How to get bronze

How to turn stone into gold with bronze powder

Paint containing bronze powder is successfully used by decorators, designers and ordinary people to transform interior items. This composition can give a metallic shine to almost any material. What kind of bronze powder is this that will turn a brick into metal?

Where is it used?

It is a dispersed powder that is obtained by grinding copper or copper-zinc alloys with a slight addition of iron and aluminum. Paraffin or stearic acid must be added to the powder, which prevent oxidation of the particles and their sticking together.

Based on their chemical composition and purpose, there are several brands of powder for:

• paints (BOD);
• offset printing (BPO);
• tool making (BPI);
• printing (BPP).

Bronze powder has a layered structure. Each layer is composed of scaly plates. Color - from yellow-golden to deep red or brass. The saturation of the shade is determined by the percentage of zinc.

Powder production

The production of powder takes place using industrial methods by repeatedly crushing bronze powder. After several stages of grinding, its separation is carried out in ball mills or pneumatic units.

Paints and varnishes based on bronze powder have significant hiding power. The quality of painting depends on the size of the fraction. The highest quality is powder, which, when sifted, forms a residue of no more than 1% (on sieve No. 0.045). To obtain a powder with maximum coverage, it is necessary to use bronze alloys rather than pure copper. With one gram of such powder you can cover up to 4500 cm² of surface.

Areas of application

Bronze powder is used in decoration, printing, in the production of paints and coatings, various labels, and in the cosmetics industry. With the help of paint, which has been injected with bronze powder, you can impart a metallic shine and a characteristic texture to products made of steel, plaster, cardboard, glass, concrete, and plastic.

This product is also used when painting components of systems that require additional protection:

• tanks, system parts in industry;
• radiator systems, heating batteries;
• parts of boiler systems that protect against elevated temperatures;
• various port structures and parts of ships that are constantly under water;
• fences, bridges.

Methods for preparing formulations

It is necessary to mix the powder with the binder. The tincture will determine the main characteristics of the future coating, accordingly the possible areas of application, as well as the final cost. Tincture can be:

• varnishes on metal or wood for exterior and interior use;
• epoxy enamel;
• some types of adhesives;
• egg powder dissolved in water;
• gelatin.

The binder component is selected based on the type of surface being treated. For example, when treating wood products that will be used indoors, the tincture should be a clear interior varnish.

The color depth of the finished coating is determined by the ratio of the amount of bronze powder and the binder base. The deeper the color, the more powder you need to take. The consistency of the ready-to-apply composition resembles thick sour cream. This paint, with a bronze powder content of about 40%, will provide a reliable and effective coating.

What proportions should be observed? If varnish or drying oil serves as a tincture, then take two parts of powder for 4 parts of the base. If the solution turns out to be too thick, then turpentine, white spirit or solvent are used for dilution.

When using a spray bottle to apply a bronze layer, mix the solvent and powder in equal proportions. When using a brush, you need to take two portions of foundation per serving of powder.

Coating

To give the product a metallic shine, you can make the composition yourself or buy it ready-made in aerosols.

Before applying the coating, any product must be cleaned of contaminants. Wooden surfaces are pre-sanded, and metal surfaces are treated to prevent rust. Often craftsmen prefer to remove the old coating:

• by mechanical cleaning with a grinding attachment or brush (applicable to metal surfaces);
• sandblasting (cleaning metal surfaces under the influence of grains of sand);
• chemical cleaning (special compounds react with the old coating);
• thermal cleaning using a hair dryer.

Then the varnish or paint is applied in a thin layer, which is literally rubbed over the surface. To obtain the thinnest possible layer, use a sponge or stiff brush.

When using nitro varnish as a tincture, apply bronze paint as quickly as possible until the composition sets.

If the coating is to protect the product from corrosion, then it must be primed before applying paint.

Coating of smooth products

There are usually no problems with applying paint to equal surfaces. The main issue in such work is the determination of the connecting component. If the product will be exposed to aggressive influences, then use varnishes for external use.

Such surfaces can be coated with a brush or even spray equipment. Compositions in aerosol cans are also suitable for applying a high-quality layer.

Sputtering

Products with simple relief can be decorated using the spraying method. It is worth starting staining with this method again with preparation. It is necessary to apply varnish or glue to the degreased surface of the product. When applying the binder component, care must be taken to ensure that no lint or other foreign bodies remain on the product.

Bronze powder is first poured onto gauze folded in several layers, which is then tied in a knot. When the bundle is shaken over a varnished product, small particles of powder are securely attached to it. This application allows you to obtain a very durable and beautiful metal-like coating.

Application on difficult terrain

To apply high-quality paint on products with complex relief, you need to have some skill.

How to apply paint in this case? The secret is simple - it is better to use oil varnish as a binding base. To give it a noble golden brown hue, you can add a little brown oil-based paint.

This composition is applied to a fat-free product. The powder, as with spraying, is formed into a slide on gauze and a knot is tied.

Of course, this method allows you to achieve high-quality and effective coverage, but for beginners it is better to use a simpler method. To do this, prepare a coloring composition with bronze powder in advance, and then simply apply it with a cloth swab or sponge.

How to get a patina effect

The pinnacle of craftsmanship is considered to be giving relief products a patina effect. How to do it? First, the prepared composition is applied to a clean surface. Wait until the layer dries completely. Then you should apply a layer of stain or liquid bitumen varnish, also filling all the relief depressions.

Without waiting for this layer to dry, use a sponge or cotton cloth to wipe all convex surfaces. Excess varnish in the recesses must also be removed. After complete drying, the product can be used.

To achieve the effect of a polished surface, some craftsmen additionally tint the convex parts with a bronze composition.

Bronze powder in printing

Bronze fine powder is widely used in printing. Thanks to it, labels, advertising and packaging materials are produced with a unique shine and a particularly rich color. This technology is called bronzing.

The process involves applying flakes of bronze powder to a print that has been treated with adhesive paint. Due to the layered structure of the powder, as well as the large particle size, multiple refraction and reflection of light occurs. This reflection gives the enchanting mother-of-pearl effect.

Previously, foil, gold varnish or metallic paints were used to decorate labels. But bronzing gives an incomparably better effect at lower costs. The popular foil stamping is twice as expensive as bronzing.

Advantages and disadvantages

Advantages of bronze powder for paints:

1. This powder actually contains bronze, which means it can protect individual parts or entire surfaces from aggressive environments.
2. This coating has high resistance to ultraviolet radiation and resistance to moisture and, as a result, extends the service life of products and individual components. Objects treated with a bronze composition have a guaranteed service life of up to three years when used under water, and up to seven years when used in air.
3. You can coat brick, concrete, metal, wood, plaster, paper and other surfaces with bronze powder.
4. The bronze layer is very thin, but durable and resistant to abrasion. It's difficult to remove.
5. Bronze powder based paint is non-toxic, dries quickly and adheres well.
6. Thanks to this coating, you can decorate the interior without much expense.

Flaws:

1. This is an explosive substance that must be stored in a tightly closed container away from open flames.
2. The composition cannot be applied to surfaces treated with nitro enamel, acrylic and oil paints, or varnishes. After application, the base coating may peel off and bubble.
3. When applying acrylic paint with bronze powder, rust often occurs.

Ways to remove random paint stains

It is impossible to completely protect clothing or interior items from accidental paint. The most careful craftsmen need to know how to remove bronze composition. If the stain has already dried, it can be removed with the same solvent in which the powder was diluted.

If a ready-made composition was applied, the basis of which is unknown, then you can apply a drop of sunflower oil to the stain. Leave the applied oil on for about 10 minutes, then wipe the stain with a cotton napkin. Remove fresh stains with nail polish remover without acetone.

Source: https://tsvetmet.wordpress.com/2020/01/13/%D0%BA%D0%B0%D0%BA-%D0%BF%D1%80%D0%B5%D0%B2%D1% 80%D0%B0%D1%82%D0%B8%D1%82%D1%8C-%D0%BA%D0%B0%D0%BC%D0%B5%D0%BD%D1%8C-%D0% B2-%D0%B7%D0%BE%D0%BB%D0%BE%D1%82%D0%BE-%D0%B1%D1%80%D0%BE%D0%BD%D0%B7%D0% BE/

Bronze casting technology at home

Bronze is often used in the manufacture of decorative metal products. This material produces attractive products that retain their decent appearance for a long time.

Bronze casting is considered one of the most popular foundry processes and has been used for hundreds of years to make various products from this metal.

To understand how suitable this material is for casting and how to work with it correctly, you need to have general information about the metal itself and how it is processed.

General characteristics of the metal

Bronze is an alloy that may contain tin, copper and other components. Foreign impurities include zinc, aluminum, beryllium, lead, nickel or silicon. If we talk about composition, bronze can be divided into two groups:

1. Tin alloys. The material may consist of two or several components. Tin is the second most abundant component of the alloy.
2. Tin-free alloys. The composition may include aluminum, lead, silicon, lead or beryllium. These components change the characteristics of the alloy.

The characteristics of the bronze alloy include:

1. Density. This indicator depends on the tin content in the composition. Average number 9.1 kg/cu.m. cm.
2. The temperature at which metal melts. Varies depending on the components of the composition. Range 880–1060 degrees Celsius.
3. Heat capacity - 0.385 kJ / (kg*K).
4. Electrical conductivity - 0.176 μOhm*m.

If you want to change any of the characteristics of the alloy, a certain amount of foreign impurities is added to its composition.

History of technology

Historians and archaeologists claim that bronze casting began to develop more than 10 thousand years ago. At the beginning of the history of the appearance of this alloy, it was used for the production of tools and primitive jewelry. Previously, the alloy was used only for industrial purposes. At the moment, bronze is used for the manufacture of decorative items, fences, movable fences, chandeliers, sconces, and sculptural compositions.

The moment of the most important peak in the manufacture of bronze products is the European Baroque period. During this period, people decorated their homes and estates with decorative elements made from this alloy.

Main stages

Bronze casting involves a technological process that requires the use of special equipment and compliance with certain production stages:

1. First of all, a drawing of the future workpiece is prepared.
2. A connection to the gating system model is created. This is done by soldering or gluing.
3. An injection mold is made from refractory mixtures.
4. The form is freed from the model composition. To do this, it is heated with steam or lowered into a container with hot water.
5. Using a centrifugal machine, molten bronze is poured into a mold.
6. The future workpiece is allowed to cool on its own.

For further processing of the bronze part, the mold is broken. The workpiece is washed using chemical compounds.

Bronze casting technologies

Bronze casting can be divided into several types depending on the technological process and the use of casting machines. Induction furnaces are used to melt the alloy. The metal itself is coated with flux.

Injection molding

During the vacuum suction process, the molten metal begins to be drawn into the mold. Next, the workpiece begins to cool, which occurs from the edges to the center. It uses a container with thin walls as a crystallizer. It is cooled with water. After cooling, the workpiece itself moves away from the mold.

Centrifugal casting

Centrifugal casting of bronze is used for the manufacture of cylindrical and cone-shaped parts. These include O-rings, bushings for industrial equipment and other parts. Worm wheels and gears are manufactured using centrifugal technology. The technological process involves rotation of the mold, due to which the molten metal is compacted.

Artistic casting

Bronze artistic casting technology is used to create decorative elements. These include various sculptures, lamps, grilles, fences, and souvenirs. Stages of artistic bronze casting:

1. Initially, a drawing of the future workpiece is made.
2. Next, the master creates a mold into which the molten metal will be poured.
3. The feedstock—the charge—is melted.
4. The casting mold is filled with molten metal.
5. Cooling process.
6. Removing the workpiece from the mold.

The last stage is the cleaning and further processing of the part. If the design is composite, individual parts are initially created and processed. After this, they are combined into one structure. The seams are cleaned and treated with protective compounds. By correctly performing the technological process of creating decorative elements from bronze, you can avoid mistakes and reduce the quality of the finished product.

Casting at home

Experienced metallurgy masters practice bronze casting at home. To carry out this process you need to purchase:

• bugle;
• forceps;
• charcoal or coal;
• crucible in which metal will be melted.

A gas burner is often used as a heating element for melting a bronze alloy. This is due to the fact that bronze can be melted at a low temperature. This way you can save on the purchase of an induction furnace.

Casting at home

Creating a casting mold

Casting bronze at home requires the correct production of casting molds. The molding mixture should consist of a mixture of sandstone, coal dust, and clay. Stages of mold making:

1. The molding mixture is poured into a wooden box called a flask. It is compacted from above with weak blows.
2. Next, a model of the future workpiece is immersed in the molding mixture.
3. On top there is another box (flask). The molding mixture is poured into it. It's being compacted.
4. Next, the master divides the form into lower and upper halves.

How to properly pour molten bronze into a casting mold

Bronze casting at home requires special preparation of casting molds. It is necessary to remove air from them in order to obtain durable castings without defects. The molds must be spun in an electrically driven centrifuge. After this, the molten metal can be poured.

How to get better quality castings

The casting quality can be improved. You need to use another modified technology. In this case, wax is used. It is used to make molds into which the castings will be poured. You can use paraffin. To make such a model, you need to use a ready-made mold that is heated in boiling water.

Casting bronze into a steel mold at home
Bronze casting has been known for many hundreds of years. Using this technological process, decorative elements, fences, lamps and sculptures are made. The composition of bronze includes various components that affect the characteristics of the alloy.

There are different types of making bronze castings, which involve different technological processes.

Source: https://metalloy.ru/obrabotka/lityo/bronzy

Melting point of bronze

Many people today are trying to master industrial production technologies at home. Provided that the sequence of certain manipulations is followed and the necessary equipment is available, it is sometimes possible to solve very complex problems.

For example, you can easily melt metals and create bladed weapons or exclusive jewelry with your own hands. To do this, you need to know to what temperature the metal needs to be heated and how best to do it.

This article will tell you what the melting point of bronze is, what you need to take into account if you want to subjugate this metal.

What is bronze? This is an alloy consisting of a main component (copper) and an additional alloying element. Depending on what acts as an alloying additive, several grades of the material being described are distinguished, therefore each type of bronze has its own melting point. The physical and chemical properties of bronze depend on the percentage of additional components. Its marking helps to understand what impurities are contained in the alloy.

All bronze compositions can be divided into two large groups:

Tin alloys are a type of bronze that contains tin as an alloying element. This metal is stronger than copper, but it is fusible. The combination of copper (80%) and tin (20%) is the first alloy that humanity has learned to create. With its help, church bells were cast in Rus'. The metal sounded good, but was fragile. Therefore, there was a need to look for more advanced alloys.

Tin-free alloys do not contain brittle tin. Beryllium, silicon, lead and aluminum can be used as alloying additives. Depending on which of the listed metals is combined with copper, the alloy acquires its physical and chemical properties.

For example, beryllium makes it possible to create alloys whose strength characteristics are much superior to high-quality steel. The addition of silicon makes bronze more resistant to mechanical friction.

Lead helps to form high resistance to corrosion, aluminum improves the friction characteristics of the alloy.

The process of melting bronze must begin with studying its composition. All tin grades melt at a temperature of 900–950°C, tin-free grades melt at a temperature of 950–1080°C.

Note! When casting, another indicator of the alloy is taken into account - its viscosity. Tin bronze has a higher temperature than brass, so when heating it it must be very overheated. Then, after cooling, the described brand gives minimal shrinkage, so this type of bronze is ideal for shaped casting.

Many of us wonder whether the process of melting the described alloy is possible at home. It is impossible to recreate industrial casting. Since bronze has a high melting point, special conditions are required to work with hot metal.

You can try to master small casting, which allows you to create jewelry or small crafts. To carry out this process, you will have to allocate a separate room, as well as take all fire safety measures and provide high-quality ventilation.

Large bronze parts can be made where there is an earthen or concrete floor (this could be a garage with good forced ventilation).

To work you will need certain equipment and special tools. Only a muffle furnace will allow casting (the presence of a thermostat will greatly simplify the solution of the task). For large pours, you will have to install a forge. You can melt metal in a cast iron container that is shaped like a spout. It helps to gently pour the molten metal into the mold. This cast iron container is called a crucible.

The crucible is removed from the furnace using long tongs and a special hook. There should be a casting mold at hand. Charcoal is best suited for lighting a muffle furnace, and coke for a forge.

Casting process

The process of casting bronze is extremely simple. The oven heats up to certain parameters. Let us remind you once again that to melt tin alloys it is necessary to heat the furnace to a temperature of 900–950°C; the melting temperature of tin-free alloys is an order of magnitude higher – 950–1080°C.

Melting of any bronze composition must begin with calcination of the mold for pouring in a muffle furnace or in a forge. To do this, the oven is first heated to a temperature of 600°C. Then the mold is immersed in it, after which the temperature in the oven must be increased to 900°C. The mold should spend a couple of hours in the oven. After the timer ends, the mold is removed from the oven and cooled to a temperature of 500°C.

The bronze is placed in a cast iron tray and sent straight into a well-heated oven. After the alloy has melted, the metal must be kept in the oven for another five minutes. This way it will warm up well, which means it will be easy to ensure high-quality filling of the casting mold. The crucible is removed from the furnace using a hook, and the process of pouring the molten alloy into the mold is ensured with tongs. It is important to pour the metal in a thin, continuous stream. This is the only way to prevent the process of blurring the shape.

How to properly pour molten bronze into a casting mold

Pouring molten bronze into a mold is a real science. Filling out a large form will be easy. The liquid alloy, under the influence of gravity and its own weight, will itself be evenly distributed throughout the container and displace all existing air.

There will be a certain problem with filling out small forms. The fact is that air prevents the uniform redistribution of the alloy over all planes.

Therefore, often melting bronze at home does not allow creating high-quality products.

Is it possible to solve a similar problem on my own? Yes, if you have a centrifuge at hand. Centrifugal force will displace the air and allow the alloy to be evenly redistributed over the entire area of ​​the mold. It is necessary to act according to this plan very quickly, before the bronze has time to harden.

You need to remove the pouring from the mold when the alloy has completely hardened. The surface of the workpiece will be rough, and in some places metal deposits will definitely appear. Such defects are eliminated by mechanical grinding. If the oven has been heated correctly, the amount of mechanical grinding will be minimal.

Creating a casting mold

Given the fact that each type of bronze has its own melting point, it is important to have on hand a mold that can withstand the highest heating point of the alloy being described. It is difficult to create it with your own hands at home, but you can try if you carefully study the following instructions.

First you need to create a molding box (foundry workers call it a flask). Its dimensions are one and a half times larger than the dimensions of the future part. The flask is assembled from unplaned boards according to the following scheme: first, the upper frame is knocked down (outwardly it looks like an ordinary box without a bottom and top, but with two crossbars in the middle), then the lower frame (box with a bottom) is knocked down.

Then they begin to create the molding soil. It has a special composition: 75% fine-grained sand, 20% clay and 5% coal dust. All ingredients are combined and mixed thoroughly.

The next stage is making a model that will help form a mold for future casting. Experts recommend making it from wood. The further process is reproduced according to the following algorithm.

1. The wooden model is first generously sprinkled with talcum powder, and then carefully placed exactly halfway in the bottom drawer of the flask.
2. Then it is filled to the top with ready-made molding soil.
3. The entire resulting composition is generously sprinkled with graphite.
4. After this, the lower part of the flask (with a bottom) is covered with an upper frame (without a bottom).
5. A metal cone is inserted into the upper frame, the narrow part of which should touch the surface of the wooden model. The cone will allow you to form a sprue - a part through which molten bronze will be poured.
6. The top box is also filled to the top with molding soil. The filling is carefully compacted with a special mortar.
7. After this, the metal cone is carefully removed. Using a sharp knife, the upper flask is removed from the lower frame along with the molding sand. A wooden blank is removed from it. After all the manipulations performed, there should be indentations on both flasks that accurately copy the geometry of one half of the wooden model.

Note! At this stage, you can use a knife to correct slightly crumbling lines. If some of the earth sticks to the model, its deficiency in the flask is made up for. The excess is simply removed.

1. We leave the lower and upper parts of the flask until completely dry, and then connect them together so that there is no gap between them. The bronze casting mold is ready.

Using this form, it is possible to create bronze products that do not have a clear pattern and small details.

How to get better quality castings

Even at home, you can produce higher-quality casting if you use a special method for creating a mold for casting. The basis is a model that exactly resembles the one that will need to be smelted from bronze. It is made from wax or paraffin.

• First, a plaster cast consisting of two halves is taken from the model. The parts of the cast are connected to each other with gypsum mortar.
• After drying, the resulting form is filled with liquid paraffin through a specially left hole.
• When the paraffin hardens, the gypsum shell is removed. A figure of frozen paraffin should remain.
• It is placed in a heat-resistant mass and a one-piece mold is formed for casting. Foundry masses are sold today in construction stores. Be sure to leave a hole in the mold for draining paraffin and pouring bronze.
• Then the one-piece mold must be placed in boiling water. It will heat up and melt the paraffin or wax. Through a special hole designed for pouring liquid alloy (future sprue), you need to drain the molten wax. After this, the mold for creating a higher-quality casting will be ready. Making a mold in this way allows you to obtain a bronze casting that has a clearer outline and finer details.

Recreating the process of melting bronze at home is not so easy, but if you are faced with a similar task, this article will help you solve it. The main thing is to always remember safety precautions, be able to distinguish between types of alloys, and know at what temperature each of them melts.

Source: https://svarkalegko.com/materials/bronza-i-eyo-svojstva-temperatura-plavleniya.html

Bronze casting

Bronze casting has been used since ancient times. For many centuries, copper alloys (bronze, brass) were used to make tools, hunting and jewelry.

Improvements in foundry technology have led at the present stage to the emergence of many methods for casting metals, especially non-ferrous ones. The technological capabilities of bronze casting make it possible to obtain not just objects, but works of art, which have been considered the height of perfection since ancient times.

Bronze casting

The developed technologies make it possible to melt copper alloys not only in industrial production conditions, but also at home, in small workshops.

Main stages

To obtain high-quality cast products, strict adherence to the technological sequence is required. The casting process is as follows:

1. Making a model or copy according to a sketch or drawing. Materials for the model are easily melting at low temperatures: stearin, paraffin, wax and others. The ability to completely fill the volume of internal space in a mold has made these materials widely used.
2. The gating system is attached to the model by gluing, soldering or mechanical fastening. Thus, feeders, channels, vents and other elements are formed.
3. The production of injection molds is made from a refractory mixture. The main composition of the mixtures is fireclay or alumina clay and quartz sand.
4. The mold is released from the model composition by heating with steam or immersion in heated water.
5. Typically, bronze casting is carried out by free pouring using centrifugal machines, excess or insufficient pressure (vacuum).
6. Cooling is done in air or using a thermostat.
7. After cooling, the model form collapses. The gating system is cut off. The workpiece is sent for cleaning using washing or chemical compounds.

Artistic casting of bronze and brass involves obtaining the smoothest possible surface, so fairly hard materials are used to recreate the model:

1. • wood;
   • gypsum;
   • Ivory.

To obtain the smoothest possible surface, it is subjected to elimination of porosity by puttying, priming and varnishing.
Casting models are made split; one-piece - suitable for casting products of simple shapes; special for parts with a rather complex configuration.

There are two types of casting molds: disposable and reusable. It all depends on the material from which they are made. If a clay-sand mixture is used for manufacturing, then to maintain its shape, metal flasks are required to prevent the destruction of the mixture.

Reusable molds are made of steel with a horizontal or vertical parting line. To increase the casting ability of a copper alloy, lubricants are used to prevent the occurrence of welds, burns and other defects.

Melting points

The melting point of bronze directly depends on the filling of the alloy with chemical elements. After all, refractory elements can act as alloying components. Thus, the maximum temperature for casting bronze is 1350 °C.

Marking of alloying elements added to copper alloys:

• aluminum (A);
• beryllium (B);
• iron (F);
• silicon (K);
• manganese (Mc);
• nickel (N);
• lead (C);
• selenium (O);
• titanium (T);
• zinc (Z).

To divide bronze alloys, two definitions are used: tin-bearing and tin-free bronzes. The melting point of a material suitable for casting, depending on its chemical composition, is given in the table.

Alloy, designation	Temperature for casting, °C
BrOF4-0.25	1300
BrOTs4-3	1250
BrOTsS4-4-4	1200
BrAZH9-4	1200
BrA9Mts2L	1150
BrA10Zh8L	1190
BrA11Zh6N6	1185
BrAZhS7-1.5-1.5	1150
BrS3O	975
BrA5	1200
BrKN1-3	1050
BrBNT1.7	1050
BrAMts10-2	1150
BrKMts3-1	1150
BrMts5	1150
BrB2	1100
BrSN60-2.5	1100

This is not a complete list of cast bronze alloys.

If bronze smelting is done at home, then special attention should be paid to the melting point of the alloy. Tin bronzes do not need to overcome the thousand-degree threshold. They need 900°C - 950°C. Tin-free alloys already require 950 °C - 1100 °C.

Parts produced from bronze by centrifugal casting

When smelting bronze parts, it is worth considering their high viscosity. Therefore, for high-quality casting, they should be heated above the melting point by about 100 degrees. Bronzes have minimal shrinkage, which does not exceed 1.5%. This characteristic is an advantage over brass and makes it possible to obtain shaped castings.

For comparison, you can look at the melting point of brass. There are two categories of brass: two-component and multi-component brass. The two component alloys contain zinc in addition to copper. Its amount affects the melting point, which is in the range 880°C - 965°C.

For multi-component temperature conditions increase to 895 °C - 1070 °C due to the introduction of alloying components with a high melting point.

Bronze casting technologies

Melting, like cutting, is a widespread operation for producing parts. For melting, it is recommended to use induction melting or crucible heating furnaces. The choice is determined by economical electricity consumption.

To preserve the chemical composition of alloys, fluxes are used. With their help you can:

• Protect the outer layer of the melt surface:
  1. from oxidation;
  2. increase the volume of suitable melt;
  3. exclude non-metallic components;

• Degas the composition due to which the formation decreases:

To obtain smooth surfaces on the casting and ease its removal after cooling, non-stick paints are used. Their use ensures:

• mold lubrication;
• protection from destruction upon contact with the melt;
• no burns.

Injection molding

Injection molding occurs when exposed to excess or insufficient (vacuum) pressure. The press principle is used to supply the melt under excess pressure. The piston is subject to force from a hydraulic or pneumatic system. The high feed rate coupled with high viscosity creates high pressure to completely fill the mold. The resulting castings have high precision and a fine-grained structure.

Due to vacuum suction, the melt is drawn into the mold of the crystallizer. Cooling occurs towards the center of the mold. The required amount of melt is drawn in over a certain period of time.

A crystallizer is a container with thin walls that are cooled with water.

After normal (atmospheric) pressure is restored, the excess melt drains off. After cooling due to shrinkage, the part is independently removed from the mold. Automation of the vacuum suction process allows you to fill the mold in a minimum amount of time, down to 0.1 seconds.

Finished bronze product

Centrifugal casting

It is advisable to use centrifugal casting, pouring bronze and brass in the manufacture of parts such as rotating bodies. The formation of parts occurs on machines with horizontal and vertical axes of rotation. On machines with horizontal pouring the following is cast:

On machines with vertical pouring the following is cast:

• gears;
• worm wheels;
• propellers.

Centrifugal casting

The technology is based on centrifugal force, which is generated when the mold rotates. The melt is compacted under the influence of forces, displacing third-party components.

Artistic casting

Modern trends dictate the use of casting not only in the production of parts for mechanisms and assemblies, but also in the production of interior elements. Thus, using artistic casting technology it is possible to produce:

• bas-reliefs, sculptures;
• elements of fences, gratings, gate fences;
• souvenirs;
• lamps, sconces;
• interior elements.

The stages of technology for producing castings are as follows:

• making a model;
• mold making;
• preparing the form;
• melting of the charge;
• preparing the melt for pouring;
• cooling;
• demolding;
• stump;
• cleaning and presentation.

Finished castings, according to the master’s plan, are combined into a single product if it is multi-component. After which they can be chrome-plated, nickel-plated, covered with patina and other metals.

Casting at home

Many craftsmen cast bronze products at home. These are mainly interior parts and figure casting. In addition to the basic devices, you need to purchase auxiliary tools and materials. Among them:

• forceps;
• coal (wood, stone);
• crucible;
• horn

Melting furnace used at home

The forge supplies the air necessary to maintain the combustion of coal, which creates the necessary temperature for melting bronze. Using tongs, the crucible is removed from the heating chamber and the melt is poured. Due to the fact that bronze melts at low temperatures, the melting furnace can be replaced with a gas cutter (autogen) or a blowtorch.

Artistic bronze casting involves carrying out work in a separate room, which must be equipped with fire extinguishing equipment and supply and exhaust ventilation. In addition, it is necessary to organize storage areas for tools, devices, materials, as well as organize conditions for personal hygiene.

Bronze products, after they are removed from the mold, look like a black, charred, melted piece of metal. To give it a presentable appearance, at the initial stage, use a metal brush or a machine with attachments made of abrasive material.

The fairly good fluidity of bronze, unlike brass, does not contribute to complete filling of the mold when manually casting at home, as a result of which the pattern on the surface of the casting is unclear.

To eliminate this defect, craftsmen use embossing. It helps to give the final look to the product if it has a lot of openwork ornaments. Minting takes quite a lot of time.

Source: https://stankiexpert.ru/spravochnik/litejjnoe-proizvodstvo/litye-bronzy.html

How to make bronze in Minecraft

:

• Bronze in Industrial Craft2
• Bronze in Forestry

In pure Minecraft there is iron, there is gold, there are diamonds. But for some reason they forgot about bronze. Such a popular alloy, which has become a strategic material more than once in history - and overboard! What an injustice. But for every action (respect to Newton for this wisdom) there is a reaction, and even more so for inaction. Therefore, the guys who created “Industrial Craft2” rustled and added bronze. Of course, to make this alloy, you also need to rustle and install the mentioned mod.

Bronze in Industrial Craft2

Bronze in Minecraft is a concept that includes dust, ingots and blocks (made from this material, of course). Dust is the basis from which other bronze items are crafted, so it is logical to first learn how to mine it. In order to make it, according to the old version, you only need tin and copper dust, which should be arranged like this.

The new option offers crafters an alternative. If you want, you can be content with only this recipe in Minecraft. If you want, you can use purified or crushed copper ore as a replacement for copper dust. You can also replace tin dust with purified or crushed tin ore. Yes, you can see everything in the illustration yourself.

If you already have an ingot, and you also have a crusher in your Minecraft closet, an additional recipe becomes available to you.

Having dust makes you practically a bronze tycoon in Minecraft - you can now smelt ingots. The image shows exactly how the melting process occurs.

Having learned how to make pigs, you have the right to ask a not entirely chronologically logical question: why do you even need bronze in Minecraft? Although, most likely, you yourself understand that you can do many useful things with its help. Yes, yes, it is possible. And here they are, things:

• Rails
• Composite ingot
• Wrench
• Helmet
• Leggings
• Boots
• Cuirass
• Bronze block

And once again illustration comes to our rescue. She demonstrates exactly how to craft these items in Minecraft.

A bronze block is crafted from nine ingots. Its only practical use is compact storage of material. As usual in Minecraft, if you need ingots, we crush the block, that is, we perform the reverse process.

Bronze in Forestry

Ingots in Minecraft can be made not only in Industrial Craft2. You can craft them by installing the “Forestry” modification. In fact, with this mod it is even more profitable to mine the alloy. Here the ingredients are no longer dust, but tin and copper ingots. Simple mathematics leads to the conclusion that this strategy gives twice as much bronze.

Some of the ingots can be returned back if you repair broken items in Minecraft. Like, for example, in this screenshot.

In this mod, an alloy of tin and copper is used for crafting:

• Durable machine
• Wrench
• Pickaxes
• Shovels
• Biofuel engine, etc.

This metal is a component in creating the Minecraft light bulb factory!

Source: https://azminecraft.ru/publ/3936-kak-v-minecraft-sdelat-bronzu.html

Bronze - composition, properties and production of the alloy

Bronze as a material for the manufacture of products for various purposes has been used by man since ancient times.

And in our time, this alloy has not lost its high popularity: it is actively used both by manufacturing enterprises that make elements of various mechanisms and structures from it, and by home craftsmen who decide to engage in artistic casting.

However, before you start working with this copper alloy, you need to carefully study its characteristics, as well as become familiar with the methods of its processing.

Bronze rods produced for further use in various industries can be round, square or hexagonal in cross section

Features and Benefits

Bronze, which is a non-ferrous metal, is a copper-based alloy. Since ancient times, bronzes have been most widespread, the chemical composition of which, in addition to copper, contains tin. Instead of tin, various grades of bronze may contain elements such as beryllium, iron, aluminum, lead, silicon, etc.

chemical elements in cast bronzes are regulated by GOST 493-79, 613-79

The high popularity that bronze has enjoyed for many centuries is explained by such advantages as:

• high hardness and strength when comparing this metal with copper (by the way, some grades of bronze, in particular beryllium, surpass even high-quality steel in their strength characteristics);
• lower melting point compared to copper;
• good fluidity in the molten state, which makes it possible to successfully use bronze for casting;
• exceptionally high corrosion resistance;
• wear resistance, which is maintained even during long-term use of bronze products under conditions of high friction.

Of course, bronze alloys also have disadvantages. Let us list the most significant of them.

• The not too high ductility of bronze limits the possibility of manufacturing products from it by plastic deformation (rolling, forging, stamping, etc.).
• Bronze, due to some of its characteristics, is poorly processed by cutting.
• Products made of bronze, in particular tools made from it, are difficult to sharpen.

Bronze is used for the manufacture of rubbing and heavily loaded parts that can work in fresh and sea water

By the name of a certain brand of bronze alloy, you can determine which element, other than copper, is included in its chemical composition. Thus, bronze containing tin is called tin, an alloy containing beryllium is beryllium bronze, aluminum is called aluminum bronze, etc.

As mentioned above, the most widespread are tin bronzes, which, due to the fact that bells were made and continue to be made from them, are often called bell bronzes. The classic composition of bronze alloys of this type contains 80% copper (±3%) and 20% tin (also ±3%). To give such bronze improved characteristics, alloying elements can be added to its composition - lead, nickel, arsenic and phosphorus.

Processing temperature and technological features of tin bronzes

Depending on its chemical composition, bronze can be single-component, in which only one additional metal is present, or multicomponent, with several additional elements. Naturally, bronzes, for the manufacture of which several elements were used, are distinguished by improved characteristics.

In the production of multicomponent alloys, a distinction is made between the concepts of primary and secondary bronze. The first type of alloy, often used as a raw material, contains only copper and tin. Primary bronze is used for the production of secondary alloys, for which the necessary alloying elements are added to it.

Bronze alloys (cast alloys are marked with an asterisk)

According to historical data obtained as a result of many archaeological excavations, bronze products began to be used by humans as early as the 4th millennium BC. It is no coincidence that a fairly long period in the development of mankind is called the Bronze Age. Those who today try to make anything from bronze at home are faced with the same problems as ancient man, who made products from it for various purposes.

Production using classical technology

In order to produce a metal such as bronze, it is necessary to melt not only copper, but also an alloying additive in a special container. Such smelting can be performed at home using various heating devices - a muffle or induction furnace, forge, gas burner, etc.

For melting in serial production, induction crucible furnaces (ITFE) are used.

When making a bronze alloy, both in production and at home, one should take into account the fact that when molten copper is mixed with tin, oxides are formed, which significantly worsen the characteristics of the finished alloy.

In order to exclude such a process from the production of bronze, it is necessary to add phosphorous copper to the mixture of molten metals, the amount of phosphorus in which does not exceed 10%.

The use of such an inexpensive deoxidizer as phosphorus copper, the use of which produces gaseous phosphorus anhydrite, although it contributes to the effective removal of non-metallic inclusions from copper, leads to a significant deterioration in such a characteristic of the metal as electrical conductivity.

This can be avoided by using more expensive deoxidizers, which are based on elements such as lithium, calcium and potassium. The surface of molten copper actively interacts with the surrounding air, which leads to intense oxidation of this metal.

To make the oxidation process less intense, crushed charcoal is used to cover the surface of the alloy being created.

It will not be possible to melt bronze for a bell with a gas torch, but for a small figurine or sleeve it is quite possible

Classic bronze production technology consists of the following stages.

• Copper is melted under a layer of flux or charcoal, heating the furnace to a temperature of 1100°.
• For high-quality deoxidation, phosphorous copper is added to the alloy, the amount of which in relation to the mass of the original components should not exceed 10%.
• After the copper is completely melted, tin is added to it if it is necessary to obtain a single-component alloy, or several elements to produce multi-component bronze.
• The resulting alloy, in order to achieve homogeneity of its structure, is heated to a temperature of 1200°.
• To remove harmful impurities from the alloy, which include sulfur, bismuth, manganese, antimony, aluminum, iron, silicon, oxygen and hydrogen compounds, it is refined, which involves oxidizing the main component.
• Improving the mechanical properties of bronze is carried out using an operation such as modification.
• A technological operation such as casting (performed at a temperature of 1300°) allows making a product of the required shape from molten metal.

Bronze, which contains tin in its chemical composition, is more suitable for casting operations. Bronzes of this type, when compared with aluminum alloys, which are not recommended to be heated above a temperature of 1200°, are less easy to cast and are not prone to overheating.

How bronzes are made without tin

To make aluminum-type bronze, you need to consider a number of points. Thus, copper and aluminum, which form the basis of such an alloy, have different densities, which often leads to their delamination in the composition of bronze. That is why foundry production of alloys of this type has the following features.

• Copper, as in the case of tin bronze production, is melted and deoxidized under a layer of flux.
• Additional elements are introduced into the composition of copper, which is in a completely molten state, and then the alloy is thoroughly mixed.
• To improve the properties of future bronze, deoxidizing agents are reintroduced into the alloy.
• After secondary deoxidation, aluminum is added to the molten copper.
• The surface of the molten metal, in order to reduce the intensity of its oxidation when interacting with the surrounding air, is covered with a layer of flux, which can be used as crushed charcoal.
• At the final stage, the alloy is refined with manganese chloride, modified with vanadium, boron or tungsten, and only then poured into pre-prepared casting molds.

Sampling allows you to control the casting process of bronze alloys

The process of producing beryllium bronzes, which are produced using induction furnaces and graphite crucibles, deserves special attention. It should be borne in mind that when smelting bronzes of this type, toxic fumes are released into the surrounding atmosphere, which requires the use of a powerful ventilation system during the production process. Moreover, it is best to cast such bronzes in isolated rooms.

Bronzes containing silicon, like aluminum ones, are produced using charcoal as a flux, and induction furnaces are used for their smelting.

The result of the production of bronze of any type is pigs, the weight of each of them can reach up to 42 kg

All pigs obtained as a result of a separate smelting belong to one batch of the alloy, the total weight of which is not limited. For the entire batch of bronze, which may contain different numbers of pigs, a document is issued that reflects basic information about the presented products:

• trademark of the manufacturer;
• grade of alloy presented in the batch;
• total weight and lot number;
• the number of ingots that make it up;
• results of the chemical analysis of the alloy.

Areas of application of various bronze alloys

Products made from bronze of various grades are actively used in various industries, as well as in everyday life. In particular, the following are made from alloys of this type:

• fittings and parts that are used in direct contact with aggressive media (oil, sea water, high humidity, etc.);
• parts subject to active wear during operation (bearings, liners, rings and other loaded elements of mechanisms);
• shaped parts of pipelines for various purposes.

This is just a small list of areas where products made from various grades of bronze can be successfully used. In fact, their scope of use is much wider.

Source: http://met-all.org/cvetmet-splavy/bronza/bronza-sostav-harakteristiki.html

Extraction of raw materials and bronze manufacturing technologies

The Bronze Age spans approximately the 3rd and 2nd millennium BC. It was at this time that the full metallurgical cycle was developed and implemented: mining, preparation, burning of coal, smelting and refining. Since then, the equipment has changed, they began to use a different method of ore development, but the main stages of the technology have not changed at all.

In this article we will look at the technology for producing, smelting (smelting) bronze, features and methods of producing casting from it in Russia.

An alloy is cast from copper, as well as tin, aluminum, beryllium, lead, and so on. In ancient times, native copper was used for this, but later interest shifted to ores rich in this and other metals.

Today, in addition to native copper, chalcopyrite - copper pyrite, bornite, chalcocite - is of industrial importance. You can use malachite, azurite or cuprite. A mine in which the metal content reaches 0.3–1% is considered promising. Ore is mined mainly by open-pit mining.

Copper is extracted by 3 main methods: pyrometallurgical, hydrometallurgical and electrolytic.

• Pyrometallurgical – the most common, includes several operations. First, copper ore is enriched by flotation or oxidative roasting. The first method is based on the different degrees of wettability between gangue and copper. As a result of enrichment, a concentrate with a metal content of 10–35% is obtained. Oxidative roasting is more suitable for sulfur ores: the mineral is heated twice to a temperature of 700–800 C to anneal the sulfur. The copper matte obtained after enrichment is purged in converters and blister copper with a metal content of up to 91% is obtained. Then the metal is refined by fire cleaning or electrolytic cleaning and pure copper is obtained - 99.9%.
• The hydrometallurgical method involves leaching copper with sulfuric acid to produce a solution of copper and other metals. This method is used in the development of depleted ore.

Tin is the second most popular component of bronze. Obtained from cassiterite, stanine or nigerite. The ore is enriched by mechanical methods, washed to obtain ore concentrate, then subjected to reduction smelting and refining - thermal or electrolytic. Other metals - aluminum, beryllium, lead, are also obtained using appropriate methods.

Bronze has at least 2 components - copper and another metal or non-metal other than nickel and zinc. The alloy can also be multicomponent: such compositions are somewhat more difficult to obtain, but their technical characteristics are more interesting.

This video will tell you how bronze has been produced over the centuries:

Since the composition of different types of bronze is very diverse, a variety of combinations of charge material are used to obtain it. The combinations can be the following:

• only fresh metals, which is quite rare;
• metal and secondary alloys with ligature;
• from circulating alloys;
• only from secondary alloys.

When determining the composition of the charge, the type of furnace, the purity of the components, the degree of burning of the alloy ingredients, and so on are taken into account.

The most common charge composition includes:

• 50–60% fresh metal;
• 20–35% circulating alloys;
• 10–12% scrap if the charge is selected from secondary alloys.

Next, we consider the technologies for manufacturing and casting bronze.

Production technologies

Either pure metals or ready-made alloys in ingots are used as a charge for producing bronze. The first option is less common and is more often used for expensive wrought bronzes. The second one is readily used to produce cast alloys.

Melting based on pigs

Melting using this technology includes 4 stages: melting, overheating, refining and degassing treatment.

An important condition for smelting, regardless of what type of furnace is used, is the minimum duration of the procedure. The shorter the melting time, the lower the risk of saturation of the alloy with gases and the lower the waste of non-ferrous metal.

1. – for this purpose, graphite-chamotte or graphite-carboride crucibles are used. Before use they are dried and calcined.
2. Melting begins with smelting copper, which is loaded in parts or completely. The copper is smelted as quickly as possible under a layer of charcoal. Phosphorous copper is added. The addition of phosphorus provides liquid phosphates, which are much easier to remove from the alloy. After this, tin and other alloy components are introduced into the crucibles, if they are provided for in the recipe.
3. Overheating - the melt heats up to 1150–1200 C. Tin bronze is smelted with a coating of charcoal or coal with salts. If the feedstock is contaminated with silicon, magnesium, or aluminum, liquid salt fluxes are used.
4. Degassing – removal of gas impurities, mainly hydrogen. For this purpose, the melt is purged with dried argon or nitrogen. The procedure time ranges from 3 to 10 minutes depending on the size of the oven.

As a rule, the manufacturing process includes a modification step in order to improve the mechanical properties of bronze. The methods are determined by the composition of the product and its purpose.

Gating systems

Copper alloys create fairly high metallostatic pressure, so bronze casting includes a number of features. Conventional sand molds are not suitable for copper alloys, so molding mixtures with a high clay content are used.

The mold is poured at a temperature of 1100–1200 C. In this case, a metallized burn may appear, which is difficult to remove. The higher the phosphorus content in bronze and the higher the casting temperature, the higher the risk. It is impossible to refuse the addition of phosphorus: the substance increases the fluidity of the alloy, which, in turn, ensures the density of the casting and low shrinkage. So the problem is solved by adding carbon-containing components to the molding mixture - shale resins, for example.

For casting, special equipment is used - gating systems. The choice of process temperature depends on the system design as well as the mass and configuration of the casting.

To ensure high density of castings, a method of directed solidification using refrigerators is used. Rapid cooling reduces the porous zone and increases the thickness of the casting skin.

This video will tell you about melting bronze from brass:

This method is more often used to produce tin bronze castings. The main difference is the use of metal molds for casting - chill mold. This causes a higher solidification rate and, accordingly, a high casting density.

The chill mold is cast from cast iron, the rods are made from steel. Complex cavities are made using shell sand rods. Before pouring, the mold is lubricated with a mixture of machine oil and 6% graphite.

Pouring is carried out into molds preheated to 150–250 C. The castings are removed from the mold as soon as they have acquired sufficient mechanical strength, thus reducing shrinkage stress.

Necessary equipment

As in most non-ferrous metallurgy enterprises, the equipment used to produce bronze depends on many factors: the raw materials used, the characteristics of the smelting, the composition of the finished bronze, the financial capabilities of the enterprises, and so on. Smelting is still a very delicate and highly probable process, and two identical plants can use completely different technologies.

For smelting, a device and furnace power are selected that would ensure the fastest possible melting of copper and other components. There are several options for this.

• Electric furnaces - arc and induction . The latter can be with or without a steel core. Recently, induction crucible furnaces have become more common. In this case, it is easier to prepare the device for a new melt, and the waste in such furnaces does not exceed 0.5–1%.
• Electric arc furnaces with indirect heating - the arc is formed between horizontal graphite electrodes. During melting, the furnace rocks at an ever-increasing angle as the temperature rises. In this way, local overheating of the melt can be avoided.

For casting copper alloy, various types of gating systems are used. Their design is determined by the composition of the alloy, the size and configuration of the casting, and so on.

• The most common device refers to expanding systems with siphon - bottom, and top side inlet. This design is universal and allows you to obtain parts of both simple and complex configurations.
• To obtain blanks with simple configurations, rain or top gating systems are used.
• If castings are produced from alloys that do not form high-strength oxide films, then devices without complex slag traps are used. Otherwise, such a device is necessary.
• If you need to obtain small-sized workpieces, you can use systems with bottom supply.

Next, bronze producers in Russia are considered.

Bronze is a sought-after material of considerable importance for the national economy. It is produced by very well-known enterprises.

• The Kolchuginsky OCM plant offers 20 thousand standard sizes of different types of rolled metal from more than 70 grades of alloys. A significant part of the assortment consists of a variety of bronzes. Today, the plant provides 30% of all rolled non-ferrous metals in the Russian Federation.
• The Kamensk-Ural OCM plant produces products based on 140 different alloys, including zirconium and chrome bronze - heat-resistant alloys.
• Kirov OCM plant has been operating since 1956. This is one of the largest enterprises producing copper and copper alloys of various compositions.
• OJSC Revdinsky Non-Ferrous Metals Processing Plant specializes in the production of pipes and rods made of copper and copper alloys - brass, bronze, cupronickel. The plant has been certified for compliance with the international standard ISO 9002:1994.

World production of copper and copper alloys is determined largely by metal resources. The leaders in the production of refined copper are the USA, Chile and Japan. The USA is also the largest consumer of copper and copper alloys.

Bronze production is a metallurgical process developed in ancient times and still used today. In fact, it was the creation of bronze that served as a model for the development of all other pyrometallurgical processes for producing alloys.

Making a wax model for bronze casting at home is discussed in this video:

Source: http://stroyres.net/metallicheskie/vidyi/tsvetnyie/bronza/syire-i-tehnologii-proizvodstva.html

Melting point of bronze and how to melt and cast at home

Bronze is a copper-based alloy that does not contain nickel and zinc as the main alloying components. Characterized by a relatively high melting point, the metal becomes liquid in the range from +940°C to +1300°C. The most refractory is tin-phosphorus.

Bronze alloys are used to produce long products, sheets and pipes, engine parts, elements of transmission devices, liners for shut-off valves, fittings, taps, souvenirs, instrument parts and much more. You can make casting at home. Bronze is smelted in muffle furnaces or furnaces.

At the melting temperature, bronze becomes thick and does not flow well into the mold; you need to know some tricks in order to do casting yourself.

Main characteristics of bronze alloys

The color of the bronze alloy depends on the quantitative composition of alloying elements. They influence the physical properties: ductility, wear resistance, melting point of bronze.

The alloying components are metals (tin, aluminum, beryllium, lead, manganese) and non-metals (phosphorus, silicon). You can melt any bronze alloy at home. Knowing the markings of the scrap, it is easy to determine the exact melting point of bronze.

But usually the composition of bronze pieces prepared for melting varies. Then the appearance of the metal is assessed.

Bronze alloys are classified into two categories:

1. tin ones are more ductile;
2. tinless ones are less easy to process:

• beryllium are characterized by high strength, maximum tensile strength and torsion;
• aluminum has a low melting point, is resistant to corrosion, and has good anti-friction properties;
• lead plastic, easy to machine;
• with additives of zinc and silicon, they are characterized by fluidity; when melted, they evenly fill the casting mold;
• the alloy with iron can be welded well, but its contact with aggressive environments is undesirable;
• manganese improves strength characteristics while maintaining the ductility characteristic of copper;
• Tin-lead bronzes are malleable, they are subjected to hot deformation, and the alloy is made into hot-rolled products.

For industrial casting, tin bronze with a low melting point, up to +1000°C is used.

Unlike brass, bronze is more viscous at its melting point. When filling forms of complex configurations in production shops, centrifuges are used. The alloy, heated above the melting point by 5°, is given additional acceleration so that it spreads evenly.

When making handicraft castings, it is advisable to take into account the viscosity of the bronze alloy at the melting point so that there is no defect on the surface. Foundry workers consider low shrinkage during cooling to be an advantage of non-ferrous metal. It is possible to obtain castings that do not require lengthy finishing to the specified geometric dimensions.

High-quality shaped castings are made from bronze alloys.

Is it possible to melt and cast bronze at home?

It is impossible to recreate industrial technology using a homemade method. The metal is overheated to improve fluidity. At a temperature above the melting point, a certain time interval is maintained, only after this the melt is poured into molds. Technologists calculate the temperature regime for each alloy.

Source: https://svarkaprosto.ru/tehnologii/temperatura-plavleniya-bronzy

How to melt bronze at home? — Machine tools, welding, metalworking

Many people today are trying to master industrial production technologies at home. Provided that the sequence of certain manipulations is followed and the necessary equipment is available, it is sometimes possible to solve very complex problems.

For example, you can easily melt metals and create bladed weapons or exclusive jewelry with your own hands. To do this, you need to know to what temperature the metal needs to be heated and how best to do it.

This article will tell you what the melting point of bronze is, what you need to take into account if you want to subjugate this metal.

What is bronze? This is an alloy consisting of a main component (copper) and an additional alloying element.

Depending on what acts as an alloying additive, several grades of the material being described are distinguished, therefore each type of bronze has its own melting point.

The physical and chemical properties of bronze depend on the percentage of additional components. Its marking helps to understand what impurities are contained in the alloy.

All bronze compositions can be divided into two large groups:

Tin alloys are a type of bronze that contains tin as an alloying element. This metal is stronger than copper, but it is fusible. The combination of copper (80%) and tin (20%) is the first alloy that humanity has learned to create. With its help, church bells were cast in Rus'. The metal sounded good, but was fragile. Therefore, there was a need to look for more advanced alloys.

Tin-free alloys do not contain brittle tin. Beryllium, silicon, lead and aluminum can be used as alloying additives. Depending on which of the listed metals is combined with copper, the alloy acquires its physical and chemical properties.

For example, beryllium makes it possible to create alloys whose strength characteristics are much superior to high-quality steel. The addition of silicon makes bronze more resistant to mechanical friction.

Lead helps to form high resistance to corrosion, aluminum improves the friction characteristics of the alloy.

The process of melting bronze must begin with studying its composition. All tin grades melt at a temperature of 900–950°C, tin-free grades melt at a temperature of 950–1080°C.

Note! When casting, another indicator of the alloy is taken into account - its viscosity. Tin bronze has a higher temperature than brass, so when heating it it must be very overheated. Then, after cooling, the described brand gives minimal shrinkage, so this type of bronze is ideal for shaped casting.

Is it possible to cast bronze at home?

Many of us wonder whether the process of melting the described alloy is possible at home. It is impossible to recreate industrial casting. Since bronze has a high melting point, special conditions are required to work with hot metal.

You can try to master small casting, which allows you to create jewelry or small crafts. To carry out this process, you will have to allocate a separate room, as well as take all fire safety measures and provide high-quality ventilation.

Large bronze parts can be made where there is an earthen or concrete floor (this could be a garage with good forced ventilation).

To work you will need certain equipment and special tools. Only a muffle furnace will allow casting (the presence of a thermostat will greatly simplify the solution of the task). For large pours, you will have to install a forge. You can melt metal in a cast iron container that is shaped like a spout. It helps to gently pour the molten metal into the mold. This cast iron container is called a crucible.

The crucible is removed from the furnace using long tongs and a special hook. There should be a casting mold at hand. Charcoal is best suited for lighting a muffle furnace, and coke for a forge.