Magnets have different influences on devices: some devices are severely damaged, while others are only temporarily altered. Many of the following items have become an integral part of our lives. We use them on a daily basis and it is useful to know which ones are sensitive to magnetic fields, such as permanent magnets, to avoid unintentional loss of data or other functional impairment.
Hearing aid components, e.g. loudspeakers, can be damaged due to the magnetic field strength of 200m Tesla. But also the strengths of 20m Tesla can lead to alterations, which negatively affect the use. Please pay attention to a sufficient safety distance here.
Pacemakers respond to magnets and the physician in charge uses this behavior to perform controls and frequency changes during some cycles. Once the magnet is removed, the pacemaker continues to function as usual. However, as there are many different manufacturers and newer and older models, a general evaluation cannot be performed. In any case, it is safer to stay away from strong magnetic fields and, if in doubt, contact the manufacturer of your pacemaker. Again, it is advisable to keep a distance to the magnets.
The magnetic strips are coated with magnetic metal oxide. You can find them on several plastic cards that almost everyone in your wallet carries and uses every day. Since there are several cards and important data to protect, there are also two different qualities that are used. They are divided into high coercivity (high quality) and low coercivity (lower quality).
The high quality variant is used, for example, for credit and debit cards. The data is erased only with a magnetic force of 0.4 Tesla, but even with a third of the force it can already lead to partial damage. Since magnetic cards can no longer be read correctly in this case, only a coercive field strength of 40m Tesla, i.e. 10% of 0.4 Tesla, guarantees absolute security.
The cheapest variant of low coercitivity can be found, for example, in paper tickets, which are used in car parks or as entrance tickets. The magnetic strips are light brown and much more sensitive than the high quality version. Even a coercive magnetic field strength of 30 m Tesla is sufficient to demagnetize the magnetic stripe and permanently damage the data. Strengths below 3m Tesla provide security against damage to stored data.
Modern mechanical watches are considered anti-magnetic and are manufactured in accordance with the international standard ISO 764, which corresponds to the German standard DIN 8309. This standard defines the resistance of watches to magnets. Magnetic fields can affect some elements of the mechanical watch, such as the helical spring. According to the standard, anti-magnetic watches, even when exposed to a magnetic field of 6m Tesla, can deviate a maximum of 30 seconds per 24 hours. However, some watch manufacturers offer much less sensitive watch models.
For non-magnetic watches, a defined safety distance cannot be specified. On the safe side, you are here if you put your watch without magnetic field around 0.05m Tesla. This corresponds to the earth's natural magnetic field. If you expose an analog quartz watch to a strong magnetic field, it can happen that the watch motor goes faster or slower, or even stops completely. When the magnet is removed and the watch is manually corrected, the quartz watch will generally run the same.
Smartphones, tablets, digital cameras and similar consumer goods generally incorporate mechanical parts and loudspeakers that can be disturbed by very strong magnets, while stored media are safe from magnetic fields. Therefore, keep your electronic devices away from strong magnetic fields when in doubt.
Magnetic fields do not have a negative impact on data stored on USB sticks. By the way, the same applies to CD and DVD data.
Even hard disks can only be deliberately damaged by a magnetic field, because it has to come very close to the hard disk with a very strong magnet. For this, even the hard disk cover would have to be unscrewed; otherwise, it cannot get close enough with the magnet.
The car key and the built-in technology do not suffer any damage when they come into contact with a static magnet.
Conclusion
In short, magnets are harmless to data stored in mobile phones, tablets and digital cameras. They also have no effect on car keys, USB sticks and hard disks unless handled. However, caution should be exercised with pacemakers, hearing aids and watches.
Alnico magnets were the strongest permanent magnets that existed until the introduction of rare earth magnets and, although somewhat displaced, Alnico magnets are still commonly used in various industries for specific jobs such as high temperature handling equipment and sensor manufacturing, among others.
Alnico magnets have long life, excellent temperature stability, high residual induction and relatively high energies due to their composition, a combination of aluminium (al), nickel (ni) and cobalt (co).
This development and introduction of Alnico meant that expensive electromagnets could be replaced with these permanent magnets in essential devices such as motors and generators. But despite not having the prominence of years ago, Alnico magnets still perform better than their successors in specific situations and, therefore, are still used for many applications that require a very high temperature concentration such as;
Electric motor.
Microphones.
Engineering applications.
Aerospace applications.
Military applications.
Commonly used for various types of sensors.
In addition, Alnico magnets are widely used in rotary machinery, meters, instruments, detection devices and retention applications, to name a few.
It should be noted that Alnico is hard and brittle. Therefore, machining or drilling cannot be done by ordinary methods. Holes are usually drilled in the foundry, magnets are molded near the final size and then machined to closer tolerances.
Likewise, Alnico magnets have high magnetic resistance and low resistance to demagnetization and remagnetization.
Main elements of the Alnico
Percentage in weight
Aluminium
(Al)
6% - 13%
Nickel
(Ni)
13% 26%
Cobalt
(Co)
0% - 42%
Copper
(Cu)
2% - 6%
Titanium
(ti)
0% -9%
Niobium
(Nb)
0% -3%
Iron (Fe)
Balance (e.g. 30% -40%)
Excellent temperature stability up to 1,000F.
High residual induction.
Alnico's corrosion resistance is considered excellent and no surface treatments are required.
Past Alnico magnets can be produced in relatively complex shapes.
They can be demagnetized more easily than other magnetic materials.
They are relatively expensive, as they contain nickel and cobalt.
Alnico clot magnets often have cast pores and voids, which can be problematic for appearance and magnetic flux.
Unlike, for example, ferrite magnets, Alnico magnets are generally stronger and are electrically conductive, while they are less fragile than most rare earth magnets and can produce a strong magnetic field. In addition, Alnico magnets can operate at the highest temperatures of any magnetic material and maintain their magnetism even when they are red-hot.
How is this possible? Because of its composition. Alnico magnets are manufactured by casting or sintering processes. Under the first mode of manufacture, a molten metal alloy is poured into a mold and then passed through several heat cycles. The final product is a magnet with a dark grey exterior, with a rough surface, but the machined magnet surfaces have a glossy appearance.
In the second way, they are manufactured by compacting fine Alnico powder in a press and then sintering the compacted powder into a solid magnet.
The typical composition of the Alnico alloy is:
If you are interested in learning more about Alnico magnets, at IMA we have a wide variety of them and help you choose the right model for your needs. If you have any questions, ask us.
In everyday life, there are a lot of objects that use magnets. In fact, even if you can't identify it directly or be aware of it, everything that works around you makes use of magnets and the magnetic field.
Magnets can be found in the simplest or most complex devices you use every day. From home appliances such as the refrigerator, microwave oven and electric fan, to your company's office equipment such as computers and printers. All these devices use magnets.
In this sense, we will now look at 13 objects that use magnets and that we use in our daily lives.
Duvet covers. Magnets are used in some duvet covers to keep them closed.
Hanging art. Hook magnets can be used to hang art from walls and posters. They can also be used to organize closets by hanging scarves, jewelry, belts, and more.
Bags and jewelry. Bags often incorporate magnets in closures. Magnetic closures are also used to make jewelry.
Television. All televisions have cathode ray tubes, or CRTs, and these have magnets inside. In fact, televisions specifically use electromagnets that direct the flow of energy to the corners, sides, and half of your television screen.
Doorbell. It's not exactly in the bedroom, but the doorbell has magnets, and it may have several, and you'll know it simply by listening to the amount of tones it produces. The bells also contain solenoids, which causes a spring-loaded piston to strike a bell. It happens twice, because when you release the button, the magnet passes underneath the piston and causes it to strike.
Microwave magnets. Microwave ovens use magnetrons consisting of magnets to generate electromagnetic waves that heat food.
Refrigerator doors. Refrigerators and freezers are sealed with a magnetic mechanism so they are easy to open from the inside.
Spice and knife rack. A magnetic spice rack with neodymium magnets is easy to make and useful for cleaning valuable counter space. Also a knife rack is excellent for organizing kitchen utensils.
Many cabinet doors are secured with magnetic latches against unintentional opening.
Computers use magnets in a variety of ways. First, the hard drive's disk is covered with small magnets, which allow computers to store data. Then, CRT computer screens are produced as television screens and, of course, use electromagnets.
Organizing office supplies. Neodymium magnets are useful for organization. Metal office supplies such as clips and thumbtacks will stick to the magnet so they don't move.
Extendable tables. Extendable tables with additional pieces can use magnets to hold the table in place.
When you have an outdoor party, use magnets to keep the tablecloth in place. The magnets will prevent it from flying in the wind along with everything that sits on the table. Magnets also won't damage the table with holes or tape residue.
Now, when you use one of these items that use magnets, you won't do it the same way anymore, and you'll probably be a little more attentive to identify the magnet on them. At IMA we have a wide variety of magnets and we can help you choose the one that best suits your needs. If you have any questions, ask us.
Magnets in aerospace engineering have been used for decades and are designed to be used in extreme environments and to work over a long period of time.
In fact, the aerospace industry is a sector that has experienced great technological and scientific advances in recent years. Therefore, as the demands and temperatures of the challenges have increased, it has been necessary to manufacture magnets that support them and successfully accomplish many of the missions we know today.
Magnets in aerospace engineering must have a series of specific attributes that allow them to adapt to the environment in which they will be used, so that, among the basic conditions of use, they must:
To have a reduced weight.
To have small sizes or miniature sizes.
Show impeccable long-term performance in the harshest conditions.
Have a long service life.
A reduced cost.
Greater efficiency and maximum performance.
Higher retention force.
Better traction versus distance.
Reduced amount of rare earth materials.
When designing magnets in aerospace engineering, critical requirements of tensile forces, torques, field strength, temperature and sensor specifications, among others, must be taken into account.
For example, for a critical mission, a permanent magnet can be designed to detect the position of an actuator, detect fluid flow rates, make fuel pumps and operate temperature generators.
But, also, magnets in aerospace engineering help reduce carbon and increase fuel efficiency through miniaturization with the possibility of better recyclability.
For this sector, compression-bound magnets, injection-moulded magnets or hybrid magnets are used. Samarium cobalt is the material commonly used in aerospace and military applications, mainly due to its high working temperature. The new grades NdFeB 30AH and 33AH could be another interesting option with a working temperature of up to 240. Magnets in aerospace engineering are used for:
Missile programs.
Flight control covers for both commercial and combat aircraft.
Aircraft loudspeakers.
Operation of the TWT radar.
PM generator rotor assemblies.
Fuel pump.
Flow regulators.
Development of cryogenic magnets for space.
Magnetic holders for aircraft seats.
Calibration of position and speed sensors.
Operation of air compressors.
Operation of motorized generators.
Operation of tachometer generators.
Electromagnetic propulsion is one of the great uses of magnets in aerospace engineering. In fact, in the case of submarines, the use of magnetic propulsion is fundamental, because with a propellerless, silent and maintenance-free form, it can drive a boat through the water.
The idea of electromagnetic propulsion was first developed in the 1950s precisely for submarines, and at the high speeds promised by electromagnetic propulsion would make them faster than surface ships, which are hampered by waves.
The magnetic propulsion system is applicable to all ships, such as ships, submarines, torpedoes and the like that travel in salt water. To the extent that it can be demonstrated experimentally, the device is also useful as a spatial drive system to provide thrust to a ship traveling in an ionic atmosphere, for example, space.
In practical uses of magnets in aerospace engineering, they are used for captain's cabin controls, for generating electricity with electromagnets, for wing movement, for wing performance and for helicopter propellers. At IMA we help you choose the right model of magnets in aerospace engineering according to your needs. If you have any questions, ask us.
Biomagnetism is a revolutionary, scientific and therapeutic approach to wellness that differs from traditional medicine, homeopathy, herbs and natural therapies, but is perfectly compatible with any other traditional or alternative modality.
It is one of the alternative uses of magnets, representing an internationally practiced health approach that strives to achieve a bioenergetic balance in the human body, i.e., the natural state of health known as "homeostasis".
Biomagnetism first appeared in Mexico City in 1988 and was discovered by physician Isaac Goiz. In this sense, biomagnetism studies, detects, classifies, measures and allows the correction of pH imbalances in living organisms.
It is considered that pH imbalances can accumulate and combine to allow the development of symptoms, syndromes and other health conditions in our bodies. By restoring the body's natural pH balance, different renewed natural defenses can keep different microorganisms, such as viruses, fungi, bacteria and parasites, under control.
For example, when you take a fish out of the water, it can no longer survive in that new environment, no matter how much oxygen or light is available. All fish need water to survive, but some need salt water, while others need fresh water. In addition, everyone who has had an aquarium or pool knows the importance of pH balance in the water.
If we restore the natural pH balance of our body in our liver, lungs, pancreas, kidneys, muscles, joints, stomach, small intestine, large intestine, etc., these organs can begin to function properly again.
Biomagnetism involves the precise and correct placement (north/south polarity) of special high-intensity field magnets over very specific areas of the body, to support pH regulation in these areas. By maintaining an adequate pH, homeostasis can be re-established so that the body can heal itself.
With this type of therapy, it is achieved, among other results:
Stimulate the normal function of the immune system.
Increased circulation and oxygenation.
A normalizing response to inflammation.
According to Dr. Goiz, it is possible to recover healthy metabolic states through the use of biomagnetic fields of medium intensity, produced by 1,000 to 4,000 Gauss magnets, which is no more than the unit used to measure the strength of a magnetic field, applied in pairs in specific parts of the body called Biomagnetic Pairs. This approach is a type of biofeedback, in which the biomagnetic pairs complement each other, leading to homeostasis.
By applying biomagnetism to specific locations in the body, the restoration of adequate pH in that area is allowed and, when present, pathogens cannot survive in this pH environment. The cells become healthy and the body begins to heal.
Finally, the healing process occurs when the pH is balanced and reaches its optimal level that determines the well-being of the person, which before therapy was altered by the presence of pathogenic microorganisms that distorted the levels of acidity and alkalinity (pH) of the organs. This is what sustains the bioenergetic phenomenon.
It is not similar to magnetic therapy. Magnetic therapy has been applied with a polar principle only for dysfunction or lesions according to two concepts:
South Pole as an analgesic
North pole as anti-inflammatory.
The magnetic fields used for this purpose are low intensity (between 100 and 500 gauss) and are applied for long periods of time, hours or days, and in areas that show specific symptoms. The purpose of this explanation is to establish the difference between magnetotherapy and biomagnetism.
Biomagnetism and bioenergetic pairs are vibrational phenomena, unrelated to standard medicine, as they do not suppress symptoms or claim to "cure" diseases as authorized medications claim. The time it takes to apply therapy varies from 20 to 90 minutes, depending on the person's location in relation to the equator.
Alnico magnets were invented in the 1920s and are the product of the combination of aluminum, nickel and cobalt. They last as long as neodymium magnets and are used today in high-temperature applications, applications requiring low coercitivity, mass production instruments and legacy applications in which the material has been designed.
In fact, alnico magnets, for many years, were the strongest permanent magnets available until rare earth magnets developed, so before the appearance of neodymium magnets, for example, alnico magnets ruled the world.
While eclipsed and largely replaced by these stronger rare earth magnets, alnico magnets are still commonly used in various industries for specific jobs such as high temperature control equipment and sensor manufacturing, to name a few.
They have been displaced because in most applications, alnico is much less powerful than neodymium magnets. Alnico magnets are manufactured by casting or sintering, i.e. they are molded, so they have the advantage of being made in quite complex shapes, such as a 4-pole round horseshoe magnet.
The durability of alnico magnets is precisely one of the reasons why they are still used today. In addition, it has important benefits such as:
Excellent temperature stability up to 537°C. 90% of the magnetization at room temperature is maintained up to this temperature.
High residual induction. Alnico magnets can produce powerful fields in certain configurations.
Alnico material does not corrode.
Fused alnico magnets can be produced in relatively complex shapes.
The tooling for molten magnets is relatively low, as sand moulds are generally used for the casting process.
But as we have mentioned before, alnico magnets are not the most commonly used in the modern era, precisely because, beyond their duration, they have some handicap that leaves them behind rare earth magnets, such as:
Alnico materials have a low coercitivity, so they are easily demagnetized.
They are relatively expensive, as they contain nickel and cobalt.
Fused alnicos often have pores and cast holes inside them, which can be problematic from an aesthetic point of view, and because large voids can decrease the expected magnetic flux.
Density: 0.265 lbs. per cubic inch
Required saturation magnetization field: around 5kOe.
Manufacturing methods: casting (most common), or sintering.
They are available in blocks, bars, discs, rings, horseshoes, etc.
They are available in grades from approximately 0105 to 0519. (The first 2 digits represent BHmax, and the other two digits represent Intrinsic Coercivity, or Hci).
Sizes: Outside of the tool, very large alnico magnets can be molded (horseshoe magnets weighing 225 kilos); smaller magnets are usually sintered (sintered disks, 1/16" in diameter).
Although special care must be taken to ensure that alnico magnets are not subjected to adverse repulsion fields, as these could partially demagnetize the magnets, they can certainly be easily re-magnetized as they are partially demagnetized by their coercitivity (the ability to demagnetize and re-magnetize easily).
At IMA we have a wide variety of alnico magnets and help you choose the right model for your needs. If you have any doubt, ask us.
Due to their ability to generate very powerful magnetic fields, low resistance and high efficiency, electromagnets have often been applied in medicine and scientific equipment. This sector has experienced significant growth in recent years.
This is why, today, electromagnets in medicine play a key role in advanced treatments, such as hyperthermia treatments for cancer, implants and magnetic resonance imaging, to mention just three of the areas of greatest use.
But beyond all the applications of electromagnets in medicine, the most important use of these in hospitals is in magnetic resonance imaging, commonly known as MRI.
It is used to get a detailed picture of the inside of the body, which helps diagnose a number of diseases. MRI can be used to diagnose brain tumors, hemorrhage, nerve injury, and stroke injury and can also detect if the heart or lungs are damaged.
In fact, studies have found that if the device generated static magnetic fields of 300 to 500 Gauss over a pain activation point, the application of the electromagnet provided immediate relief to the subjects.
This involves placing a powerful electromagnet in the patient's head and the electromagnet passes a current through the scalp to the underlying neurons. Patients treated with this have shown improvement with respect to depression, mania, Parkinson's disease and such disorders.
Magnetic resonance imaging (MRI) is now considered a diagnostic tool with high potential, but more studies are needed before its safety can be guaranteed.
Today there are countless uses for electromagnets, such as the application of electromagnets in industrial robotics, which is closely linked to medicine.
Electromagnets integrate median and robotics using the tools of a surgeon, such as an eye surgeon, who can extract steel pieces from a patient's eye with an electromagnet, increasing the current until he pulls enough to gently remove the metal.
Also, in microsurgery researchers are working on electromagnets that can move micro-robots around the body to perform the surgery without opening the patient.
Electromagnets are devices that work because an electric current produces a magnetic field, and if a wire carrying an electric current is formed in a series of loops, the magnetic field can concentrate inside the loops.
But if you want to know more about them, at IMA we can make it clear why electromagnets heat up, as well as help you choose the type of magnet that best suits your needs. If you have any questions, ask us.
When the magnetic poles of a metallic object are aligned in the same direction, magnetism is produced. We say that demagnetization occurs when there is a change or some kind of disorder in the magnetic poles. That can happen for several reasons, now we tell you about them, just as we tell you about the existence of tools that allow us to magnetize or demagnetize in a matter of seconds.
Materials are demagnetized when the magnetic molecules inside a substance are randomly assigned, causing disorder inside the previously aligned magnetic material.
Among the many ways we can see to demagnetize a magnet we propose the following because they are the most common.
You can heat a magnet to the Curie point. The process can be done with two copper wires that you have connected to a generator or a battery. You can also help yourself with a torch. At the Curie point the temperature reached causes the ferromagnetic properties to be lost until it cools down again. The energy we have applied to the magnetic poles will make the magnet point in different directions, so the poles will be deformed.
It is also possible to demagnetize a magnet by hitting the ends of the magnet with a hammer, which will alter the order of the magnet. To hit a magnet with an object in general, applying force, is a good mechanism to achieve this objective.
In the same way you can also use an alternating current field to alter the order of the magnetic poles. You can do this by connecting the magnet to an alternating current circuit by inserting it into a solenoid: a loop of coiled copper wire surrounding a metal core and connected to an electric current.
There are also simpler methods, such as rubbing two magnets together, which can also, in some cases, demagnetize.
Possibly, heating a piece of magnetized metal with a flame will generate demagnetization, destroying the order of the molecules inside the magnet. When a magnet is heated, each molecule is smeared with energy. This forces it to change and move, removing each molecule from the order it had inside the magnet and stripping the metal piece of its magnetization or leaving it with very little. This method is possibly one of the most used and the one that provides the best results.
In the same way, when a magnet is hammered or forged, the vibrations we are attempting by the impact on the magnet, generates the randomization of the magnetic molecules within it, breaking the order of the magnet. The more brute force we apply to it, the better results we will obtain.
We can also use alternating current, since it is capable of producing a magnetic field that can be moved and reduced to demagnetize materials. When we use the electric current and create this field, we carry the magnetic molecules of the magnet in different directions than they had previously. During the process, when the alternating current is altered or reduced, not all the molecules inside the magnet return to their previous positions, which causes the randomization of the molecules and the reduction of the force of the magnet.
Today there are many simple and inexpensive tools that work for magnetizing and also for demagnetizing. They are used to magnetize or demagnetize tools such as screwdriver tips. It is a process that only takes a few seconds and very simple, so it allows the work to be done in just a few seconds.
In industrial applications, choosing the type of magnet has important implications for motor design, project costs and overall performance. Therefore, it is important to know that, before making any decision, knowing why neodymium magnets in a motor may be the right choice.
To determine the use of neodymium magnets in a motor it is necessary to understand the qualities that distinguish magnets and their possible applications:
Remanence: the magnetic force of the material.
Energy product: the maximum amount of magnetic energy that can be delivered at maximum efficiency.
Intrinsic Coercivity - The resistance of the material to demagnetization, essentially a measure of stability as the temperature increases.
Curie Temperature - The temperature at which the magnetic properties of a material become ineffective.
Having clarified that point, it should be noted that of the four main types of magnets, neodymium magnets are among the most used in engines for hybrid and electric vehicles. Neodymium magnets have a higher remanence, along with higher coercitivity and energy production, but often a lower Curie temperature than other types.
Special alloys have been developed in neodymium magnets in an engine that include terbium and dysprosium with a higher Curie temperature, allowing them to tolerate temperatures up to 200 ° C. Because of this, no other magnetic material can match their high-strength performance, so their application in vehicles, for example, has increased considerably.
Neodymium magnets are the strongest magnets in the world. Due to their strength, even small magnets can be effective and this also makes them incredibly versatile. This type of magnet has been used for many purposes and without it many of the advances in the last 30 years would not have been possible.
The use of neodymium magnets in a motor, in this case electric motors, depends on a combination of an electromagnet and a permanent magnet, usually a neodymium magnet to convert electrical energy into mechanical energy.
The use of neodymium magnets in a motor is one of the most promising applications, because they include the latest electric and hybrid vehicles, which are often based on rare earth magnets. There are some special reasons available for people to use neodymium magnets instead of other types of magnets such as ceramic permanent magnets and ferrite.
When it comes to industrial applications, almost all are looking for higher performance with maximum efficiency. For example, when we take electric vehicles, a lightweight, high-performance engine reduces the amount of energy that needs to be transported in the form of hydrogen, gasoline, or batteries.
The development of neodymium magnets has given life to a great future for companies that dominate the automotive industry, such as one of Japan's leading manufacturers, which in its latest models has used 30 kilograms of rare earth materials and neodymium magnets have acquired a large percentage.
Motors containing neodymium magnets offer high performance compared to a traditional motor of the same size. They are therefore also used in wind turbines and generators, in which long-term efficiency is essential.
Neodymium magnets are small, but have become an important part of motors. These magnets were discovered in 1982, thanks to a joint effort by General Motors, China Academy of Science and Smitomo Special Metals who were looking for a suitable method to increase motor efficiency and effectiveness.
Neodymium magnets were developed in response to expensive samarium cobalt magnets. At this time, neodymium is considered to be the cheapest and strongest of the earth magnets as a result of these efforts.
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