverters were as common as MMA inverters, brass TIG welding would be the most popular joining method. Moreover, this particular welding method ensures high quality.

They resort to the argon-arc method when welding fairly massive workpieces. First, the surfaces are prepared. It comes down to cleaning the edges to a characteristic shine. Brass oxidizes quickly, so you often have to deal with the oxide layer. To do this, the edges are treated with nitric acid, after which the workpiece should be washed and dried.

When welding, you need to get a long arc. A continuous seam is excluded, since in the process of its application the metal may burn through. The seam is formed from individual rollers.

Welding brass is characterized by a gradual decrease in voltage. When using a tungsten non-consumable electrode, an additive is used. The best option for the additive material is bronze or phosphorus.

A special rod is made from these elements, which is inserted at one end into the seam formation area. But when carrying out argon welding, the use of consumable electrodes is also allowed.

One way or another, the process is accompanied by a characteristic cracking sound that occurs when zinc evaporates.

The advantages of argon-arc welding can be formulated in more detail.

This method is considered the least expensive. The purchase of carbon or brass electrodes, which also require flux, will require considerable funds.
High quality indicators combined with relative safety place this method in the category of advanced ones.
High speed of seam formation.
The appearance of the seam is aesthetic. Do not forget that many brass products are decorative elements, so a neat seam is the key to high-quality work by a craftsman.
The gases released, including zinc compounds, are considered toxic. During the welding process, they are blown out with argon and cannot cause much harm to the welder.
There is no slag crust that would subsequently have to be knocked down or cleaned off.
Argon prevents rapid oxidation on machined edges.

Gas

Gas welding of brass is used in exceptional cases. Basically, it is carried out in the absence of electricity or when it is impossible to conduct electric arc welding. The formed seam is quite strong and of high quality, but this method is accompanied by intense evaporation of zinc. This process can only be hindered by an oxidizing flame. As a result of the reaction of the compound with oxygen, a film is formed on the surface, which prevents the gas from escaping.

In gas welding, combustible gas is burned in a special burner. Its role is played by acetylene, hydrogen, natural gas, gasoline or kerosene vapor. The most popular is a mixture of acetylene and oxygen, as it has a high calorific value.

The power of the flame directly affects the quality of the seam, so before performing work it is necessary to adjust the welding parameters. Gas welding technology involves heating the filler material in a flame.

The rod with the additive should always be in a high temperature zone, and the seam itself should be applied at maximum speed.

The wire, which plays the role of filler material, does not require the use of additional flux. Silicon brass wire is usually used and produces a tight and durable weld. Excess waste must be washed off with water. The seam is then forged, annealed and slowly cooled. When working on a vertical surface, you should remember the fluidity of the metal.

Source: https://svarkoy.ru/teoriya/svarka-latuni.html

Production technologies, composition and structure of brass alloy

Metals and alloys are literally the basis of human civilization. Pure metals are not very often used in the national economy, but alloys are used everywhere. This is not surprising, since the alloy combines the properties of several substances in the best proportion. This article talks about the production and processing of molten brass, preparation of the material, composition, properties and application of the material.

Structure and chemistry The composition of brass is a very important issue. Brass is a two- or multicomponent solid solution – an alloy based on copper and zinc. Brass has been known for an extremely long time, dating back to the time of Ancient Rome, and is still used today. Its properties depend on its quantitative composition.

The traditional composition of brass is 70% copper and 30% zinc. Zinc improves the mechanical and technological qualities of the alloy, and at the same time reduces its cost, since it is a more affordable metal. In practice, the use of solutions with a zinc content of more than 50% is rare.

Brass has a very beautiful golden color. However, without a protective layer - varnish, for example, it darkens quite quickly. In quite a large number of cases this property is not considered a disadvantage.

The alloy is marked depending on its composition. Brass is designated by the letter “L”, followed by a number indicating the proportion of copper – 70, for example. If the alloy has been alloyed, then all additives are indicated by decreasing their proportion, and then the composition is indicated. For example, LAZH60-1-1 means that brass contains 60% copper, and that the alloy is alloyed with aluminum - 1%, and iron - 1%.

This video will tell you how brass burns and how the material is melted at home:

Compositions are classified according to the proportion of zinc:

if its content is 5–20%, brass is called red - tompak;
if the proportion of zinc ranges from 20–36%, the alloy is called yellow brass;
an alloy with a zinc share of 48–50% is called technical.

In the production of brass, more than 50% of zinc is obtained from the processing of recycled materials, so the alloy can be classified as a fairly environmentally friendly product.

Separation by quality of additional ingredients

Alloys are divided according to the quantity and quality of additional ingredients.

Two-component

Two-component ones include only copper and zinc. Here the properties of the alloy are strongly influenced by the phase composition. Copper can dissolve no more than 39% of zinc. Moreover, as the temperature increases, the solubility decreases, and only a single-phase solution is formed - the α-phase. Such alloys are called α-brasses; they are characterized by high ductility and are quite strong if the proportion of zinc reaches 30%.

As the proportion of zinc increases, part of the metal no longer dissolves and a two-phase solution is formed - α + β'-brass. The β' phase is harder, but also more brittle, so this alloy is stronger, but loses its ductility.

This feature also determines the unusual processing method. So, for cold processing - shaped profiles, wire, only α-brass is used, since its ductility is high at low temperatures, and in the temperature range from +300 to 00 C drops sharply, so it is useless to deform brass when heated. But α+β'-solutions are processed precisely at high temperatures.

Multicomponent

Multicomponent additives may contain:

nickel – increases corrosion resistance;
silicon - reduces strength, but together with lead gives anti-friction properties;
lead – no more than 4%, reduces strength, but facilitates machining. Such brass is often called automatic;
iron – reduces grain growth, which improves the mechanical properties of the alloy;
tin is no more than a fraction of zinc. Otherwise, the alloy turns into one of the varieties of bronze. Tin gives the alloy resistance to sea water, which is why this type of brass is called sea brass;
manganese – increases corrosion resistance and promotes strength.

Next, we will look at technologies and equipment for brass casting, molds, temperatures and other important nuances of brass production in Russia.

Metal production

Since the main component of brass is copper, the material is classified as a copper alloy. The production scheme is quite simple. However, from a technological point of view, the process turns out to be complex, since it requires very strict adherence to temperature conditions and processing of raw materials and workpieces.

In general, the production of the alloy looks like this:

melting copper in special crucibles;
introduction of zinc;
introduction of additional components - iron, nickel;
pouring into molds;
hardening - by stamping or drawing.

The matter is further complicated by the fact that the conditions for obtaining alloys largely depend on the composition of the alloy and its purpose.

Below is a video about melting brass at home.

The video below explains how to produce and melt brass at home:

The production of brass should begin with the extraction of copper from copper ore. In fact, this is a complex polymetallic raw material, in which the proportion of copper is small. The main components are waste ore, iron and copper, and the first step in obtaining brass is to separate the copper from the other components.

Receiving raw materials

The process is extremely complex, since its goal is to transfer raw materials from a single multicomponent mixture into a heterogeneous system consisting of several phases with different compositions and different properties.

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Only after this the phases can be separated from each other and compositions suitable for further use can be obtained.

A variety of methods are used for this: in some cases, the extracted phase is additionally enriched with the “main” metal, in others, on the contrary, it is depleted, in others they resort to mechanical separation methods when the phases, for example, differ in solubility, and so on.

The following two methods are most often used.

Pyrometallurgical technology involves processing copper ore with subsequent refining of blister copper. It includes smelting, converting copper matte, fire refining - essentially removing large impurities, and electrolytic refining. The latter allows not only deep purification of copper, but also the extraction of any associated components if they are of value.
The hydrometallurgical method is used when using low-grade copper ore. Its essence comes down to leaching - the effect of sulfuric acid, iron sulfate. To do this, the ore is crushed and dissolved in solvents, and then the copper is extracted either by cementation - the deposition of pure copper on iron, for which ordinary scraps of sheet and wire are used, or by electrolysis.

In this way, it is possible to completely extract copper from even the poorest ore.

Obtaining zinc also has its own characteristics, but, in general, is a simpler process.

We will tell you below whether it is possible to weld brass at home and how it is produced at a factory.

Alloy production method

Smelting of brass depends on the composition of the alloy. Here it is necessary to take into account both the different boiling temperatures of metals and different oxidation abilities.

Melting with pure metal - when using recycled metals, the charge can be loaded in any order. If there is pure metal in the charge, then copper is melted first, and then the circulating metals. Zinc and lead, if any, are introduced into the melt last, pre-heated to 100–120 C. Melting is carried out under a layer of charcoal, which is loaded with the first portion of the charge.
Melting silicon brass - this composition tends to absorb reducing gases, so charcoal is not used here. Melting is carried out under a covering flux - glass or borax - to prevent interaction with oxygen. Copper is loaded into the furnace first, then waste and copper-silicon master alloy. Zinc is loaded into the melt last, after the slag has been removed.
Melting of manganese brass is carried out under charcoal or glass flux. In this case, manganese is introduced last along with alloys, after all other ingredients are melted.

Sheet production

The usual form of brass production is sheets and wire. In general, the process goes like this.

Ingots from the melting shop go to the rolling shop, where they are heated in a furnace to a deformation temperature of –790–830 C.
At the mill, the ingots are deformed to the size and thickness of the workpiece.
The workpiece in the form of a roll is supplied for welding and then subjected to double-sided milling.
Then the semi-finished product is returned to the rolling shop, where it is rolled in a three-stand rolling mill until the specified sheet thickness is obtained.
The finished strip is cut into measured lengths.
The sheets are annealed in chamber furnaces and then pickled in pickling baths.
The material is deformed again to its final thickness and etched again.

Read below about the equipment for casting brass at the brass manufacturing plant.

Since copper is a metal in demand, production uses methods for extracting copper from both rich and very poor ores. So the raw material can be almost any ore that contains at least some amount of metal.

Producing brass is a multi-stage and technologically complex process. So the equipment here includes both the latest technological lines and the most traditional foundry tools.

For melting brass, the best option is an induction channel furnace or an electric resistance crucible. This equipment consumes a minimum amount of electricity based on the production of 1 kg of alloy and allows for minimal overheating of metals. The worst choice is electric arc furnaces.
To heat the ingots before deformation, a methodical furnace is used - here heating from 650 to 1200 C is possible.
Hot rolling mill – the working module is the working stand in which hot rolling is carried out. The equipment can also be used for cold rolling of sheets and strips.
Welding line - equipment depends on the parameters of the workpieces and finished products.
Milling machine – for double-sided milling of welded strip.
A cold rolling mill is usually a three-stand mill. To service it, you also need a hoist - it feeds rolls into the mill, a storage roller table - with its help, a batch of strips of the same brand is assembled, and an input section - an unwinder, a folder, a straightening machine, and so on.

In addition, the line must include equipment - from a cart to a loading crane, which ensures the movement of ingots, blanks, rolls and sheets between technological units.

At the stage of obtaining alloys, you will also need mechanical tools:

bell - a device for cleaning and degassing alloys, perfect for introducing refining fluxes;
slag – a tool for removing slag from the surface of the alloy;
pouring spoon;
two-handed ladle – a device for casting non-ferrous alloys.

The production of brass, or rather, the sheets and wire necessary for the manufacture of finished products, is a technologically complex and labor-intensive process. It is possible to obtain an alloy that meets GOST requirements only at large non-ferrous metallurgy enterprises.

The video below shows brass being cast into a mold:

Source: http://stroyres.net/metallicheskie/vidyi/tsvetnyie/latun/proizvodstvo-tehnologiya.html

Brass: history, main components, properties and applications

Brass is a copper-zinc alloy in which its constituent elements are found in certain proportions. In some cases, to impart certain properties, other alloying components (tin, nickel, lead, iron, etc.) are also included in the composition. It is worth noting that the scope of its application is almost limitless.

Excursion into history

Brass was known to mankind even before our era, and this despite the fact that zinc as an element became known only in the 16th century. For example, in the Ancient Roman Empire, molten copper was mixed with zinc ore (galma). The resulting metal was used to make beautiful jewelry and elegant dishes. It was also known in Central Asia, and it was from there that it came to Rus'.

Main components

Initially, in the classic version, brass was made by mixing copper and zinc in a 1:1 ratio. Now, basically, the specific gravity of zinc in an alloy does not exceed the thirty percent threshold (the exception is technically alloys, in which the volume of zinc can reach up to fifty percent).

According to its composition, such non-ferrous metal is divided into two types:

Two-component. The composition includes only two components - copper and zinc, their proportion depends on the purpose of the alloy. The alloy is designated by the letter “L” and a number. The number indicates the percentage of copper in the metal.
Multicomponent. It is made by adding alloying metals (tin, aluminum, lead, etc.). The marking is made with two letters (“L” (brass) and the letter of the additional component), followed by numbers indicating the percentage of metals - copper, additional metal, zinc.

Based on zinc content, two types are determined:

Red - specific gravity of zinc is less than 20 percent.
Yellow - the amount of zinc exceeds the twenty percent threshold.

What properties does brass have?

The melting point of the compound varies from 880 to 950 degrees. The initial melting point depends on the percentage of copper zinc. The more of the latter, the correspondingly lower the melting point. In addition, it lends itself perfectly to both machining and forging. It also resists corrosion processes quite well. Due to its high degree of ductility at low temperatures, brass is a good structural material.

Along with positive qualities, it also has disadvantages:

Afraid of sea water.
Destroyed under the influence of carbon dioxide solutions and organic acids.
It darkens when exposed to air, so it requires additional varnish treatment.

Depending on the purpose of the brass alloy, it is divided into three types, which, in addition to common properties, also have their own:

Deformable metals (Tompak). In such a metal the amount of zinc does not exceed 10 percent. This alloy is distinguished by its ductility, high anti-corrosion properties and low friction force. Tompak is easily welded with iron.
Foundry brass. It received this name due to its low melting point, which allows it to be poured into special molds. zinc ranges from 50 to 80 percent. This unique alloy is not subject to surface changes due to friction and has high strength characteristics.
Automatic non-ferrous metal. Lead must be added to such a metal as an alloying component. The alloy tolerates machining well and the chips come off in small particles, which increases the processing speed and reduces wear on the cutters, which is very important for large volumes of work.

To impart special properties, alloying components are added to brass, each of which changes the structure of the composition and enhances its certain qualities:

Aluminum. An oxide film is created on the surface of the product, reducing the “volatility” of the alloy.
Magnesium. It is used in combination with aluminum and iron to impart increased strength characteristics and anti-corrosion properties.
Nickel. Prevents oxidative processes from developing.
Lead. Improves the malleability and ductility of the alloy, making it suitable for machining.
Silicon. Improves the strength of the alloy.
Tin. Thanks to tin, brass can be used in sea water.

Where is brass used?

Brass today is one of the most widely used non-ferrous metals created artificially. Depending on the quality characteristics, brass alloy is used in certain areas of industry. Thus, two-component brass with a zinc content of no more than 20 percent is used to create parts and assemblies of various machines and heat transfer devices. 40 percent zinc makes it possible to use it for stamping and the production of accessories.

Multi-component brass is used more widely. Pipes, parts of ships and aircraft are made from it; watches also cannot do without such an alloy.

Decorative and artistic compositions, insignia for law enforcement agencies are made from this brand of non-ferrous metal. Products that need to be cast in special molds (fittings, separators, plain bearings) are made from cast brass.

Automatic brass has proven itself well in the production of fastener parts (nuts, screws, bolts, etc.).

For a long time in Russia, brass has been used, and is still used today, for the manufacture of such an original Russian household item as a samovar. Sometimes even the most expensive products are made from relatively cheap brass. For example, the body of the world-famous Zipo lighter is made of brass.

Jewelers didn't ignore brass either. In practice, they distinguish three types of it - yellow (zinc varies between fifty to fifty), golden (a small amount of zinc), green (zinc in the alloy is more than 50 percent). When the alloy contains 15 percent zinc and 5 percent aluminum, the metal becomes similar to gold.

A good craftsman can make a piece of jewelry from such brass that is almost completely reminiscent of gold, and the average person is unlikely to notice the difference. This is something scammers often take advantage of, passing off fake jewelry as gold.

Very often, students in jewelry workshops train on brass alloys, honing their skills.

Thus, we can safely say that brass is a truly important element for human economic activity and, at least in the next century, the need for it will only grow.

Source: https://SoproMats.ru/materialyi/metallyi/latun/

How to solder brass: methods, review of materials, instructions

An alloy of copper and zinc, known since ancient times, is widely used in our time. Brass has high strength, is resistant to corrosion, and is ductile. Thanks to these properties, it is used to make parts of mechanisms and structural elements that are forced to constantly come into contact with aggressive environments.

Despite the reliability of the material, brass products sometimes develop various defects that require repair - breaks, holes, cracks. One way to restore elements is soldering. This process is not very complicated, but it has its own characteristics, so it is extremely important to know how to solder brass.

Familiarity with soldering technology will allow you to successfully carry out such work even at home.

What are the features of the technology?

This method of producing permanent joints is not as popular as welding. The reason is lower solder strength. Seams are formed by melting a filler material called solder. The most important difference between soldering is the melting temperature, which should be lower than that of the elements being connected. They do not change the state of aggregation, which makes it possible to reliably fasten dissimilar materials.

The low-temperature effect on the surface to be soldered has made soldering indispensable, and in some cases the only possible: for example, when it is necessary to obtain a permanent connection of dissimilar metals. The integrity of the processed parts is the main advantage of such a technological operation, since it allows you to work with the smallest elements without fear of their deformation or change in structure.

Soldering is especially relevant in electronics, where you have to work with miniature, very fragile microcircuits, and in electrical engineering, when there is a need to connect or extend conductors.

Classification of brass alloys

Brass can be double or multi-component. In the first case, the composition includes only copper and zinc, which increases the hardness of the alloy. Other components that improve its physical and chemical characteristics include aluminum, iron, silicon, manganese, nickel, tin, lead and other elements. For this reason, it is necessary to know exactly the composition of brass in advance; this will help determine the method, as well as the specifics of soldering.

Brass is classified according to its chemical composition:

Two-component (double, simple). It consists only of copper and zinc. The percentage of these components may vary. These compositions are marked with the letter “L” and a number, which always indicates the amount of copper. For example, L90 contains from 88 to 91% copper, zinc accounts for 8.8-12%. There are impurities, but their amount is minimal - about 0.2%.
Multicomponent (special). This brass has a large number of ingredients that increase the corrosion resistance of the alloy, its strength, and hardness. It is marked differently: another one is added to the letter “L”, meaning the alloying element, and another number appears - the percentage of alloying metal. For example, LA77-2 is aluminum brass, it contains 77% copper, about 2% aluminum, and the rest is zinc. All such alloys are named after the alloying element: ferrous, silicon, nickel, manganese, lead, etc.

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Brass is used to make various products. According to the degree of processing, these alloys are divided into:

deformable, they are used to produce bolts, nuts, car parts, brass strips, sheets, wire, pipes, pipes;
foundry (fittings, bushings, instrument parts, bearings, car hydraulic system fittings).

Based on the percentage of zinc, brass is divided into:

Red (tompak), containing 5-10% of this component. Such alloys are ideal for jewelry, figurines and similar artistic products.
Yellow, here the percentage of zinc is 21-36%.

The reason for the popularity of brass is its durability, reliability, resistance to temperature changes and mechanical stress. Therefore, parts made from this alloy are widely used in water supply systems, sewerage systems, and in mechanical and instrument making. Brass products have a long service life, but this is only true if their operating rules are not violated.

Efficiency and obstacles

There are several technologies that allow you to easily weld parts or products made of brass, but they are not simple, promise significant costs, and require certain work skills from the master. Soldering is an alternative that is technologically simpler, which means this option is also suitable for a home craftsman, since there is no need for a highly qualified performer.

If the zinc content in the alloy is not too high, then there are no insurmountable obstacles on the way to the goal: simple soldering using ordinary rosin can cope with the task. When the percentage of this metal in brass exceeds 15, special fluxes are required.

The reason is strong evaporation during soldering of copper and zinc; it leads to the formation of a strong oxide film on the material, and it is quite difficult to remove it. Therefore, without special solders and neutralizing fluxes, an ideal result cannot be achieved.

Selection of optimal materials

Before looking for the best option for soldering brass, you need to determine its brand. Only in this case can an acceptable result of the operation be guaranteed.

Choosing the right solder

This is the material, usually an alloy, that is used to solder the elements. its peculiarity is its melting point, which must be lower than that of the metals being joined. Typical examples of alloys are tin and lead, pure tin.

However, the quality, mechanical strength of such a clutch and appearance are very far from ideal. The reasons for poor quality are pores that appear as a result of zinc evaporation.

To ensure reliable contact, the melting temperature of the material must be significantly lower than brass, and the solder must have excellent adhesion to this alloy.

For soldering brass containing a large amount of copper, it is better to take compositions related to copper-zinc solders, since as a result of the addition of zinc, the melting point of these alloys is reduced. For example, PMC54 and PMC-48 solders melt at a temperature of 880°, PMC-36 - at 800-825°.
For the same alloys, you can use silver solders - grades from PSr12 to PSr72. If brass has a higher zinc content, then similar solders are recommended, but not lower than PSr40.
Relatively inexpensive copper-phosphorus solders are MF-1, MF-2, MF-3. They are plastic, but have good electrical conductivity. If the mechanical and vibration loads are high, then it is better to purchase solders with silver.
If it is necessary to guarantee special strength, then hard copper alloys are chosen: for example, the universal L-CuP6.

The latest brand of solder has a temperature range of 710-880. It is designed to work with bronze, red bronze, brass, as well as copper, when installing pipes, radiators, and heating systems. When using silver or phosphorus solders, it must be taken into account that brass dissolves rapidly, so the processing time (heating and soldering) must be reduced.

Fluxes: homemade or ready-made

Fluxes clean the surface of metals from grease and also prevent the formation of an oxide film. They are also selected depending on the composition of the alloys. For copper compounds, rosin alone is sufficient, but for brass a more aggressive agent is already needed. The simplest flux option for soldering brass is a mixture of borax and boric acid (1:1). It is poured with water (5 mm per 1 g), boiled, stirring, then cooled. However, the best characteristics are possessed by “professionals” - purchased compounds.

Borax flux. He has been known for a very long time, but since then he has not lost his fans. The reason for its popularity is its high-quality work.
Other brands are no less effective: PV-209 (from 700 to 900°), PV-209X (from 650 to 850°).

Source: https://dom-i-remont.info/posts/obshhie-voprosy/kak-payat-latun-kak-vyibrat-flyus-pripoy-i-podhodyashhiy-instrument/

Rules and methods for patination of brass

Many things and materials lose their attractiveness when they age, but this does not apply to metals and alloys made from them. Patina, or a coating of oxides, gives metal objects high cost and value.

It is for this reason that elements made of aged metal can be found in a stylized interior. Many people wonder how to patina brass at home.

In fact, this is not difficult to do, the main thing is to stock up on the necessary equipment and adhere to the rules for performing such work.

Patination: what is it?

In order to find out the essence of patination, you should learn about the characteristics of an alloy such as brass. The main part of its composition is copper, and the brass alloy is represented by zinc. Zinc can also be added to the alloy.

When interacting with air and certain chemicals present in the air, many metals and their alloys begin to become covered with oxides and oxides, which look like a brown-red or green coating. This coating is called patina; it is formed during the oxidation process of the metal.

The process of patina formation is called oxidation.

Patinated brass

Many people believe that patination is the same as oxidation. In fact, this is not true, because oxidation is a natural process, while metal patination is artificial aging. During the patination process, the metal or alloy changes its color and takes on an aged appearance.

How to age an alloy?

To apply patina to metal with your own hands, it is important to know not only how to age brass, but also how to work with the substances and tools used. First of all, you should take care to comply with personal safety rules.

The thing is that the patination agent and its analogues contain chemicals that can cause irreparable harm to human health. Therefore, during work, hands and eyes must be protected from accidental contact with the skin (mucous membranes) of aggressive substances.

It is necessary to organize work in a well-ventilated room.

Work on a metal object begins by preparing it for patination. First of all, the surface of the product should be degreased, and this can be done using acetone - just apply a small amount of this product to a cotton pad and thoroughly wipe the product with it. Then the brass product should be washed in running water and soap and dried.

A metal object can be patinated with a composition that is popularly called “sulfur liver”. It's easy to prepare:

Take 1 part of powdered sulfur and mix it with two parts of potash.
The resulting mass is placed in a glass container, which is then placed on low heat.
The powder should melt and sinter. As soon as this happens, you should count 15 minutes and only after they have expired, turn off the fire.
As soon as the mass is sintered, it should be crushed to the consistency of a powder. Store the powder in a jar with a lid.

Sulfur liver

There are several effective methods for aging brass using sulfur liver.

Take a liter of water and add 20 grams of powder to it. A brass object is dipped into the prepared solution and watch how the product changes color. After this treatment, the brass will turn a soft golden hue.
To make the alloy acquire a light gray tint, you need to take a liter of water and add 3 grams of liver sulfur and sodium chloride to it. The coloring of a brass product must be carefully monitored, and as soon as the desired effect is achieved, the object must be removed from the solution and rinsed with water.
Ammonia is gradually added to a concentrated solution of copper sulfate and wait until the solution acquires a bright blue hue. The cleaned object is immersed in such a solution for several minutes, after which it is taken out and heated a little. After this treatment, the product will acquire a brown tint. This method is also suitable for aging copper.
To age copper or brass, you will need sandpaper, which must be used to carefully treat the surface of the product. After sanding, you can apply a chloride patina solution to the product. You can also dip a product that needs patination into this solution.
To blacken brass, you can use a solution consisting of copper metal and nitric acid.
To obtain an olive-colored patina, you should prepare a solution consisting of Berthollet salt, ammonium chloride and copper nitrate. The solution should be heated and the brass product should be dipped into it for 15 minutes.
To obtain a golden-colored patina, you should treat a brass product with a solution consisting of 180 grams of milk sugar, 0.6 grams of copper sulfide and 180 grams of alkali. The solution is heated to 90 degrees, after which the brass product is dipped into it for 15 minutes.
To give brass a dark gray color, you need to use antimony. This substance should be applied to the surface of the product and rubbed with a stiff brush. Once the desired shade has been created, the product should be thoroughly washed and dried by placing it in sawdust.
You can also apply nitric acid to the surface of a brass product (to do this, use a cotton swab soaked in acid).

The recipes described for the products used to patina brass can also be applied to silver and pure copper.

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Source: https://DedPodaril.com/lityo/patinirovanie-latuni-v-domashnih-usloviyah.html

Brass

Brass is an alloy of copper and zinc (from 5 to 45%). Brass with a content of 5 to 20% zinc is called red (tompak), with a content of 20–36% Zn - yellow. In practice, brasses with a zinc concentration exceeding 45% are rarely used.

Zinc is a cheaper material compared to copper, so its introduction into the alloy, while simultaneously increasing the mechanical, technological and anti-friction properties, leads to a reduction in cost - brass is cheaper than copper.

The electrical and thermal conductivity of brass is lower than that of copper.

STRUCTURE

Copper and zinc form, in addition to the main α-solution, a number of phases of the electronic type β, γ, ε. Most often, the structure of brasses consists of α- or α+β'- phases: the α-phase is a solid solution of zinc in copper with an fcc crystal lattice of copper, and the β'-phase is an ordered solid solution based on the chemical compound CuZn with an electron concentration of 3/ 2 and a primitive unit cell.

At high temperatures, the β phase has a disordered arrangement ([bcc]) of atoms and a wide range of homogeneity. In this state, the β phase is plastic. At temperatures below 454–468 °C, the arrangement of copper and zinc atoms in this phase becomes ordered, and it is designated β'. The β' phase, in contrast to the β phase, is harder and more brittle; The γ phase is an electronic compound Cu5Zn8.

PROPERTIES

Density - 8300-8700 kg/m³. Specific heat capacity at 20 °C is 0.377 kJ kg−1 K−1. Electrical resistivity - (0.07-0.08)·10−6 Ohm·m. Diamagnetic, since copper and zinc are diamagnetic. 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 quite well (however, brass cannot be welded by fusion welding - you can, for example, by contact welding) and rolled.

Although the surface of brass, if not varnished, turns black in air, it resists the action of the atmosphere better as a mass than copper. It has a yellow color and is highly polished.

Bismuth and lead have a detrimental effect on brass, as they reduce the ability to deform when hot. However, lead alloying is used to produce free-flowing chips, which makes them easier to remove during cutting.

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

Brass: what it is, composition and properties of the alloy, areas of its application

Brass is a metal alloy based on copper (Cu) and zinc (Zn), to which nickel, lead, tin, aluminum, and manganese can be added. Depending on the composition, the alloy acquires different properties and colors.

Despite the discovery of zinc, which is the main component of brass, only in the 16th century, it was known to man before our era. For example, the Romans alloyed copper with galma (zinc ore) and made various jewelry and thin-walled utensils from the alloy.

The production of the alloy spread to Central Asia, from where the products reached Rus', where the strength and brilliance of the material were also appreciated. And only after the discovery of zinc in 1746, it became possible for the appearance of brass in the form familiar to modern people. This happened on July 13, 1781 , when James Emerson registered the corresponding patent, so they say that brass was discovered 2 times.

Brass composition

The classic formula for brass is the ratio of copper and zinc as 1:2. It is this ratio that was mentioned at the turn of the 19th and 20th centuries in the encyclopedic dictionary of Brockhaus and Efron.

In modern conditions, the amount of zinc added to copper can be significantly less, but, as a rule, does not exceed 30%, with the exception of technical alloys, in which the presence of 50% zinc is allowed.

The more zinc is added, the lower the cost of the final material, since zinc itself is cheaper than copper.

Based on the composition of the alloy, they are distinguished:

Two-component, the formula of which is quite simple and is a combination of copper and zinc in various proportions. Such an alloy, in accordance with GOST, is marked with the letter “L”, followed by a number indicating the percentage of copper content. For example, “L80”, that is, the alloy consists of 80% copper and 20% zinc.
Multicomponent, containing additional elements called alloying elements, for example, tin, lead, aluminum, etc. The marking of such alloys depends on the elements contained in their composition, and the amount of zinc is calculated by subtracting the share of other elements from 100%. For example, a brass alloy consisting of 63% copper, 3% lead and 34% zinc would appear as "LS63-3".

Depending on the zinc content in the brass alloy, there are:

Red, the zinc content of which is in the range of 5–20%
Yellow, containing more than 20% zinc

Properties of brass

The melting point of brass is 880–950 °C , and the higher the zinc content, the lower the melting point. It is perfectly amenable to pressure treatment, has high mechanical properties, and good corrosion resistance.

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However, for example, bronze outperforms brass in strength and corrosion resistance. It is also unstable in sea water, carbon dioxide solutions and organic acids. An unpleasant property of the alloy is its darkening in the open air; to prevent this, brass products are coated with varnish.

Brass parts do not lose their ductility when the temperature drops, which makes them a good structural material.

Brass and copper are very similar in appearance, and it will be difficult for a non-professional to differentiate between them. The first has increased hardness and wear resistance, but is less refractory . At the same time, brass alloy is much more convenient to process due to its high malleability and toughness.

It is also superior to copper in terms of corrosion resistance, and higher temperatures increase the rate of corrosion formation, the source of which can be high humidity, high levels of ammonia and sulfur dioxide in the air.

To prevent this, brass products must be fired at low temperatures after processing.

Properties of individual types of brass

Wrought brasses are alloys in which the zinc content is less than 10% ; they are also called tombak. Tompak is plastic, does not rust and has low friction force. Tompak welds well with steel and has a golden hue.

Foundry brass is intended for creating products by casting. copper in it varies from 50 to 80%. Such an alloy is not subject to rust, is not subject to deformation through friction with other materials, has good resistance to external force (high mechanical properties), and has no tendency to disintegrate. And also, due to its liquid state, the metal is easy to process, which allows you to pour it into any shape.

Automatic brass is an alloy in which lead is a mandatory element, which makes it possible to obtain short chips when processing a product in an automated mode, which reduces wear on the separating mechanism, increasing the speed of work.

The influence of alloying elements on the properties of the alloy

An alloying element is an element that is added to a metal to change its structure and chemical composition.

Due to aluminum, a decrease in the volatility of the alloy is achieved, since a protective layer of aluminum oxide appears on the surface of the molten brass.
Magnesium is usually used in combination with iron and aluminum to achieve increased strength and corrosion resistance of the product.
Nickel protects the alloy from the negative effects of oxidation processes
Lead is the most common alloying element, which increases ductility and malleability, as well as the quality of metal cutting.
Silicon affects the strength and hardness of the alloy, and in combination with lead it increases anti-friction properties, which makes such an alloy competitive even with tin bronze.
The addition of tin is due to the use of brass in sea water, as it increases the strength and anti-corrosion properties of the metal.

Application of brass

The alloy is one of the most used in the world, it is even called an eternal metal , since it is practically not subject to wear.

Two-component alloys containing up to 20% zinc are used to create coils, spare parts for machines, and thermal equipment. Compounds containing up to 40% zinc are used, for example, to create fittings and stamped products.

The use of multi-component brasses is much wider. They are used in the creation of pipes, ships, aircraft, clocks, springs, etc.

All kinds of insignia and artistic products are made from tombac. Various types of fittings, separators, bearings , and rust-resistant products are made from cast brass. The use of automatic brass is manifested in the creation of fasteners (nuts, bolts, screws, self-tapping screws, etc.), into which brass sheets, strips, and rods are cut.

Brass, which has the property of not being subject to magnetic attraction, is used to create compasses. Due to its high heat capacity, samovars were made from brass back in Tsarist Russia, which are still made from this material to this day.

Church items are also made from it.

Despite its low cost, the alloy is used to create prestigious things , for example, the popular Zippo lighters, the bodies of which are made of brass and then coated with other metals of various colors.

Brass in jewelry

The brass alloy has also found application in jewelry. Jewelers distinguish yellow (medium zinc content), golden (low zinc content), and green brass (high zinc content).

If the alloy consists of 15% zinc and 5% aluminum, then it closely resembles gold, and thanks to its excellent flexibility in polishing, a good craftsman will be able to make jewelry that a non-specialist will never be able to distinguish from a gold product.

This fact is also known to scammers who counterfeit gold. Oxalic acid is used to clean such jewelry.

Alloys marked “L62” and “L68” are the material on which novice jewelers are trained, since in terms of its mechanical characteristics it is as close as possible to gold.

Source: https://kamni.guru/ukrasheniya/metally/latun-chto-eto-takoe-ee-svoystva-i-primenenie.html

Brass production: main features of the process

Brass may vary in its chemical composition. An alloy in which only zinc and copper are present among the components is called two-component. The material is brass, which contains additional alloying elements - multicomponent. In addition to copper and zinc, they may contain elements such as iron, tin, aluminum, etc. Additional components are necessary in order to qualitatively improve certain properties of the alloy.

Classification of brass according to various criteria

The main types of brass are classified according to the alloying elements present in the alloy:

lead brass;
tin brass;
manganese brass;
nickel brass;
silicon brass;
aluminum brass.

Depending on the chosen alloy processing method:

casting brass (used in instrument making, production of bearings, fittings);
deformable metal brass (used in the production of pipes, wire, sheet metal, brass tape).

Depending on the ratio of zinc in the alloy:

up to 20% (but not less than 5%) - tombak (or red brass alloy);
from 20% to 36% - yellow brass alloy.

Why are the properties of brass interesting to manufacturers?

Metal brass alloy is characterized by excellent performance:

resistance to mechanical damage;
ease of processing under pressure;
corrosion resistance.

Brass metal as an alloy is not resistant to carbon dioxide solutions, solutions that contain acids of organic origin. to sea water. An alloy with a low zinc content is more corrosion resistant at normal temperatures.

It is not recommended to use an alloy of copper and zinc in the production of parts and products in contact with sulfur dioxide, ammonia, and water.

Alloy brass production

Individual alloying elements can affect the final properties and quality of the resulting alloy. In the manufacture of brass the following can be additionally used:

tin (affects the final indicators of the alloy’s resistance to corrosion during prolonged contact with salty sea water, expands the range of strength of the material);
manganese (positively affects the strength of brass and its anti-corrosion qualities);
lead (used in the manufacture of brass; if the finished alloy is subsequently subjected to metal cutting, this may not have the best effect on its mechanical strength);
nickel (allows you to increase the durability of brass during its exposure to various environments);
aluminum (allows you to reduce the volatility of zinc due to the formation of a durable oxide film on the surface of the alloy);
silicon (provides brass with better weldability, but reduces the hardness of the resulting alloy).

How brass is obtained in production

The production of brass is carried out according to technological maps developed in the zinc and copper industries. Alloys are often obtained by recycling raw materials: copper billets, zinc waste, etc. Recycled raw materials are especially often used during the casting of brass with additional elements.

Brass casting is a complex process made possible by the presence of different types of melting furnaces in production. Modern low-frequency (induction) furnaces, equipped with an additional magnetic core, are in particular demand among technologists.

It must be taken into account that during the melting process of metals, their partial evaporation occurs. Therefore, casting can only be done with powerful industrial exhaust ventilation. There is also a risk of the components of the future alloy catching fire during the casting process - it is necessary to constantly monitor the temperature in the melting furnace to eliminate the possibility of overheating.

Before starting to manufacture brass of a certain composition, the furnace must be completely cleaned. Then the copper will be heated in it to a state of red heat, after which zinc blanks are added. To prevent the oxidation of zinc, copper in alloys is always added first.

In order to obtain cast brass, the alloy molten in a furnace is poured into pre-prepared molds. As a result, the alloy solidifies and forms round, flat ingots. After the casting process is completed, further work can be done with the alloy. For example, subject it to heat treatment in order to increase strength indicators, perform aging and hardening of the alloy, and deform the ingots if necessary.

Main areas of use of brass alloys

In mechanical engineering, brass alloys are used for the production of adapters, bushings, and cooling systems for engines. In construction, this alloy is often used in the manufacture of pipe fittings and individual elements of plumbing equipment.

Brass often becomes a material popular in the design environment: its presentable appearance allows numerous interior components to be made from alloys.

April 16, 2017

Source: https://tdspecstal.ru/articles/brass.html

What is brass made from?

Brass is a double or multi-component copper-based alloy, where the main alloying component is zinc, sometimes with the addition of tin (less than zinc, otherwise you will get traditional tin bronze), nickel, lead, manganese, iron and other elements. According to the metallurgical classification, it does not belong to bronze.

History and origin of the name [edit | edit code]

Despite the fact that zinc as a chemical element was discovered only in the 16th century, brass was known even before our era [1] [2]. The Mossinoiki obtained it by alloying copper with galmey [3], that is, with zinc ore. In England, brass was first produced by alloying copper with zinc metal, a method patented by James Emerson on July 13, 1781 (British Patent No. 1297) [4] [5]. In the 19th century in Western Europe and Russia, brass was used as counterfeit gold.

In the time of Augustus in Rome, brass was called orichalcum (Latin aurichalcum - literally “golden copper”), and sesterces and dupondiums were minted from it. Orichalcum gets its name from the color of the alloy, which is similar to gold. However, in the Roman Empire itself, before the conquest of Britain in the 1st century AD. e.

brass was not produced because the Romans did not have access to sources of zinc (which appeared and began to be developed only after the formation of the province of Britain within the empire); before that, zinc could only be imported by Hellenic and Roman traders; there was no own mining in continental Europe and the Mediterranean [6].

The total world demand for zinc for the production of brass is currently about 2.1 million tons. At the same time, 1 million tons of primary zinc, 600 thousand tons of zinc obtained from waste from our own production, and 0.5 million tons are used in production secondary raw materials [ source not specified 540 days ]. Thus, more than 50% of the zinc used in brass production comes from waste. Technical brass usually contains up to 48-50% zinc.

Depending on the zinc content, alpha brass and alpha + beta brass are distinguished. Single-phase alpha brasses (up to 35% zinc) are easily deformed in hot and cold states. In turn, two-phase alpha + beta brasses (up to 47-50% zinc) are low in plasticity in the cold state. They are usually hot worked at temperatures corresponding to the alpha or alpha+beta phase region.

Compared to alpha brass, two-phase brasses have greater strength and wear resistance with less ductility. Double brasses are often alloyed with aluminum, iron, magnesium, lead or other elements. Such brasses are called special or multi-component. Alloying elements (except lead) increase strength (hardness), but reduce the ductility of brass. in brass, lead (up to 4%) facilitates cutting and improves anti-friction properties.

Aluminum, zinc, silicon and nickel increase the corrosion resistance of brass. Adding iron, nickel and magnesium to brass increases its strength.

Physical properties [edit | edit code ]

Density - 8500-8700 kg/m³.
Specific heat capacity at 20 °C is 0.377 kJ kg −1 K −1 .
Electrical resistivity - (0.07-0.08)⋅10 −6 Ohm m.
Not ferromagnetic
The melting point of brass, depending on its composition, reaches 880–950 °C. As the zinc content increases, the melting point decreases.
Brass can be welded quite well by various types of welding, including gas and shielded arc welding, and can be rolled. Brass welding technologies are described in the relevant literature. Although the surface of brass, if not varnished, turns black in air, it resists the action of the atmosphere better as a mass than copper. It has a yellow color and is highly polished.
Bismuth and lead have a detrimental effect on brass, as they reduce the ability to deform when hot. However, lead alloying is used to produce free-flowing chips, which makes them easier to cut [7] .

Phase diagram of Cu - Zn [ edit | edit code]

Single-phase brasses are characterized by high ductility; The β'-phase is very brittle and hard, so two-phase brasses have higher strength and lower ductility than single-phase brasses.

zinc in copper affects the mechanical properties of annealed brass.

With a zinc content of up to 30%, both strength and ductility increase simultaneously. Then the plasticity decreases, first due to the complication of the α-solid solution, and then there is a sharp decrease due to the appearance of a brittle β'-phase in the structure. Strength increases up to a zinc content of about 45%, and then decreases as sharply as ductility.

Source: https://crast.ru/instrumenty/iz-chego-delaetsja-latun