Is copper magnetic or not?

Magnetic susceptibility of substances and elements (Table)

The reference tables give the specific magnetic susceptibility  χ of some para- and diamagnetic bodies, which for isotropic bodies is determined by the expression:

χ = Y/H

where Y denotes the magnetization 1g of the body, and H is the strength of the external magnetizing field.

Table of magnetic susceptibility χ for elements

Solids are assumed to be in an isotropic state. Temperatures (t °C) correspond to the centigrade scale.

Elements	t (°C)	χ-10β
Nitrogen	18	-0,34
Aluminum	18	+0,65
Argon	18	-0,48
Barium	20	+0,91
Bismuth	18	-1,38
260	-1,02
Hydrogen	18	-1,98
Tungsten	16	+0,28
Helium	18	-0,47
Gold	18	-0,15
-256,6	-0,13
Iridium	25	+0,14
200	+0,17
450	-0,20
850	-0,26
1150	+0,31
Cadmium	18	-0,18
Potassium	20	+0,52
Calcium	20	+1.10
Oxygen	20	+106,2
Liquid oxygen	-195	+259,6
Oxygen solid	-240	+60
Silicon	20	-0,13
Lithium	16	+0,50
Magnesium	18	+0,55
Liquid magnesium	700	+0,55
Manganese	22	+9,9
Copper	18	-0,085
Molybdenum	18	+0,04
Sodium	18	+0,51
Neon	18	-0,33
Tin	18	+0,025
Tin gray	18	-0,35
Liquid tin	400	-0,036
Palladium	18	+5,4
200	+4,6
750	+2,6
1230	+1,7
Platinum	18	-1,10
250	-0,66
700	-0,45
1220	+0,30
Mercury	18	-0,19
Solid mercury	—80	-0,15
Lead	16	-0,11
Lead liquid	330	-0,08
Sulfur diamond	18	-0,49
Liquid sulfur	113	-0,49
220	-0,49
Silver	16	-0,20
Antimony	16	-0,87
Liquid antimony	800	-0,49
Tantalum	18	+0,87
820	+0,77
Carbon diamond	18	-0,49
400	-0,51
1200	-0,56
Carbon graphite	20	-3,5
-170	-6,0
600	-2,0
1000	-1,3
Phosphorus white	20	-0,90
Chlorine liquid	-60	-0,57
Chromium	18	+3,6
1100	+4,2
Zinc	18	-0,157
Liquid zinc	450	-0,09
Erbium	18	+22

Table of magnetic susceptibility χ for some compounds, organic and inorganic

Solids are assumed to be in an isotropic state. Temperatures (t °C) correspond to the centigrade scale.

Substance	t (°C)	χ-10β
Aluminum sulfate	18	-0,48
Aluminum chloride	19	-0,60
Ammonia (gas)	16	-1,1
Acetone	15	-0,58
Barium sulfate	—	-0,306
Barium chloride	15	-0,41
Beryllium chloride	17	-0,60
Benzene	16,8	-0,71
Bismuth iodide	20	-0,49
Bismuth bromide	19	-0,33
Water	10	-0,72
Hydrogen chloride	22	-0,66
Air	20	+24,2
Gadolinium chloride	18	+91
Gadolinium oxide	20	+130,1
Glycerol	20	-0,54
Iron oxide	20	189,1
Bromine iron	18	+48
Iron sulfate	19	4,2
Iron chloride	17	+101,2
Ferric chloride	20	+86,2
Potassium bromide	—	-0,377
Potassium iron sulfide	21	,08
Potassium permanganate	21	+0,175
Potassium chloride	20	-0,52
Quartz	20	-0,49
Acetic acid	20	-0,53
Nitric acid	22	-0,467
Sulfuric acid	22	-0,44
Cobalt chloride	25	+90,5
Cobalt iodide	18	+32,0
Cobalt sulfate	22	59,6
Magnesium bromide	20	-0,57
Magnesium chloride	12	-0,58
Manganese sulfate	24	88,5
Manganese chloride	24	107,0
Sodium chloride	18	-0,50
Sodium sulfate	16	-0,86
Oil	15-20	OK. -0.8
Nickel bromide	18	+19,0
Nickel oxide	—	+48,3
Nickel sulfate	15,9	+26,7
Nickel chloride	24	+44,7
Tin dichloride	—	-0,34
Paraffin	20	OK. -0.5
Lead bromide	20	-0,28
Lead iodide	19	-0,33
Lead chloride	15	-0,32
Butyl alcohol	—	-0,74
Methyl alcohol	-3	-0,65
Ethanol	19	-0,74
Glass (crown)	—	-0,90
Glass (heavy flint)	-1,2
Antimony trichloride	15	-0,36
Antimony trioxide	14	-0,19
Carbon dioxide	18	-0,42
Chloroform	15	-0,49
Chromium chloride	19	+44,3
Chrome sulfate	21	+29,5
Chromium trioxide	17	+0,51
Zinc bromide	19	-0,40
Zinc sulfate	—	-0,48
Zinc chloride	22	-0,47
Shellac	—	-0,30
Ebonite	20	+0,6
Ethyl acetate	6	-0,607
Ethylene	20	-1,6
Ethylene chloride	—	-0,602
Ethyl ether	20	-0,77

_______________

Source: https://infotables.ru/fizika/371-magnitnaya-vospriimchivost

Is Copper Magnetic? - Metalist's Handbook

February 24, 2015.

In the magnetic circuits of various electrical machines, transformers, instruments and apparatus of electrical engineering, radio engineering and other branches of technology, a variety of magnetic and non-magnetic materials are found.

The magnetic properties of materials are characterized by the values ​​of magnetic field strength, magnetic flux, magnetic induction and magnetic permeability.

The relationship between magnetic induction and magnetic field strength, expressed graphically, forms a curve called a hysteresis loop. Using this curve, you can obtain a series of data characterizing the magnetic properties of the material.

An alternating magnetic field causes the appearance of eddy currents in magnetic materials. These currents heat the cores (magnetic cores), which leads to the consumption of some power.

To characterize a material operating in an alternating magnetic field, the total value of power expended on hysteresis and eddy currents at a frequency of 50 Hz is referred to 1 kg of material weight. This value is called specific losses and is expressed in W/kg.

The magnetic induction of a particular magnetic material should not exceed a certain maximum value, depending on the type and quality of the material. Attempts to increase induction lead to increased energy losses in a given material and its heating.

Magnetic materials are classified as soft magnetic and hard magnetic.

Magnetic soft materials

Soft magnetic materials must meet the following requirements:

1. have a large relative magnetic permeability µ, which makes it possible to obtain a large magnetic induction B with the smallest possible number of ampere-turns;
2. have the lowest possible losses due to hysteresis and eddy currents;
3. have stable magnetic properties.

Soft magnetic materials are used as magnetic cores of electrical machines, transformer cores, chokes, relay electromagnets, electrical measuring instruments, and the like. Let's look at some soft magnetic materials.

Electrical hardware

obtained by electrolysis of sulphide or ferric chloride, followed by melting in vacuum of the electrolysis products. Powdered electrolytic iron is used for the production of magnetic parts, similar to the production of ceramics or plastics.

Carbonyl iron

obtained in the form of a powder as a result of the thermal decomposition of a substance that includes iron, carbon and oxygen [Fe(CO)5].

At a temperature of 1200 °C, carbonyl iron powder is sintered and used to manufacture the same parts that are made from electrolytic iron. Carbonyl iron is characterized by high purity and ductility; used in the electrovacuum industry, as well as in instrument making for the manufacture of laboratory instruments and devices.

The two types of highly pure iron we considered (electrolytic and carbonyl) contain no more than 0.05% impurities.

Electrical steel sheets

is the most common material in electrical engineering and transformer manufacturing. Electrical steel is alloyed with silicon to improve its magnetic properties and reduce hysteresis losses. In addition, as a result of the introduction of silicon into the steel composition, its resistivity increases, which leads to a decrease in eddy current losses.

Sheet thickness depending on the steel grade is 0.3 and 0.5 mm. Electrical steel, cold rolled and then annealed in a hydrogen atmosphere, has particularly high magnetic properties. This is explained by the fact that the metal crystals are located parallel to the rolling direction. This steel is designated by the letters KhVP (cold-rolled high permeability, textured).

Steel sheets have dimensions from 1000 × 700 to 2000 × 1000 mm.

The grades of electrical steel used to be designated, for example, as follows: E3A, E1AB, E4AA. The letter E means electrical steel; letter A – reduced power losses in an alternating magnetic field; letters AA - especially low losses; letter B – increased magnetic induction; numbers 1 – 4 show the amount of silicon contained in steel as a percentage.

According to GOST 802-54, new designations for electrical steel grades have been introduced, for example: E11, E21, E320, E370, E43. Here the letter E stands for electrical steel; first numbers: 1 – lightly doped with silicon; 2 – medium doped with silicon; 3 – highly alloyed with silicon and 4 – highly alloyed with silicon.

The second digits in the designation of grades indicate the following guaranteed magnetic and electrical properties of steels: 1, 2, 3 – specific losses during magnetization reversal of steels at a frequency of 50 Hz and magnetic induction in strong fields; 4 – specific losses during magnetization reversal of steels at a frequency of 400 Hz and magnetic induction in average fields; 5, 6 – magnetic permeability in weak fields (H less than 0.01 A/cm); 7, 8 – magnetic permeability in medium fields (H from 0.1 to 1 A/cm). The third digit 0 indicates that the steel is cold-rolled, textured.

Permalloy

an alloy of iron and nickel. Approximate composition of permalloy: 30–80% nickel, 10–18% iron, the rest copper, molybdenum, manganese, chromium. Permalloy is easily processed and is available in sheet form. It has very high magnetic permeability in weak magnetic fields (up to 200,000 H/cm). Permalloy is used for the manufacture of telephone and radio communication parts, transformer cores, inductors, relays, and parts of electrical measuring instruments.

Alsifer

an alloy of aluminum, silicon and iron. The approximate composition of alsifer is: 9.5% silicon, 5.6% aluminum, the rest is iron. Alsifer is a hard and brittle alloy, so it is difficult to process. The advantages of alsifer are high magnetic permeability in weak magnetic fields (up to 110,000 H/cm), high resistivity (ρ = 0.81 Ohm × mm²/m), and the absence of scarce metals in its composition. Used for the manufacture of cores operating in high-frequency installations.

Permendur

an alloy of iron with cobalt and vanadium (50% cobalt, 1.8% vanadium, the rest iron). Permendur is available in the form of sheets, strips and tapes. It is used for the manufacture of electromagnet cores, dynamic loudspeakers, membranes, telephones, oscilloscopes and the like.

Magnetodielectrics

These are magnetically soft materials, crushed into small grains (powder), which are isolated from one another by resins or other binders. Electrical iron, carbonyl iron, permalloy, alsifer, magnetite (feO Fe2O3 mineral) are used as magnetic material powder.

Insulating binders are: shellac, phenol-formaldehyde resins, polystyrene, liquid glass and others. The magnetic material powder is mixed with an insulating binder, thoroughly mixed, and from the resulting mass the cores of transformers, chokes, and radio equipment parts are pressed under pressure.

The granular structure of magnetodielectric materials causes low losses due to eddy currents when these materials operate in magnetic fields of high-frequency currents.

Hard magnetic materials

Hard magnetic materials are used to make permanent magnets. These materials must meet the following requirements:

1. have a large residual induction;
2. have a high maximum magnetic energy;
3. have stable magnetic properties.

The cheapest material for permanent magnets is carbon steel (0.4 - 1.7% carbon, the rest is iron). Magnets made of carbon steel have low magnetic properties and quickly lose them under the influence of heat, shock and shock.

Alloy steels have better magnetic properties and are used for the manufacture of permanent magnets more often than carbon steel. These steels include chromium, tungsten, cobalt and cobalt-molybdenum.

For the manufacture of permanent magnets, alloys based on iron - nickel - aluminum have been developed in technology. These alloys are characterized by high hardness and brittleness, so they can only be processed by grinding. The alloys have exceptionally high magnetic properties and high magnetic energy per unit volume.

Table 1 shows data on the composition of some hard magnetic materials for the manufacture of permanent magnets.

Table 1

Chemical composition of magnetically hard materials

Name of material	Chemical composition in weight percent	Relative weight per unit magnetic energy
Carbon steel Chromium steel Tungsten steel Cobalt steel Cobalt-molybdenum steel Alni Alnisi AlnicoMagnico	0.45 C rest Fe 2 – 3 Cr; 1 C 5 W; 1 C 5 – 30 Co; 5 – 8 Cr; 1.5 – 5 W 13 – 17 Mo; 10 – 12 Co 12.5 Al; 25 Ni; 5 CH 14 Al; 34 Ni; 1 Si 10 Al; 17 Ni; 12Co; 6 CH24 Co; 13 Si; 8 Al; 3 Dc	26,7 17,2 15,8 5,1 – 12,6 3,8 3,6 3,4 3,11

Non-magnetic materials

In various instruments and devices used in electrical engineering, it is necessary to have a material that does not have magnetic properties. Plastic and non-ferrous metals (aluminum, brass, bronze) are suitable for such purposes. However, these materials have low mechanical strength, and some of them are in short supply. In this regard, they are being replaced by non-magnetic steel and non-magnetic cast iron.

The approximate composition of non-magnetic steel is: 0.25 - 0.35% carbon, 22 - 25% nickel, 2 - 3% chromium, the rest is iron. Non-magnetic steel is used for coupling and fastening of transformers, chokes, inductors and the like.

The approximate composition of non-magnetic cast iron is: 2.6 - 3% carbon, 2.5% silicon, 5.6% manganese, 9 - 12% nickel, the rest is iron.

Non-magnetic cast iron is used for the manufacture of covers, casings, bushings, oil switches, cable couplings, and casings for welding transformers.

Source: https://ssk2121.com/magnititsya-li-med/

What metals does a neodymium magnet attract?

Only steels have magnetic properties , and not all of them. For example, austenitic stainless steels do not attract magnets because they do not have ferromagnetic properties. However, there are a sufficient number of enthusiasts who believe that magnetic waves are emitted by any metal, and therefore there should be a search magnet for gold and silver, and for some this expression is quite normal for perception and practical use.

ATTENTION! MAGNETS FOR SEARCHING GOLD, COPPER, SILVER DO NOT EXIST!

THEY SIMPLY ARE NOT - ANYWHERE!

In our article we describe the theory of how non-ferrous and precious metals can be detected using magnetic fields. This article is our fantasy, supported by scientific developments of foreign scientists.

See also the article - Extraction of scrap metal from water (about ferrous metal and search magnet).

Device for adjusting the magnetic field from metal objects

Strictly speaking, this is not a magnet, but rather an electromagnet, with the help of which you can initiate and configure any magnetic radiation, even quite weak ones, to be captured by appropriate devices. It is not easy to build such a device, but the authors, citizens of Australia, have no doubt about its effectiveness.

That's why they patented their invention in their patent office. Based on the fact that Australian soil is not much different from domestic soil, we will give a description of the device and operating principle of such a magnet for gold and silver.

Although it is necessary to repeat - in the generally accepted sense, this design has nothing .

The operation of the device is based on the well-known physical fact that when any object that generates magnetic oscillations in an alternating electric field moves, changes occur inside the trapper circuit associated with the movement of atoms around the nucleus.

If the area of ​​electric field generation is sequentially moved along or across the magnetic field from a metal object, changes will occur in this area, the intensity of which determines the degree and strength of the interaction of two fields - magnetic and electric.

The difficulty is that strong magnetic fields are not created by noble metals . It is known, for example, that, according to the principle of decreasing, the electrochemical potentials of non-ferrous metals are located as follows (we consider only the area of ​​interest to us): copper → mercury → silver → palladium → platinum → gold.

Thus, if the expression “is copper attracted to a magnet” may still have some basis, then the phrase “magnet for gold” does not make any sense at all.

It is more correct to talk about an electromagnetic trap, which will record the fact of a coordinated change in electric and magnetic fields in a certain, rather local, metallic volume.

— how copper interacts with a magnet:

Recording of changes that occur in the apparatus under the influence of such fields is captured by the measuring circuit. It is a highly sensitive spring made of rhenium, a rare metal that is absolutely insensitive to temperature changes. The rhenium spring must be adjusted to operate.

  The process is to set the conditional zero of the device, for which it is placed as far as possible from all metal objects. In urban areas, such a “search magnet for gold, silver and other precious metals” will not work. However, search engines are much more likely to look for gold, platinum, copper, silver, etc.

in old abandoned rural estates

With any movement of the device, a similar action occurs with the electric field, while the magnetic field remains constant in coordinates. Therefore, the resulting movement of the spring will also be different.

Where it turns out to be most intense, its source is almost certainly located - the magnetic field. Another thing is that this kind of search magnet for non-ferrous metals will not be able to show which metal is hidden under the thickness of wood or earth.

But the device will definitely show that there is metal there.

Any metal can be detected by a magnetic field

The principle of operation of such a pseudo-magnet is similar to the coils of a metal detector, with the only difference being that the “magnet” will be tuned to only 1 metal and this is in theory - but we don’t know how it will behave in practice, BUT, most likely, it’s cheaper, faster and simpler will use an ordinary metal detector to search for non-ferrous metals, since not a single wizard has yet invented a magnet for non-ferrous and precious metals, maybe because there are no wizards!

How to assemble and set up

It will be very difficult to find/buy a rhenium spring, but all other parts of the device are quite accessible for making yourself. The sequence is:

1. A steel axle is made from a thin-walled steel pipe with a diameter of no more than 16 mm. Its length should not be less than three diameters, otherwise the change in the magnetic field cannot be detected.
2. A frame is made from thin copper or brass wire. The authors do not describe its dimensions, but, based on the dimensions of the tubular axis, it should be at least 200x200 mm. The frame must be sufficiently rigid.
3. Three (as many as possible) holes are drilled in the tubular axle at equal distances, in which the wooden axles are placed.
4. Thin-walled wooden disks are made, the number of which must correspond to the number of holes drilled in the axle. Obviously, discs can also be made of plywood: what matters is the mass of the disc and its absolute immunity to magnetic fields.
5. The central sectors of each disk are covered with metal foil made of the metal that will be searched. Thus, a search magnet for non-ferrous metals - copper, gold and silver (platinum is searched for much less frequently) should have three sets of replaceable wooden disks.
6. The frame with disks must be able to move freely along the entire tubular axis with fixation in a certain place. If the fits of the mating parts are made with the required accuracy, then there should be no swaying of the frame when it moves.
7. To create a magnetic trap, plates from an old transformer are used, which are packed into the frame outline. The distance between adjacent plates should not exceed 1.5 mm in thickness and 56 mm in length. Such plates form the screen of the device that perceives magnetic radiation.
8. Next, assemble the magnetic coil. You will need a solenoid made of 600 layers of enameled wire, which is connected to an alternating current voltage source. The winding should be multilayer, this will reduce the parasitic capacitance of the coil and make the device less inertial.
9. A ferromagnetic or - which is better - a ferroelectric core is inserted inside the coil.
10. By connecting this structure through a step-down transformer, a constant position of the frame with the plates is achieved relative to the wooden disks. This will be the conditional zero of the search “magnet” for non-ferrous metals.

The easiest way to check whether a search “magnet” attracts gold and silver is on a real object made of these metals. At the same time, it will be possible to establish the practical sensitivity of the device.

about how a search magnet does NOT magnetize gold, silver and other coins

Source: http://ooo-asteko.ru/kakie-metally-prityagivaet-neodimovyy-magnit/

Is copper magnetic to a magnet?

February 24, 2015.

In the magnetic circuits of various electrical machines, transformers, instruments and apparatus of electrical engineering, radio engineering and other branches of technology, a variety of magnetic and non-magnetic materials are found.

The magnetic properties of materials are characterized by the values ​​of magnetic field strength, magnetic flux, magnetic induction and magnetic permeability.

The relationship between magnetic induction and magnetic field strength, expressed graphically, forms a curve called a hysteresis loop. Using this curve, you can obtain a series of data characterizing the magnetic properties of the material.

An alternating magnetic field causes the appearance of eddy currents in magnetic materials. These currents heat the cores (magnetic cores), which leads to the consumption of some power.

To characterize a material operating in an alternating magnetic field, the total value of power expended on hysteresis and eddy currents at a frequency of 50 Hz is referred to 1 kg of material weight. This value is called specific losses and is expressed in W/kg.

The magnetic induction of a particular magnetic material should not exceed a certain maximum value, depending on the type and quality of the material. Attempts to increase induction lead to increased energy losses in a given material and its heating.

Magnetic materials are classified as soft magnetic and hard magnetic.

Magnetic properties of copper and its alloys. Is chrome magnetic or not?

ChromeChrome is magnetic or not

One of the most popular types of rolled metal is heat-resistant stainless steel, grades of which are able to retain their properties at high temperatures, incl. in aggressive environments. Containers and equipment made from such alloys are effectively used for hot liquids, caustic acid solutions, and in the manufacture of parts for heating devices and boilers.

For the material itself, designations make it easy to determine the composition and purpose. For welding consumables such as stainless steel electrodes, the marking determines their use and classification:

• Consumable wire electrodes - copper, aluminum, steel, cast iron, etc.;
• Non-melting - tungsten, graphite (synthetic). Special coal is also used for electrical equipment;

Stainless steel grade

In the CIS, USA, Asian countries and the EU, stainless steel grades and their characteristics are slightly different. In particular, we are talking about the amount of chromium, nickel, and other alloying additives in the alloy. In this regard, Russian designations are somewhat more convenient, because allow you to immediately find out the composition.

For example, 08Х18Н10 is 0.8% carbon, 18% chromium and 10% nickel. The closest foreign analogue received the designation AISI 304. The Regional House of Metal company sells domestic and American formats, where the marking uses not only numbers, but also letters.

They usually mean either carbon content or additional alloying additives:

• Ti – titanium;
• Cu – copper;
• N – nitrogen, and others.

The properties of each steel are different. For example, the price of stainless steel depends on whether it is austenitic or low-carbon. It shows excellent resistance to the destructive effects of corrosion. Having a composition similar to AISI 304, this steel is more reliable due to its higher nickel content and additional alloying with molybdenum. The scope of application depends on the properties.

Stainless steel grades

The Regional House of Metal company sells steels with different properties. We suggest you purchase the most popular brands of magnetic stainless steel. These include ferritic alloys, such as AISI 430. Martensitic steels are best magnetic. Ferritic alloys exhibit this property, depending on the composition. AISI 409, 08x13 and many others are also magnetized.

For comparison, grade 304 stainless steel is austenitic and therefore not magnetic. But it is universal in use. You can use it to make a table for cutting meat, a chimney, metal utensils, and other products.

How can marking stainless steel help determine magnetic properties? Everything is very simple. You need to look at how much nickel is in the alloy. At 10% or more, the material stops being magnetic.

rdmetall.ru

AISI 430 is magnetic or not

You can place an order by phone

Our specialists will be happy to help you

Source: https://www.consei.ru/hrom/hrom-magnititsya-ili-net.html

Why is copper not magnetic?

February 24, 2015.

In the magnetic circuits of various electrical machines, transformers, instruments and apparatus of electrical engineering, radio engineering and other branches of technology, a variety of magnetic and non-magnetic materials are found.

The magnetic properties of materials are characterized by the values ​​of magnetic field strength, magnetic flux, magnetic induction and magnetic permeability.

The relationship between magnetic induction and magnetic field strength, expressed graphically, forms a curve called a hysteresis loop. Using this curve, you can obtain a series of data characterizing the magnetic properties of the material.

An alternating magnetic field causes the appearance of eddy currents in magnetic materials. These currents heat the cores (magnetic cores), which leads to the consumption of some power.

To characterize a material operating in an alternating magnetic field, the total value of power expended on hysteresis and eddy currents at a frequency of 50 Hz is referred to 1 kg of material weight. This value is called specific losses and is expressed in W/kg.

The magnetic induction of a particular magnetic material should not exceed a certain maximum value, depending on the type and quality of the material. Attempts to increase induction lead to increased energy losses in a given material and its heating.

Magnetic materials are classified as soft magnetic and hard magnetic.

How to determine what we have in front of us: brass or copper, their main differences

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://rcycle.net/metally/cvetnye/kak-opredelit-latun-ili-med-ih-osnovnye-otlichiya

Scrap metal identification

This resource will help clear up any confusion about how to identify different types of metals! First, always have a magnet handy. It's better to have several magnets. Microwaves, speakers, hard drives, and other electronic devices all have a magnet in them that you can pull out. Another great way to identify metal is the spark test.

Using a magnet, you can identify and sort ferrous and non-ferrous metals.

Iron/steel

• 3 times heavier than aluminum
• Rusting
• Has magnetic properties
• There's a lot of it
• Durable

Aluminum

• Light
• Does not have magnetic properties
• Does not throw sparks from the grinder
• Does not rust

Copper

• Mainly used in wiring and electronics
• Large utensils are made from it
• When copper is pure it has a beautiful pink color.
• When tarnished, it is usually red or brown in color. (Also beautiful)
• Oxidizes and turns green
• Denser than iron, approximately 15%
• The brighter the copper, the more valuable it is
• Copper No. 1 pure copper, including pipes without solder joints
• Copper No. 2 copper with soldered joints

Copper scrap: motors, transformers, chokes, some processors and so on.

Brass or bronze

• Typically yellowish in color and worth about half the price of No. 1 copper
• May be called brass or bronze, "copper alloy" to avoid confusion
• Often found in the form of pipe valves, decorations
• Maybe alloyed with nickel, in which case it is called "nickel silver" (see below)

Copper wire grades

There are many different ways to classify copper wire, but it all comes down to the percentage of copper content.

• 85% Wire: the diameter of a pencil. If you have this type of wire, you will get the best price for it
• 70% Wire: wires without any insulation
• 50% Wire: Extension cords and appliance cords with insulation removed
• 30% Wire: Thin wires in a bundle with insulation

How to determine lead

• One and a half times denser than iron, feels heavy
• It is atomic element 82 with the chemical symbol Pb, is very malleable, or soft, and can be cut with a pocket knife
• Melts at low temperature
• Used to make bullets and X-ray machines
• Very toxic

How to identify 304 stainless steel

• 304 stainless steel is an alloy of iron with 18% chromium 8% nickel
• Does not have magnetic properties
• Use a spark test

How to identify 316 stainless steel

• Does not have magnetic properties
• It is an alloy of iron with 18% chromium and 10% nickel
• Looks exactly the same as 304
• When using a spark test, there will be fewer "forks" at the end of the flow
• Use a portable spectrometer for accurate determination

How to identify 200 stainless steel

• It is an alloy of iron with 17% chromium, 4% nickel and 7% manganese
• Much more resistant to corrosion than 300 grade
• Does not have magnetic properties
• Harder to sell to scrap buyers, so 200 steel is hard to accumulate enough to find a buyer

How to identify 400 stainless steel

• It is an alloy of iron with 11% chromium and ~1% manganese
• Does not contain nickel and therefore has magnetic properties
• Due to its magnetic properties, many buyers will not give a high price for it.

How to identify cupronickel

• This is a copper/nickel alloy
• Worth much more than copper 1
• Some will cheat and try to buy this material at the price of copper or cheaper
• In fact, nickel silver contains from 30% to 90% nickel, and it is 3 times more expensive than copper
• Often used in counterfeit jewelry, silver plated cookware, ship parts, heat exchangers and condensers, musical instruments and more

You will have to go around many scrap buyers before they will give you a fair price for cupronickel.

Electric heating elements

• Heating elements from electric stoves are usually made of nickel
• Use a handheld spectrometer for accurate pricing

How to identify carbide (tungsten carbide)

• Carbide is short for tungsten carbide.
• It is heavy, 16 times heavier than water!
• Two tablespoons of carbide weigh more than a kilogram!
• Usually found in the form of tips of cutters, saws
• Produces very short, dull, dark red sparks on spark test
• Very durable

Source: http://metallsam.ru/%D0%98%D0%B4%D0%B5%D0%BD%D1%82%D0%B8%D1%84%D0%B8%D0%BA%D0%B0 %D1%86%D0%B8%D1%8F_%D0%BC%D0%B5%D1%82%D0%B0%D0%BB%D0%BB%D0%BE%D0%BB%D0%BE%D0 %BC%D0%B0

Copper properties

Copper - properties.

Physical, electrical and magnetic, thermal and thermodynamic, optical, mechanical, chemical, technological properties of copper. Applications of copper.

Copper is a component of more than 200 minerals, but only a few of them (approximately 40) are of industrial importance. The most important minerals that make up copper ores are chalcocite, or copper luster; chalcopyrite, or copper pyrite; malachite. Copper ores are complex raw materials, in addition to copper, containing zinc, nickel, molybdenum, cobalt and, in addition, sulfur, selenium, tellurium, indium, germanium, lead, gadolinium, as well as silver and gold.

Currently, ores containing from 0.7 to 3% copper are processed. Copper production is based on the processing of sulfide and oxidized copper ores. More than 80% of copper is obtained by the pyrometallurgical method, the remaining 20% ​​by the hydrometallurgical method. With the pyrometallurgical method, ores are pre-enriched, and then the concentrate is subjected to the actual pyrometallurgical process, consisting of roasting, smelting and converting.

The resulting blister copper is subjected to fire or electrolytic refining. Hydrometallurgical processing consists of leaching ore to transfer copper into solution and then precipitating it from solution. The hydrometallurgical method is used to process mainly low-grade oxidized ores and native copper. Ore in a finely crushed state is subjected to leaching.

The process reagents are usually sulfuric acid solution or ammonia solutions. Precipitation of copper from its sulfuric acid solutions obtained as a result of leaching is carried out by electrolytic method (electrolysis with insoluble anodes) or cementation (precipitation with iron). When leaching with ammonia solutions after their decomposition with live steam, copper is released in the form of CuO.

Cementation copper and copper obtained by decomposition of ammonia solutions are supplied to special plants for refining or processing.

Copper is a pink-red metal, belongs to the group of heavy metals, and is an excellent conductor of heat and electric current. The electrical conductivity of copper is 1.7 times higher than that of aluminum and 6 times higher than that of iron. The Latin name for copper Cuprum comes from the name of the island of Cyprus, where already in the 3rd century. BC e.

There were copper mines and copper was smelted. Around the 2nd - 3rd century. Copper smelting was carried out on a large scale in Egypt, Mesopotamia, the Caucasus, and other countries of the ancient world.

But, nevertheless, copper is far from the most common element in nature: the copper content in the earth’s crust is 0.01%, and this is only the 23rd place among all elements found.

In industrial production and in the repair of equipment components for various purposes, copper alloys - bronze and brass - are widely used. For bronze alloys - the properties of bronze, for alloys of copper with zinc (brass) - the properties of brass, the use of brass.

Of course, the most widely used in modern industry is iron and its alloys - steel; the properties of ferrous metals and the properties of steel allow, due to their relative cheapness, to largely replace more expensive non-ferrous metals.

Properties of non-ferrous metals: Aluminum, copper, brass, bronze in English.

 Copper production

In nature, copper is present in the form of sulfur compounds, oxides, hydrocarbonates, carbon dioxide compounds, as part of sulfide ores and native copper metal. The most common ores are copper pyrite and copper luster, containing 1-2% copper. 90% of primary copper is obtained by pyrometallurgical method, 10% by hydrometallurgical method.

The hydrometallurgical method is the production of copper by leaching it with a weak solution of sulfuric acid and subsequent separation of copper metal from the solution. The pyrometallurgical method consists of several stages: enrichment, roasting, smelting for matte, purging in a converter, refining.

To enrich copper ores, the flotation method is used (based on the use of different wettability of copper-containing particles and waste rock), which allows one to obtain copper concentrate containing from 10 to 35% copper. Copper ores and concentrates with high sulfur content are subjected to oxidative roasting. In the process of heating the concentrate or ore to 700-800°C in the presence of atmospheric oxygen, sulfides are oxidized and the sulfur content is reduced by almost half of the original.

Only poor concentrates (with a copper content of 8 to 25%) are fired, and rich concentrates (from 25 to 35% copper) are melted without firing. After roasting, the ore and copper concentrate are smelted into matte, which is an alloy containing copper and iron sulfides. Matte contains from 30 to 50% copper, 20-40% iron, 22-25% sulfur, in addition, matte contains impurities of nickel, zinc, lead, gold, and silver. Most often, smelting is carried out in fiery reverberatory furnaces.

The temperature in the melting zone is 1450°C. In order to oxidize sulfides and iron, the resulting copper matte is subjected to blowing with compressed air in horizontal converters with side blast. The resulting oxides are converted into slag. The temperature in the converter is 1200-1300°C. Interestingly, heat is released in the converter due to chemical reactions, without fuel supply.

Thus, the converter produces blister copper containing 98.4 - 99.4% copper, 0.01 - 0.04% iron, 0.02 - 0.1% sulfur and a small amount of nickel, tin, antimony, silver, gold. This copper is poured into a ladle and poured into steel molds or a casting machine. Next, to remove harmful impurities, blister copper is refined (fire refining and then electrolytic refining are carried out).

The essence of fire refining of blister copper is the oxidation of impurities, removing them with gases and converting them into slag. After fire refining, copper with a purity of 99.0 - 99.7% is obtained. It is poured into molds and ingots are obtained for further smelting of alloys (bronze and brass) or ingots for electrolytic refining. Electrolytic refining is carried out to obtain pure copper (99.95%).

Electrolysis is carried out in baths where the anode is made of fire-refined copper, and the cathode is made of thin sheets of pure copper. The electrolyte is an aqueous solution. When a direct current is passed, the anode dissolves, the copper goes into solution, and, cleaned of impurities, is deposited on the cathodes. Impurities settle to the bottom of the bath in the form of slag, which is processed to extract valuable metals. The cathodes are unloaded after 5-12 days, when their weight reaches 60 to 90 kg.

They are thoroughly washed and then melted in electric furnaces. In addition, there are technologies for obtaining copper from scrap. In particular, refined copper is obtained from scrap by fire refining. According to purity, copper is divided into grades: M0 (99.95% Cu), M1 (99.9%), M2 (99.7%), M3 (99.5% ), M4 (99%). Chemical properties of copper Copper is a low-active metal that does not interact with water, alkali solutions, hydrochloric and dilute sulfuric acid.

However, copper dissolves in strong oxidizing agents (for example, nitrogen and concentrated sulfur). Copper has a fairly high resistance to corrosion. However, in a humid atmosphere containing carbon dioxide, the surface of the metal becomes covered with a greenish coating (patina). Basic physical properties of copper Melting point °C1084 Boiling point °C2560 Density, γ at 20°C, kg/m³8890 Specific heat at constant pressure, Cp at 20°C, kJ/(kg•J) 385 Temperature coefficient of linear expansion, a•106 from 20 to 100 °C, K-116.8 Electrical resistivity, p at 20°C, μΩ•m0.01724 Thermal conductivity λ at 20°C, W/(m•K) 390 Electrical conductivity, ω at 20°C, MOhm/m58

Mechanical properties of copper

Properties Condition Deformed Annealed Tensile strength, σ MPa 340 - 450 220 - 245 Relative elongation after break, δ ψ% 4 - 645 - 55 Relative contraction after break, % 40 - 6065 - 80 Brinell hardness, HB90 - 11035 - 55 At negative temperatures, copper has more high strength properties and higher ductility than at a temperature of 20°C. Commercial copper has no signs of cold brittleness. As the temperature decreases, the yield strength of copper increases and the resistance to plastic deformation increases sharply. Copper Applications

The properties of copper, such as electrical conductivity and thermal conductivity, have determined the main area of ​​application of copper - the electrical industry, in particular, for the manufacture of wires, electrodes, etc. For this purpose, pure metal (99.98-99.999%) that has undergone electrolytic refining is used.

Copper has numerous unique properties: corrosion resistance, good manufacturability, a fairly long service life, and goes well with wood, natural stone, brick and glass. Due to its unique properties, this metal has been used in construction since ancient times: for roofing and decorating building facades. The service life of copper building structures is hundreds of years.

In addition, parts of chemical equipment and tools for working with explosive or flammable substances are made from copper. A very important application of copper is the production of alloys. One of the most useful and most commonly used alloys is brass (or yellow copper). Its main components are copper and zinc. Additions of other elements make it possible to obtain brass with a wide variety of properties.

Brass is harder than copper, malleable and tough, so it can be easily rolled into thin sheets or stamped into a wide variety of shapes. One problem: it turns black over time. Bronze has been known since ancient times. It is interesting that bronze is more fusible than copper, but its hardness is superior to individual pure copper and tin.

If 30-40 years ago only alloys of copper and tin were called bronze, today aluminum, lead, silicon, manganese, beryllium, cadmium, chrome, and zirconium bronzes are already known. Copper alloys, as well as pure copper, have been used for a long time for the production of various tools, utensils, and are used in architecture and art. Copper coins and bronze statues have decorated people's homes since ancient times.

Bronze products from masters of Ancient Egypt, Greece, and China have survived to this day. The Japanese were great masters in the field of bronze casting. The giant Buddha figure at Todaiji Temple, created in the 8th century, weighs more than 400 tons. To cast such a statue required truly outstanding skill.

About copper

Among the goods that Alexandrian merchants traded in ancient times, “copper greens” were very popular. Fashionistas used this paint to add green circles under their eyes - in those days it was considered a sign of good taste. Since ancient times, people have believed in the miraculous properties of copper and used this metal to treat many ailments.

It was believed that a copper bracelet worn on a hand would bring good luck and health to its owner, normalize blood pressure, and prevent salt deposition. Many peoples still attribute healing properties to copper. Residents of Nepal, for example, consider copper a sacred metal that promotes concentration of thoughts, improves digestion and treats gastrointestinal diseases (patients are given water to drink from a glass containing several copper coins).

One of the largest and most beautiful temples in Nepal is called “Copper”. There was a case where copper ore was responsible for the accident that the Norwegian cargo ship Anatina suffered. The holds of the ship, heading to the shores of Japan, were filled with copper concentrate. Suddenly an alarm sounded: the ship had developed a leak.

It turned out that the copper contained in the concentrate formed a galvanic couple with the steel body of the Anatina, and the evaporation of sea water served as an electrolyte. The resulting galvanic current corroded the ship's hull to such an extent that holes appeared in it, into which ocean water poured.

Source: http://polias.ru/index/0-9

IT News

Date Category: Physics

When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.

The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.

The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.

Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.

Magnetic chain

Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.

Countless little magnets

Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.

Formation of a permanent magnet

1. Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear.
2. If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines).
3. Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.

Source: http://Information-Technology.ru/sci-pop-articles/23-physics/231-pochemu-magnit-prityagivaet-zhelez

Is copper magnetic or not: reasons and methods for determining

Sometimes at home you need to distinguish copper from another metal, and also check the cleanliness of a copper product and whether there are any foreign impurities in it. This can be done based on the appearance of the metal, as well as on determining its properties, in particular, by conducting a test with a magnet.

• general information
• Magnet check
• Alloys

general information

Copper (cuprum) is a metal that has a golden-reddish color and is characterized by high thermal and electrical conductivity. Another distinctive quality of the element is its high ductility. Nuggets are found less and less often in nature; they are most often mined from ore.

Is copper magnetic or not?

When determining the authenticity and purity of a sample, you can turn to an expert, but determining a chemical element in a laboratory is quite expensive. Therefore, you need to focus on several home methods.

First of all, we take a closer look at the color of the product. Since this element tends to oxidize, it is necessary to evaluate the cut or cut of the object. For accuracy, take a sample and compare the color. It should be golden-reddish. Gold has similar colors, as do osmium and cesium.

If copper wire is set on fire, it will not burn, but will first lose its shine and then change color to dark.

You can treat the sample with nitric acid - it should acquire a greenish-blue tint.

Magnet check

Electromagnetic waves emitted by the substance are responsible for the magnetic properties of objects. When interacting with a magnet, some metals are attracted, but some do not react, since there is no electromagnetic radiation. Cuprum also belongs to these. This metal is diamagnetic, and therefore will not react to a magnet.

Moreover, the copper field is repelled by the magnet. This unique property has led to the use of metal in electrical products, since under the influence of current it creates the necessary field for the movement of electronic particles. If a magnet is attracted to the sample, it means that it is an alloy in which there is no more than half of the required metal.

But sometimes there are samples that also do not have magnetic properties, although they do not consist of pure copper. This happens when there is aluminum underneath the copper coating. It is also diamagnetic, so aluminum products will not be attracted to a magnet.

An object made of pure cuprum may become magnetic over time if it oxidizes. As a result, a film is created on the surface that has high ferromagnetic properties.

Alloys

The most popular alloys using the element are brass (with the addition of zinc) and bronze. As for brass, it does not react to the electromagnetic field in the same way as cuprum. This is due to the fact that copper in this alloy is at least 55% or more. This alloy differs from the pure sample in terms of weight and also in the shape of the chips.

Bronze also has no electromagnetic field. But this alloy is much stronger than cuprum. If you touch samples with your teeth, traces will remain on pure copper, but not on bronze and brass.

If you look at the periodic table, you won’t be able to immediately find out anything about the magnetic properties of elements. To do this, you need to study this material in a little more detail. Modern production produces composite materials that are indistinguishable from copper (the 29th element of the table).

Therefore, testing with an electromagnetic field can be a reliable test for the presence of impurities and the purity of material that will not be attracted to a magnet.

In addition, at home, heating, removing chips, and also carrying out chemical reactions will help identify cuprum, during which care and safety precautions should be observed.

Source: https://DedAntikvar.com/interesnoe/obladaet-li-med-magnitnymi-svojstvami