Is bronze magnetic? — Metals, equipment, instructions
If identifying pure copper from its alloys is a quite feasible task at home, then it is quite difficult to discern the differences between brass and bronze. The main reason for this is the existence of many brands of these compounds.
For example, brass is an alloy of copper with zinc as the base alloying component. But the Zn content in the compound varies over a wide range of values: 4 – 45%.
Naturally, high-copper brass grade L96 will differ significantly from L59-1.
Brass washers brand L96
Bushings made of tin-free bronze, brand BrA9Zh3
As can be seen from the top 2 photographs with images of parts made of brass and bronze, it is practically impossible to distinguish these 2 metals (alloys) visually; perhaps only a specialist who has worked all his life with these copper alloys can do this.
The only sure way to determine the type of connection remains spectral analysis, using an analyzer that helps distinguish between different metals and alloys. The methods presented below for distinguishing bronze from brass at home should be taken quite carefully . Remember! None of the methods gives a guaranteed result.
See similar articles:
Visual approach
Alloys with a high content of the main alloying component are easily recognizable by color. The technique for visually distinguishing brass from bronze is as follows:
- Brass is an alloy with a high zinc content. This causes the color of the compound to shift from the pink-red hue of pure copper to golden yellow tones. We can confidently say that the color of brass is closer to gold. Although scrap brass comes in different forms and different states, and it’s certainly not easy to identify with your eyes, the same applies to scrap bronze.
- Bronze. The quantitative content of tin in the alloy determines the color of the compound. Bronze with a maximum Sn content of 33% is characterized by a silvery-white color. The alloy, containing at least 90% copper, also borrows its color - closer to brown-red tones.
Since in practice, compounds with a high tin content are rare, you can trust the following rule. Brass is a golden-yellow hue, bronze is reddish.
Pure physics
The density of copper alloys is the next criterion for distinguishing brass from bronze. However, the popular belief that scales will give a definite answer is incorrect. Confirmation of this is provided by connection densities:
- rolled brass – 8.4 – 8.7;
- yellow brass – 8.43;
- bronze – 7.4 – 8.9.
All values are given in g/cc. As you can see, the weight of bronze, like its color, is highly dependent on the tin content. When its inclusion is at the level of 8%, the connection density is minimal and lower than that of brass. An increase in tin content leads to a heavier alloy. The result is that such bronze weighs more than brass. Therefore, using mass as a distinguishing criterion for copper alloys is not recommended in practice.
This video outlines the principle of calculating and determining metal based on weight and density:
How to distinguish brass from bronze with a magnet
There is no limit to human misconceptions. Most ordinary people are confident that a magnet is able to give a definite answer. To verify whether this is so, let us return to the chemical composition of the alloys. Of the main components of the compounds: copper, tin, zinc, aluminum, iron and nickel, only the last pair is magnetic. As a result, only grades of alloys containing Fe and Ni are capable of being attracted to a magnet. These are BrAZh bronzes, for example.
The alloy BrAZhN-10-4-4 has the greatest magnetic susceptibility, where the total proportion of iron and nickel is 7 – 11%. However, to get a noticeable effect you will need a powerful magnet, for example neodymium. Among brasses, grades containing iron or nickel are LAZH and LAN, respectively. The proportion of magnetic metals in them is 1–3%, which complicates identification even with neodymium.
However, the weak magnetic properties of some grades of copper alloys lead to rumors that this is an effective way to distinguish brass from bronze.
So, you should know that you CANNOT distinguish brass from bronze with a MAGNET!
— Brass and its magnetic properties:
Heat treatment
Temperature 600-650 °C is critical for zinc. The metal oxidizes when heated this way. This is a real way to visually distinguish bronze from brass in a burner flame:
- Bronze. The alloy will simply heat up. Its color and mechanical properties will remain unchanged. Attempting to bend a bronze specimen may result in its destruction.
- Brass. Oxidation of zinc causes an ashy coating on the surface of the joint. Additionally, after heat treatment at 600 °C, brass becomes ductile, and the alloy sample does not break when bent.
All that remains is to find a powerful burner. Here a gas stove or a lighter flame will not be enough.
— Melting bronze and brass:
Chemical technique
The use of reagents is an effective but destructive way to distinguish between copper alloys. Chemical analysis takes place in several stages:
- The shavings are removed from brass and bronze.
- An aqueous nitric acid solution is prepared with a 1:1 ratio.
- The shavings are placed in various containers filled with an acid reagent.
- Each tank is heated to a boil after the chips have completely dissolved.
- The compositions are kept in a boiling state over low heat for 30 minutes.
The result is that the container with brass remains transparent, while a white tin precipitate forms in the bronze container. Naturally, the technology is not suitable for tin-free alloys.
Welding machine
What is the best way to distinguish bronze from brass? It is necessary to catch the arc with an electrode at the edge of the blank. Bronze has a smokeless process. On the contrary, exposing a brass blank to a welding arc will cause the zinc to burn out. The process is accompanied by the appearance of white smoke.
Spectral analysis is the only way with guaranteed results
The diversity of the chemical composition of copper alloys makes it difficult to accurately identify the type of connection. Each of the proposed methods for distinguishing brass and bronze does not provide a 100% guarantee. Therefore, if you need to get an accurate answer, it is better to contact a scrap metal collection point that has a spectral laboratory.
Source: https://spb-metalloobrabotka.com/magnititsya-li-bronza/
How to distinguish copper from other metals
For most of us, knowledge about copper and its properties is limited to a school chemistry course, which is quite enough at the everyday level.
However, sometimes there is a need to reliably determine whether a material is a pure element, an alloy, or even a composite material.
The opinion that this information is needed only by those who are engaged in the acceptance or delivery of scrap metal is erroneous: for example, on amateur radio forums, topics are often raised about how to distinguish copper in wires from copper-plated aluminum.
Briefly about element No. 29
Pure copper (Cu) is a golden-pink metal with high ductility, thermal and electrical conductivity. Chemical inertness in an ordinary non-aggressive environment is ensured by a thin oxide film, which gives the metal an intense reddish tint.
The main difference between copper and other metals is color . In fact, there are not so many colored metals: only gold, cesium and osmium are similar in appearance, and all elements included in the group of non-ferrous metals (iron, tin, lead, aluminum, zinc, magnesium and nickel) have a gray color with varying intensity of shine.
An absolute guarantee of the chemical composition of any material can be obtained only through spectral analysis. The equipment for carrying it out is very expensive, and even many expert laboratories can only dream of it. However, there are many ways to distinguish copper at home with a high degree of probability.
1. Determination by color
So, we have before us a piece of unknown material that needs to be identified as copper. The emphasis on the term “material” rather than “metal” was made specifically, since recently many composites have appeared that are very similar to metals in appearance and tactile sensations.
First of all, we consider color. It is advisable to do this in daylight or “warm” LED lighting (under “cool” LEDs, the reddish tint changes to yellow-green). It is ideal if there is a copper plate or wire for comparison - in this case, errors in color perception are practically eliminated.
Important: old copper products can be covered with an oxidized layer (a greenish-blue loose coating): in this case, the color of the metal must be looked at in a cut or saw cut.
2. Determination by magnet
Color matching is a reliable but not sufficient method of identification. The second step of independent experiments will be a test with a magnet. Chemically pure copper is classified as diamagnetic - i.e. to substances that do not respond to magnetic influence.
If the material under study is attracted to a magnet, then it is an alloy in which the content of the main substance is no more than 50%.
However, even if the sample did not react to the magnet, it is too early to rejoice, since often an aluminum base is hidden under the copper coating, which is also not magnetic (this can be eliminated by filing or cutting).
3. Determination by reaction to flame
Another way to identify copper is to heat a sample over an open fire (gas stove, lighter or regular match). When heated, copper wire will first lose its shine and then turn black-brown, covered with oxide. This method can also be used to cut off composite materials that, when heated, begin to smoke and form a gas with a pungent odor.
4. Determination through chemical experiments
The reaction with concentrated nitric acid is indicative: if the latter is dropped onto the surface of a copper product, a green-blue color will occur.
A qualitative reaction to copper is dissolution in hydrochloric acid followed by exposure to ammonia. If a copper sample is left in an HCl solution until completely or partially dissolved, and then ordinary pharmaceutical ammonia is dropped into it, the solution will turn intensely blue.
Important: working with chemicals requires precautions. Independent experiments should be carried out in a well-ventilated area using personal protective equipment (rubber gloves, apron, goggles).
How to distinguish between copper and its alloys?
Copper alloys are widely used in industry. Over many years of research, it has been possible to obtain many materials with unique properties: high ductility, electrical conductivity, chemical resistance, strength (all depends on alloying additives). The most common are bronze (with the addition of tin, aluminum, silicon, manganese, lead and beryllium), brass (with the addition of 10-45% zinc), as well as copper-nickel alloys (nickel silver, cupronickel, copel, manganin).
Only bronze and brass are difficult to identify, since copper-nickel alloys differ significantly in color due to their low copper content.
Copper or brass?
Brass can contain from 10 to 45% zinc, a silver-gray metal. Naturally, the more zinc, the paler the alloy. However, high-copper brasses, in which the amount of additives does not exceed 10%, differ little in color from the copper sample.
In this case, you can only trust your feelings: brass is much harder and more difficult to bend (for greater reliability, a comparison with a reference sample is advisable). You can try to remove the shavings: copper shavings will have a curl shape, brass shavings will be straight, needle-shaped.
When the samples are placed in a solution of hydrochloric acid, no reaction with copper is observed, and a white coating of zinc chloride forms on the surface of the brass.
Copper or bronze?
Like brass, bronze is much stronger, which is explained by the presence of harder metals in the alloy. The most reliable test will be a “tooth test” - there is unlikely to be a trace of pressure left on the surface of the bronze.
You can also experiment with a hot saline solution (200 g of table salt per 1 liter of water). After 10-15 minutes, a copper sample will acquire a more intense shade than a bronze one.
For those familiar with electrical engineering
Very often, copper cores from electrical cables are sold as scrap non-ferrous metals, and there are often cases when copper-coated aluminum is used in the production of electrical products. This material has a significantly lower density, but due to its irregular geometric shape, determining the volume to calculate the density is quite difficult.
In this case, copper can be determined by electrical resistance (of course, if you have the appropriate instruments - a voltmeter, ammeter, rheostat). We measure the cross-section and length of the core, take instrument readings, and Ohm’s law will help you.
Resistivity is a fairly accurate characteristic by which any metal can be identified with a high degree of reliability.
Conclusion
It is possible to accurately determine the quality of copper scrap or the content of the main substance in the alloy only after an examination: all of the above methods are approximate. If we consider pricing when purchasing scrap metal, the most expensive is electrical copper, the cheapest are alloys of the brass group. The final cost of the transaction can be clarified with the managers of companies involved in the purchase of scrap non-ferrous metals.
Source: https://blog.blizkolom.ru/kak-otlichit-med
How to distinguish between brass and bronze - proven methods
If identifying pure copper from its alloys is a quite feasible task at home, then it is quite difficult to discern the differences between brass and bronze. The main reason for this is the existence of many brands of these compounds.
For example, brass is an alloy of copper with zinc as the base alloying component. But the Zn content in the compound varies over a wide range of values: 4 – 45%.
Naturally, high-copper brass grade L96 will differ significantly from L59-1.
Brass washers brand L96
The situation with bronze is even more complicated. This is an alloy based on tin, as well as other elements, including non-metallic ones (difficult to distinguish from brass). Alternatively, there is tin-free bronze. In such compounds, the main alloying additives are aluminum, beryllium, manganese, silicon or magnesium. The result is that the existence of significant differences in the chemical composition of metal alloys makes it difficult to identify even brasses or bronzes with each other.
Bushings made of tin-free bronze, brand BrA9Zh3
As can be seen from the top 2 photographs with images of parts made of brass and bronze, it is practically impossible to distinguish these 2 metals (alloys) visually; perhaps only a specialist who has worked all his life with these copper alloys can do this.
The only sure way to determine the type of connection remains spectral analysis, using an analyzer that helps distinguish between different metals and alloys. The methods presented below for distinguishing bronze from brass at home should be taken quite carefully . Remember! None of the methods gives a guaranteed result.
See similar articles:
What metals are not magnetic and why?
Any child knows that metals are attracted to magnets. After all, they have more than once hung magnets on the metal door of the refrigerator or letters with magnets on a special board. However, if you put a spoon against a magnet, there will be no attraction. But the spoon is also metal, so why does this happen? So, let's find out which metals are not magnetic.
Scientific point of view
To determine which metals are not magnetic, you need to find out how all metals in general can relate to magnets and a magnetic field. With respect to the applied magnetic field, all substances are divided into diamagnetic, paramagnetic and ferromagnetic.
Each atom consists of a positively charged nucleus and negatively charged electrons. They move continuously, which creates a magnetic field. The magnetic fields of electrons in one atom can enhance or cancel each other, depending on the direction of their movement. Moreover, the following can be compensated:
- Magnetic moments caused by the movement of electrons relative to the nucleus are orbital.
- Magnetic moments caused by the rotation of electrons around their axis are spin moments.
If all magnetic moments are equal to zero, the substance is classified as diamagnetic. If only spin moments are compensated - to paramagnets. If the fields are not compensated, use ferromagnets.
Paramagnets and ferromagnets
Let's consider the option when each atom of a substance has its own magnetic field. These fields are multidirectional and compensate each other. If you place a magnet next to such a substance, the fields will be oriented in one direction. The substance will have a magnetic field, a positive and a negative pole.
Then the substance will be attracted to the magnet and can itself become magnetized, that is, it will attract other metal objects. For example, you can magnetize steel clips at home. Each one will have a negative and a positive pole, and you can even hang a whole chain of paper clips on a magnet.
Such substances are called paramagnetic.
Ferromagnets are a small group of substances that are attracted to magnets and are easily magnetized even in a weak field.
Diamagnets
In diamagnetic materials, the magnetic fields inside each atom are compensated. In this case, when a substance is introduced into a magnetic field, the movement of electrons under the influence of the field will be added to the natural movement of electrons. This movement of electrons will cause an additional current, the magnetic field of which will be directed against the external field. Therefore, the diamagnetic material will be weakly repelled from the nearby magnet.
So, if we approach the question from a scientific point of view, which metals are not magnetic, the answer will be – diamagnetic.
Distribution of paramagnets and diamagnets in the periodic table of Mendeleev elements
The magnetic properties of simple substances change periodically with increasing atomic number of the element.
Substances that are not attracted to magnets (diamagnets) are located mainly in short periods - 1, 2, 3. Which metals are not magnetic? These are lithium and beryllium, and sodium, magnesium and aluminum are already classified as paramagnetic.
Substances that are attracted to magnets (paramagnets) are located mainly in the long periods of the Mendeleev periodic system - 4, 5, 6, 7.
However, the last 8 elements in each long period are also diamagnetic.
In addition, three elements are distinguished - carbon, oxygen and tin, the magnetic properties of which are different for different allotropic modifications.
In addition, there are 25 more chemical elements whose magnetic properties could not be established due to their radioactivity and rapid decay or the complexity of synthesis.
The magnetic properties of lanthanides and actinides (all of which are metals) change irregularly. Among them there are para- and diamagnetic materials.
There are special magnetically ordered substances - chromium, manganese, iron, cobalt, nickel, the properties of which change irregularly.
What metals are not magnetic: list
There are only 9 ferromagnets, that is, metals that are highly magnetic, in nature. These are iron, cobalt, nickel, their alloys and compounds, as well as six lanthanide metals: gadolinium, terbium, dysprosium, holmium, erbium and thulium.
Metals that are attracted only to very strong magnets (paramagnetic): aluminum, copper, platinum, uranium.
Since in everyday life there are no such large magnets that would attract a paramagnetic material, and also no lanthanide metals are found, we can safely say that all metals except iron, cobalt, nickel and their alloys will not be attracted to magnets.
So, what metals are not magnetic to a magnet:
- paramagnetic materials: aluminum, platinum, chromium, magnesium, tungsten;
- diamagnetic materials: copper, gold, silver, zinc, mercury, cadmium, zirconium.
In general, we can say that ferrous metals are attracted to a magnet, non-ferrous metals are not.
If we talk about alloys, then iron alloys are magnetic. These primarily include steel and cast iron. Precious coins can also be attracted to a magnet, since they are not made of pure non-ferrous metal, but of an alloy that may contain a small amount of ferromagnetic material. But jewelry made of pure non-ferrous metal will not be attracted to a magnet.
What metals do not rust and are not magnetic? These are ordinary food grade stainless steel, gold and silver items.
Source: https://News4Auto.ru/kakie-metally-ne-magnitiatsia-i-pochemy/
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.
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
7 Ways to Tell Copper from Brass
To accurately distinguish brass from copper at home, it is enough to know the composition and some characteristics of these materials.
Copper is a pure metal, and its alloy with zinc is called brass. Due to their different compositions, these materials have several important differences:
- Color . Copper has a reddish tint, while brass is yellow.
- Weight . Copper is slightly heavier than brass.
- Hardness _ Copper is softer, brass is harder.
- Density _ For copper it is 8920 kg/m3, for brass it is from 8300 to 8700 kg/m3.
It should be noted right away that it is not possible to recognize at home that what we have in front of us is a metal or its alloy using a magnet. Both materials are not attracted to them.
However, there are several ways to distinguish copper from brass without resorting to spectral analysis in the laboratory. All of them are described below - from the simplest to the most complex.
1. Contact a specialist
The easiest way to identify metal is to show it to a specialist with a trained eye. This task can be easily handled by a person working in metallurgy - a foundry worker, and so on. The difference between copper and brass can also be determined by a jeweler, a pawnshop worker, a chemistry teacher, or an experienced scrap metal acceptor.
2. Determination by color
The easiest way to determine whether a product is copper or brass is by its color. For accuracy, it is recommended to thoroughly clean the metal surface from dirt and oxide film. As mentioned earlier, copper has a reddish tint, sometimes brownish or pink.
If the product under study has a yellowish color, reminiscent of gold, then this is most likely brass. And the more pronounced the yellowness, the greater the proportion of zinc in the alloy.
You can determine the metal by color by comparison with a known product. In everyday life, as a copper sample, you can use an electrical wire, cleared of insulation and protective varnish. Brass can be seen on the plugs of electrical appliances - their pins are made from this alloy.
3. Identification by sound
This method is only suitable for large items. If you hit a copper product with any metal tool, you will hear a muffled low-frequency sound. When performing similar actions with a brass object, the sound turns out to be more ringing and high-frequency.
This feature occurs because copper is slightly denser and heavier than its alloy with zinc. The described method is not suitable for small objects.
4. Determination by hardness
If the product is thin-walled, then the composition can sometimes be determined by its compliance with mechanical loads. So, copper bends much easier, but it does not crack or break. Brass is a harder and more brittle material, so a product made from it is easier to break.
This method is not suitable for thick-walled or monolithic products, since they cannot be bent.
5. Determination using chemistry
This method is one of the simplest and most accessible, and at the same time quite accurate. To determine the composition of the metal, you will need a solution of hydrochloric acid. Such liquids are often used to clean contacts when soldering in radio electronics. Accordingly, acid can be bought at any radio store. And it's inexpensive.
Without going into details and without resorting to chemical formulas, the essence of the test is as follows. A few drops of acid must be applied to the surface of the metal being tested. If it is copper, then it will simply be cleaned and acquire its natural reddish or pinkish tint. If we have brass in front of us, then a chemical reaction will take place on its surface with the release of a white substance - zinc oxide.
6. Determination by drilling
If the product is scrapped, that is, it would not be a pity to damage it, then its composition can be determined using an ordinary drill and a thin metal drill. When processing copper, due to its softness and ductility, long curling chips will come out from under the drill.
In the case of drilling brass, you will see how the metal crumbles and the chips have sharp corners. Its length, however, will be small.
7. Determination by density
This is the most complex method described, and rarely anyone adopts it. However, it is quite effective and accurate, and most importantly, it can be performed at home.
The bottom line is that first the exact mass of the product under study is determined, and then its volume. Knowing the density of copper and brass, using the identified parameters it will be possible to determine the composition of the material. If an object has a complex shape, then its volume can be calculated by immersing it in a container of water. To determine weight, it is better to use scales with high accuracy.
Source: http://metallomcity.ru/stati-o-metallolome/otlichit-med-ot-latuni
How to distinguish bronze from brass at home?
There are a number of ways that will tell you how to distinguish bronze from brass. In the presented material I would like to consider the simplest and most accessible solutions for implementing this task. Let's find out how to distinguish bronze from brass at home.
What is bronze?
Before we figure out how to distinguish bronze from brass, let's find out what each alloy is. Let's start with bronze. So, bronze is an alloy of tin and copper, with admixtures of silicon, aluminum, beryllium and lead. It is the quality of the tin used that largely determines the nature of the future alloy.
There is a special type of bronze, in the manufacture of which tin is replaced with nickel or zinc. This alloy is known as spiatr. Essentially, the material is a cheap version of bronze, which is not of the best quality.
According to the above manufacturing principles, bronze is divided into tin and tin-free. At the beginning of the last century, metallurgists produced arsenic bronze. However, due to its high toxicity, the material was never widely used.
What is brass?
Brass is practically the same alloy as bronze. But instead of the alloying composition in the form of tin, zinc is used here in combination with copper. Sometimes lead, iron, nickel, manganese, and other elements are added to the alloy.
The ancient Romans knew how to produce brass. They were the first to learn how to combine molten copper with zinc ore. Pure zinc began to be used for the production of brass only at the end of the 18th century in Britain. The British often used the alloy to create fake gold, because brass, like a noble metal, has an attractive sunny shine.
Today the material is widely used to create the so-called bimetal - an alloy where steel is combined with brass. This solution contributes to the production of metal that is resistant to corrosion and abrasion. At the same time, bimetal products have good ductility.
Defining Differences Between Bronze and Brass
How to distinguish bronze from brass? The difference between the presented alloys is as follows:
- Brass is produced by combining zinc with copper. In turn, bronze is produced by alloying copper with tin.
- Bronze can be in contact with sea and salt water for a long time without destroying the structure of the material. Brass requires additional processing in the form of alloying.
- Bronze has increased resistance to mechanical wear and is a durable material. For this reason, the alloy is widely used to create all kinds of sculptures and monuments. Brass is not suitable for these purposes, although it is used as elements of artistic products.
- How to distinguish copper from brass and bronze? Copper has a reddish tint. At the same time, bronze has a dark brown color and a coarse-grained structure. Brass has a yellow tint and is a fine-grained material.
Differences between bronze and brass according to weight
How to distinguish bronze from brass based on the weight of the materials? It is worth noting that bronze is a fairly heavy alloy. In equal volumes of workpieces, bronze will be clearly heavier than brass. Therefore, you can distinguish products from individual alloys by weighing them on your palms.
You need to try to distinguish between materials using the thermal effect method. However, the results in this case will be more reliable. What do we have to do? It is necessary to heat both alloys using a gas burner to a temperature of more than 600°C. With this exposure, an ashen-colored coating forms on the surface of the brass product, which is zinc oxide. At the same time, the bronze will remain in its original form.
After heating, the brass will become more ductile. Bronze does not change its physical properties when exposed to high temperatures. If you try to bend a brass workpiece, the structure of the latter will not be damaged. As for bronze, it will definitely break at the bend.
How to distinguish brass from bronze with a magnet?
As noted above, bronze contains tin and lead. These materials can be attracted by a magnet. The only thing required to carry out the experiment is to find a fairly strong magnet. When using it, the bronze will slightly stick to the surface. The magnet will not have any effect on brass.
Finally
As you can see, there are a number of ways that allow you to distinguish bronze from brass at home. In most cases, there are pronounced visual differences between products made from these alloys. Therefore, to cope with the task, sometimes it is enough just to carefully consider both materials.
Source: https://FB.ru/article/286414/kak-otlichit-bronzu-ot-latuni-v-domashnih-usloviyah
Is brass magnetic or not, alloy composition, use
Collectors and numismatists often wonder: is brass magnetic or not? The fact is that this alloy is often used in the manufacture of coins. But it is quite difficult to evaluate found specimens using a magnet, because not all brass is magnetic.
- What kind of alloy is this?
- Nickel brass
- Tips and warnings
What kind of alloy is this?
Brass alloys and compounds like them have been used for coinage since ancient Roman times. The material was also popular in China, Bulgaria and the German Democratic Republic.
Brass
Brass is diamagnetic - alloys that are pushed out of a magnetic field. It is created on the basis of copper (56-67%) with the addition of zinc. The following can also be used as a ligature:
- iron;
- nickel;
- manganese;
- lead.
Brass should not be confused with other copper-zinc alloys. Only a compound with the above proportions of base metals is considered brass. If the ratio of alloying and base components is different, the alloy is called copper-zinc, not brass. For example, a similar connection was used to mint Soviet coins in denominations of 1, 3 and 5 kopecks from 1961 to 1991.
Brass containing iron (LAZhMts, LZhMts) or nickel (LAN) has weakly pronounced magnetic properties. However, to test these properties, a powerful neodymium magnet is required, and even its use does not guarantee an accurate result. The proportion of alloying components often does not exceed 1-3%, which greatly complicates this method of identification.
If the brass does not contain a ferromagnetic alloy, it will not be magnetic: neither copper nor zinc have such properties. However, a brass coin can still react to a magnet - in exceptional cases:
- If a ferromagnet got into the alloy not as an alloying component, but by mistake. Such exclusive specimens were discovered among coins of the Soviet period. Currently, they are valued significantly higher than their analogues.
- If the "brass" coin is actually made of a cheaper alloy with the outer plate brazed. This combination is used to reduce the cost of issuing monetary units. In this case, the basis of the product is stainless steel or its analogue, to which the magnet reacts.
Other copper-based alloys that are not brass may also have magnetic properties. This characteristic depends on whether ferrous metals have been added to their composition.
Nickel brass
Nickel-containing brass (NBR) was developed for electrical connectors, as a replacement for expensive silver plating. It is resistant to corrosion, abrasion, and has low transient resistance. The alloy has increased mechanical properties, but is well processed by pressure in cold and hot states.
Nickel brass is used for the minting of modern coins in many countries. In addition, the main areas of its application include the production of:
- pressure tubes;
- condenser tubes for legal proceedings;
- meshes for papermaking machines.
Externally, nickel brass can be confused with ferrous bronze (BRAZH). It is these two alloys that are usually tried to be distinguished by magnetic testing. This method has no scientific justification, since the magnetic properties do not depend on the basic components of the alloy (copper with zinc for brass or copper with tin for bronze), but on alloying additives (nickel, iron) and their proportions. The ligature varies depending on the specific brand.
Tips and warnings
Experienced specialists distinguish nickel brass from ferrous bronze by the color of the chips in direct sunlight: brass will have a greenish tint, bronze will have a yellowish-reddish tint. An even more accurate result is obtained by spectral analysis of chemical compounds. Everything else is myths and speculation.
Source: https://DedAntikvar.com/interesnoe/obladaet-li-latun-magnitnymi-svojstvami
Magnetic properties and rules for cleaning brass
Very often it becomes necessary to determine what alloy a particular product is made of. This is especially important for numismatists when it comes to evaluating coins. Precious metals have not been used for minting coins for a long time. Nowadays, copper-based alloys are often used to reduce the cost of production. To use a magnet to figure out whether a coin is made of brass, you need to know whether brass is magnetic or not.
How to clean brass coins?
Like any other coin in numismatics, they need to be stored very carefully. Coins made from brass often show clouding, darkening, black, green or blue spots. All these are traces of external influences that need to be gotten rid of in order for the product to acquire its original appearance. How to clean brass products?
One of the most common cleaning methods is electrolysis. However, it is worth cautioning that a common side effect of using this cleaning on a copper-zinc alloy is a change in the color of the coin and the appearance of a copper tint.
Particular attention should be paid to fixing the coin during cleaning, since if it touches the electrode, a short circuit may occur and the coin may become chipped. You can use a soda solution as an electrolyte, and a car battery will serve as the current source. The coin is attached to the negative charge, and a stainless steel electrode is attached to the positive charge.
In five minutes, the coin is completely cleaned; you can then wipe it with a soda-based cleaning agent, but strong mechanical impact is not recommended.
Ammonia dissolves oxides and traces of corrosion on copper-zinc coins well. You just need to know that it is often used not only for cleaning coins containing copper, but also for patination. So after removing the coin from the solution, you should rinse it thoroughly.
Trilon B can also be used to clean brass coins. This solution removes all oxides and does not interact with the alloy from which the coin is made. Even if a coin is left in a solution of this substance for a long time, its color will not change and it will not be destroyed in any way. If the oxides stick quite firmly to the surface of the coin, then instead of significantly increasing the exposure time, you can simply warm up the solution a little.
The abrasive cleaning method is not suitable for coins that will be sold and have a high value. However, to add shine to a modern coin in a collection, it will do the job. For this, it is best to use GOI paste. Polishing can be done with a portable engraver. One more thing about this method: it cannot be used to clean coins with fine design details.
It's not common to find coins or other collectibles made of brass these days. But if they still have magnetic properties, this does not mean that they are made of any other alloy, although this may indicate surface application. Brass is not magnetic if there is little or no nickel or iron in its composition.
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Source: https://DedPodaril.com/lityo/latun-magnititsya-ili-net.html
Is brass magnetic? - Metalist's Handbook
To accurately distinguish brass from copper at home, it is enough to know the composition and some characteristics of these materials.
Copper is a pure metal, and its alloy with zinc is called brass. Due to their different compositions, these materials have several important differences:
- Color . Copper has a reddish tint, while brass is yellow.
- Weight . Copper is slightly heavier than brass.
- Hardness _ Copper is softer, brass is harder.
- Density _ For copper it is 8920 kg/m3, for brass it is from 8300 to 8700 kg/m3.
It should be noted right away that it is not possible to recognize at home that what we have in front of us is a metal or its alloy using a magnet. Both materials are not attracted to them.
However, there are several ways to distinguish copper from brass without resorting to spectral analysis in the laboratory. All of them are described below - from the simplest to the most complex.
Is brass magnetic or not?
Denis87 (27 August 2014 — 22:04) wrote:
Tell me, what kind of brass is this that is magnetic? I began to process a workpiece from the tips of high-voltage wires from cars
Most likely, low-quality brass, metal remelting, “bolts with the letter G..”, defective material in general. Think for yourself, iron increases resistance, but here are the contacts. There was a case, you bought a cable, so it had a PVA braid, was it magnetic?
Denis87 (27 August 2014 — 22:44) wrote:
They make whatever they come across.
Lampyris (28 August 2014 — 00:07) wrote:
You can try scraping it with a lathe cutter. Brass usually produces shavings, while bronze crumbles.
No way. Try crumbling BrAZh. Among turners, brass is divided into loose (l59) and toffee (l63).
Metalbreaker (28 August 2014 - 10:03) wrote:
In general, brass can be distinguished from bronze by the color of the chips. You need to look at the sunlight, brass will give a greenish tint, and bronze will give a yellowish-reddish tint.
You won't be able to tell anything apart. As a foundry friend I know said, the line between brass and bronze is very blurred.
How to distinguish bronze from brass at home?
There are a number of ways that will tell you how to distinguish bronze from brass. In the presented material I would like to consider the simplest and most accessible solutions for implementing this task. Let's find out how to distinguish bronze from brass at home.
How to distinguish alloys by heating?
You need to try to distinguish between materials using the thermal effect method. However, the results in this case will be more reliable. What do we have to do? It is necessary to heat both alloys using a gas burner to a temperature of more than 600 o C. With this exposure, an ashen coating forms on the surface of the brass product, which is zinc oxide. At the same time, the bronze will remain in its original form.
After heating, the brass will become more ductile. Bronze does not change its physical properties when exposed to high temperatures. If you try to bend a brass workpiece, the structure of the latter will not be damaged. As for bronze, it will definitely break at the bend.
Magnetic test for bronze
Scrap bronze can be identified using a magnet due to its non-magnetic properties. Bronze is a non-magnetic alloy of tin and copper. Due to its non-magnetic properties, the presence of bronze can be determined by magnetic attraction testing. Metals with magnetic properties have an ordered electron structure. Bronze is made up of metals that are not magnetic in nature. For identification you will need a horseshoe magnet, an iron nail, bronze.
- Lay out all the scrap metal pieces on a flat surface.
- Pass a magnet over them. If the piece of metal is large, the magnet will be attracted down; if it is small, then it will be attracted to the magnet.
- Write down your observations about what you saw. Note that different pieces of metal have different strengths of attraction.
- Separate the scrap pieces into magnetic and non-magnetic. The bronze will be in the non-magnetic part.
- Assess the possible presence of bronze. Check for a blue or waxy patina, known as a bronze patina. Bronze is usually light brown in color. Determine the mass and volume of the metal sample to calculate the density. The density of bronze at room temperature is 8.96 g/cm3 cubed.
How and with what to clean brass, polishing and protecting brass
Before you start cleaning brass, make sure it is actually brass. We’ll tell you how to distinguish brass from bronze - to do this, use a regular magnet and see if it will be magnetized to the “brass”. If so, the item is not brass, it is just plated brass.
If you find out that the item is not made of brass, but is only coated with it, you should avoid any type of abrasive cleaners and tools. The brass plating can be quite thin, which can potentially damage the material.
How to clean brass
Dust, dirt and grease all cast a shadow on brass, giving it age, which is not always a bad thing, especially when it comes to antiques. The patina protects the brass from further environmental erosion. If a brass item you are interested in needs to be cleaned from household dirt, but your goal is not to restore the shine of the material, just rinse the item in soapy water.
How to solder brass with tin
Recipe for brass cleaning solution:
- 2 cups warm water
- 2 teaspoons dish soap
Spray the cleaning solution onto the brass item. If the dirt is stubborn, leave the solution for a few minutes. Wipe the brass with a clean cloth to remove dirt and stains. Rinse with clean water. Dry with a soft cloth.
Polishing brass
Mix the juice of one lemon with a little mineral salt or baking soda to make a brass polish. Apply the mixture using a soft cloth in a circular motion. Use a soft toothbrush to help you reach hard-to-reach places. Rinse with water to remove polish. Dry the item with a soft cloth.
Polishing lacquered brass
If you happen to be working with lacquered brass, you will have to remove a layer of varnish before you can remove the tarnish. Use chemical nail polish removers, but remember to wear gloves, and if the item you're looking for is small enough, you can submerge it in a pan of water.
Bring 3 quarts of water to a boil in a non-aluminum saucepan with one cup of baking soda (soda). Boil until the varnish floats to the surface of the water as a white material.
You can dip the item in boiling water, wait a few minutes, remove it, and remove the cracked varnish by hand. After removing the varnish, clean and polish the brass by hand as described above. Apply a new coat of varnish to the brass.
You want a very thin layer that can be applied with a small brush. Let the varnish dry.
Source: https://respect-kovka.com/latun-magnititsya-ili-net/
Is brass magnetic or not, how can you tell? — Natural Treasures
Anyone who searches for and sells non-ferrous metal sometimes has doubts about the type of scrap and, accordingly, its true value upon delivery.
Copper is a non-ferrous metal, and brass is an alloy that is typically 70% copper, so it often resembles it.
A mistake can be quite costly. For copper at collection points they give 285-300 rubles, for brass - about 150 . There are many ways to find out what kind of metal we see - copper or brass, and we will tell you how to distinguish them from each other in this article.
What is copper and brass
Copper is a non-ferrous metal. Its color is reddish-pink, it is pliable when working, soft and malleable. It has high thermal and electrical conductivity, so copper is often used to produce:
- parts of electrical appliances;
- cables;
- radiators.
Copper is not hardened because it becomes hard even after cold forging. It tends to become covered with patina - a green coating that occurs when the ambient humidity is high.
To increase strength, improve a number of other indicators and reduce the cost of the material, impurities are added and an alloy is obtained.
One such alloy is brass .
In the classic version it contains a third of zinc.
Brass is golden yellow, stronger and harder. It does not oxidize so intensively , and is not so plastic.
Sometimes, depending on the purpose of the alloy, they add:
- tin;
- silicon;
- lead;
- manganese.
Similarities and differences
Brass alloy consists mostly of copper, so it is natural that they are similar not only visually, but also in some properties. The more copper in the alloy, the more similar their colors will be. This is where the exact coincidences end.
Visually, less than 80% copper are easily distinguished . They are slightly similar to gold, as they have a pronounced yellow tint. The more zinc, the lighter the shade.
Because of this, brass is even used to counterfeit or imitate gold . Copper has a main shade of reddish, which often has a pink tint.
With a strong decrease in temperature, brass does not lose its relatively limited ductility and does not become brittle . Conducts electricity and heat worse.
They differ in such a way as hardness .
Copper is softer and more ductile , while brass, on the contrary, is hard and it is difficult to give it any shape without annealing.
The shavings are also different: for brass they are needle- shaped , for copper they are twisted into a spiral .
Let's look at the properties that brass and copper have and whether they have any differences:
| Copper | Brass |
| Plastic, soft | Solid |
| Reddish-brown-pink tint | Golden tone |
| Lower sound on impact | Alt |
| Heavy | Easier |
| The shavings are twisted into a spiral | Needle shavings |
Most often you can distinguish by:
- mind;
- weight;
- degree of hardness
without the use of any tools or equipment.
But there are situations when, for accuracy, it is necessary to use :
- reagents,
- tools,
- devices.
Before assessing the scrap that you are going to take to the collection point, you need to clean it of dirt, otherwise you won’t be able to accurately determine it by eye.
Both metals, although to varying degrees, can develop a patina .
Therefore, do not forget to clean the scrap well.
If an object has been in the open air or in water for a long time, the patina layer is difficult to remove.
Sometimes it will be justified to purchase a special cleaning product .
It is advisable to inspect the scrap under a powerful white light.
This implies that one can view either under the sun on a fine day or under a bright fluorescent lamp . Incandescent lamp is not suitable.
Pure copper will have a reddish-brown tint, sometimes with a pink tint. Keep in mind that brass can be red or orange. This type is commonly used for decorations and water pipes.
If the material has an orange, yellow or golden tint, you can be almost sure that it is brass.
Source: https://22av.ru/osobennosti/latun-magnititsya-ili-net-kak-opredelit.html
