Permanent Magnets-An Ultimate Guide

If you are looking for any information about permanent magnets, you will find the information right here.

Whether you want to learn about the properties, material, manufacturing process or classification criteria – this guide explores everything about permanent magnets.

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What is a Permanent Magnet?

Permanent magnets are objects that in addition to exhibiting magnetic capabilities persistently retain these capabilities even in the absence of external magnetic fields. This is facilitated by the arrangement of magnetic domains within the magnet.

Permanent magnet
Permanent magnet

How Permanent Magnets Work

We take a look at the main principles employed by permanent magnets and how they maintain their magnetic properties.

Permanent Magnet Work Illustration
Permanent Magnet Work Illustration

Atomic Structure and Electron Spin

At the heart of a permanent magnet lies atoms and subatomic structures consisting of protons, neutrons, and electrons. The protons and neutrons are held in the atom’s nucleus and they are orbited by electrons, which have an angular momentum. This momentum often leads to spinning, which generates a magnetic moment. And since permanent magnets are made of unique materials like cobalt and iron, the alignment of numerous moments leads to comprehensive magnetic moments.

Atomic Structure and Electron Spin
Atomic Structure and Electron Spin

Domain Formation

After the attainment of net magnetic moments within the magnet’s atoms, microscopic regions are formed. These regions are referred to as magnetic domains and they are essentially an assembly of tons of atoms with affiliated magnetic moments. In permanent magnets, these moments are aligned in a harmonious direction.

Magnetic Domain Formation
Magnetic Domain Formation

Generation of a Magnetic Field

With the magnetic domains in place and the magnetic moments aligned, a magnetic field is created.  The field covers the area surrounding the permanent magnet and its strength is determined by the magnetic material and the level of domain alignment.

Magnetic Field Generation on a Coil Spring
Magnetic Field Generation on a Coil Spring

Interaction with Other Objects

Magnets in general, typically interact with other items in two ways; attraction or repulsion. With the magnetic field functional, bringing a ferromagnetic object nearby will result in instant attraction. However, bringing diamagnetic objects within the magnetic field will result in immediate repulsion.

Interactions of Magnetic Poles
Interactions of Magnetic Poles

What is an Electro-Permanent Magnet?

Often abbreviated as EPM, an electro-permanent magnet is a distinct magnetic object that relies on an electrical control system to turn on and off its magnetic state. The magnet exhibits numerous properties which are synonymous with electromagnets as well as permanent magnets. For a clearer understanding, here is a sneak peek of its working principles:

Electropermanent Magnet
Electro permanent Magnet

Initial Magnetization

At the core of an electro-permanent magnet is a permanent magnet with robust magnetic capabilities. And just like a typical permanent magnet, this magnet contains specially aligned magnetic domains, which facilitate non-stop operation.

Activation

Electro-permanent magnets are differentiated from permanent magnets by their distinct ability to activate or deactivate functionality. This is usually accomplished using an electrical pulse that turns off or on the magnet’s functioning. Activation occurs when the aligned magnetic domains are disrupted temporarily.

Deactivation

This process is also referred to as neutralization and involves regulating the electrical pulse on the wire surrounding the permanent magnet. Permanent magnets, however, exhibit hysteresis behavior meaning that they can still demonstrate magnetic abilities despite the absence of electrical energy.

Advantages of Permanent Magnets

Permanent magnets are tremendously exploited and revered in various industries thanks to their unique capabilities. Here are some of their most astounding rewards.

Permanency

Just like their name suggests, permanent magnets are capable of continually serving you diligently. This is because they do not necessitate electrical energy to preserve their magnetic properties. For instance, if your refrigerator is equipped with a permanent magnet, you can rest assured that all your essentials will be preserved properly and efficiently.

Energy Efficient

One key feature of permanent magnets is their independence or lack of reliance on external electrical supply. They hardly demand electricity to exhibit or retain their magnetization mojo. This translates into lower power bills as well as numerous rewards to the ecosystem.

Compact

To operate in applications that necessitate stronger magnetic properties, one does not necessarily need a relatively large permanent magnet. This is because permanent magnets are capable of generating robust magnetic fields irrespective of size. This property makes them pivotal for applications with limited spaces. For instance, they are broadly employed in medical apparatuses and electronic equipment due to their compactness.

Cost-Effectiveness

Irrespective of the operation, cost is often a major concern for many. However, with a permanent magnet, you do not have to be overly concerned about the overall cost implications. This is because these magnets are specially designed to guarantee operational efficiency, which often translates into overall cost-efficiency in the long run.

High Magnetic Power

Permanent magnets are predominantly engineered to demonstrate robust magnetic capacities. Whether it is attraction or repulsion, you can trust a permanent magnet to do the work competently. This is particularly important for applications that deem strong magnetic properties as an absolute component. For example, generators and motors.

Sustainability

In a bid to fend off the adverse effects of climate change, the world is continually embracing sustainable technologies. Permanent magnets are considerable contributors to sustainability and their application to facilitate sustainability ranges from electric vehicles to electric motors. They help minimize carbon emissions by shrinking fossil fuel dependence.

Zero Electromagnetic Interference

Electromagnets are often susceptible to electromagnetic interference (EMI) unlike permanent magnets. This makes permanent magnets ideal for use in sensitive equipment such as medical equipment.

Versatility

Owing to their zero electromagnetic interference, robust magnetic power, compactness, and sustainability among other benefits, permanent magnets come in handy in multiple areas. Their application range spans from wind turbines to medical devices. Additionally, they are receptive to customization, which makes their application range virtually limitless.

Disadvantages of Permanent Magnets

Permanent magnets have undoubtedly had a profound implication on a multitude of devices and applications. However, despite all of their weighty advantages, they have exhibited some limitations. Thankfully, these limitations are not weighty and are far outweighed by their rewards.

Slacking Strength over Time

We have established that permanent magnets are well-regarded and characterized by their durability. However, this does not mean that they retain their optimal magnetic properties in perpetuity. After continued use, permanent magnets can suffer a condition often referred to as magnetic decay.

This phenomenon is typically occasioned by mechanical stress and extremely hot temperatures. This can be exemplified by the permanent magnets found in speakers. Owing to the constant exposure to heat, the magnets may lose their magnetic strength leading to the subsequent weakening of the speaker’s sound quality.

Limited Temperature Tolerance

High temperatures often tend to interfere with magnetic fields and this can greatly impact the power of a permanent magnet. Additionally, some of the materials employed in manufacturing permanent magnets weaken when exposed to hot temperatures resulting in reduced effectiveness.

For instance, an electric motor employed in an industrial setting can demonstrate lesser efficiency due to the wearing out of the inherent permanent magnets caused by excessive heat.

Fragility

When exposed to great or moderate physical pressure, most permanent magnets tend to break or chip. This is primarily because they are often made using brittle materials like neodymium.

This drawback limits their use in devices or settings with substantial vibrations such as heavy machinery. Furthermore, equipment with permanent magnets must be handled with care to avert breakages that may result in expensive repairs.

Disposal Difficulties

Despite being extremely durable, once a permanent magnet breaks or reaches its optimal life cycle, disposal can prove to be a bit of a headache. This is because the magnets contain harmful materials, which if improperly discarded can cause harm to an ecosystem as well as its inhabitants.

Furthermore, owing to the unique nature of the materials used to make the magnets, their recycling can also pose a serious problem. However, one can practice safe and recommended disposal practices to minimize the environmental pollution threat posed.

Electromagnet Vs Permanent Magnets

An electromagnet is a specialized object made up of magnetic material with an overlying wire responsible for conveying an electric pulse to magnetize the object.

As opposed to permanent magnets, which can be functional even in the absence of electricity, electromagnets have their magnetism limited. Underneath, we dissect these two distinct types of magnets with a view of bolstering your understanding.

Electro Magnets
Electro Magnets

Magnetic Field Generation

Electromagnets generally create an electromagnetic field by passing direct current over a magnetic core. This magnetic field can be activated and deactivated easily by switching on or off the electric pulse.

Permanent magnets, on the contrary, function by utilizing a natural magnetic field availed to them by the alignment of their magnetic spheres.  This magnetic field cannot be turned on and off at will.

Magnetic Strength Control

One can easily regulate the power of an electromagnet’s electric field by raising or lowering the amount of current on the surrounding wire. Shrinking the electric pulse on the coil would result in a less robust magnetic field while amplifying the current would result in a more robust field.

As for permanent magnets, their strength is largely constant and can only be determined by the construction material. They are quite difficult to modify after production and this makes their application fields, somehow limited.

Permanence

Electromagnets principally depend on electric pulses to generate magnetic fields. These fields can be switched off, making electromagnets perfect for impermanent applications. They are, however, not well suited for permanent applications or applications that necessitate energy efficiency.

Permanent magnets, on the other hand, are self-sufficient. They rarely require external backing to create a magnetic field. As such, they are extremely long-lasting and can be employed in settings that necessitate constant and robust magnetic fields.

Energy Consumption

As the name implies, electromagnets are energy-reliant. This means that they necessitate a form of electric energy to function and this can increase power bills.

In contrast, permanent magnets create and retain a magnetic field all on their own. They hardly consume any power and this makes them a flawless fit for energy-intensive applications determined to economize on energy use.

Applications

Owing to their unique features, electromagnets are better utilized in certain applications. For example, in electromagnetic brakes, solenoids, electric motors, and MRI machines.

Permanent magnets on the contrary are broadly exploited in loudspeakers, generators, refrigerators, motors, and hard drives.

Permanent Magnets
Permanent Magnets

Differences Between Permanent and Temporary Magnets

Permanent and temporary magnets are the two dominant magnet types currently in use today. However, these two varieties demonstrate a series of distinctions ranging from service life to composition and primary applications.

Here is an outlook of the key differences between temporary magnets and permanent magnets.

Permanent Magnets Temporary Magnets
In permanent magnets, the magnetic properties are inbound.

That is, individual magnetic domains align uniquely to generate long-lasting magnetic fields.

In temporary magnets, it is impossible to create a magnetic field self-sufficiently.

An external magnetic field must be employed to awaken the magnetic properties of the temporary magnet.

Magnetizing a permanent magnet can only be accomplished at the point of manufacturing. This is done using stronger permanent magnets or more powerful external magnetic fields. Temporary magnets can be magnetized anywhere and anytime as long as there is an external magnetic field.

Extraction of the foreign magnetic field results in demagnetization.

Once a permanent magnet is magnetized, loss of the magnetic properties is improbable. Temporary magnets can gain, lose and regain magnetism depending on exposure to external magnetic fields.
The atoms in a permanent magnet are arranged in a uniform direction. The atoms in a temporary magnet only align when there is a powerful magnetic field within.
Permanent magnets are stable and durable. As such, they are employed in applications that value longevity such as electronics and audio speakers. Temporary magnets are tailor-made for applications that need magnetic fields momentarily such as electromagnets.

 

Types of Permanent Magnets

Owing to an abundance of use scenarios and devices reliant on permanent magnets, manufacturers have diversified their production lines.

At present, the magnets market is flooded with tens of distinct permanent magnets differentiated by manufacturing material, magnetic strength, and shape. Here is a brief explanation of the various kinds of permanent magnets, the current market has to offer.

Neodymium Permanent Magnets

Neodymium permanent magnets are characterized and renowned for their robustness in magnetic strength. As such, they have established themselves as some of the world’s leading permanent magnets resulting in extremely high commercial and industrial application ratios. Their make-up includes iron and boron in addition to neodymium. They are perfect for industrial applications that demand exceptionally strong magnetic properties.

Neodymium Permanent Magnet
Neodymium Permanent Magnet

SmCo Permanent Magnets

When expanded, SmCo magnets stands for samarium cobalt and this is a material commonly utilized to manufacture permanent magnets. The use of these materials to manufacture permanent magnets results in exceptional magnets capable of withstanding hot temperatures. The magnets are also corrosion tolerant hence they are broadly employed in aerospace applications. They are further divided into SmCo5 and SmCo17.

SmCo Permanent Magnet
SmCo Permanent Magnet

Ferrite Permanent Magnets

Ferrite magnets are differentiated from other magnet types by their composition; iron oxide. They are also referred to as ceramic magnets and some of their core strengths include extreme power and excellent durability.

For this reason, they are widely utilized in loudspeakers. They are equally cost-friendly and their durability translates into consistently good quality audio. Ferrite magnets come in two variations, namely;

Ferrite Permanent Magnets
Ferrite Permanent Magnets

Strontium Ferrite Magnets

They go by the name strontium ferrite permanent magnets because strontium carbonate is the main ingredient used to manufacture them. They however include iron oxide, which makes them relatively pocket friendly. All though their magnetic power is lower compared to other permanent magnets, they are resistant to demagnetization.

Barium Ferrite Magnets

Instead of utilizing strontium carbonate, these permanent magnets incorporate barium carbonate besides iron oxide. As such, they tend to outwit strontium ferrite magnets when it comes to magnetic strength as well as reliability. For this reason, they are highly sought after in applications that are marred by high temperatures such as microwave devices and electric motors.

Alnico Permanent Magnets

Alnico is a prominent material for manufacturing alnico magnets and the name is essentially an abbreviation for aluminum, nickel, and cobalt. These substances are often accompanied by other elements such as iron. Alnico permanent magnets are available in varied shapes and they are born into life thanks to sintering or casting procedures. They are characterized by high thermal stability and this sees them widely utilized in high-temperature applications.

AINiCo Permanent Magnet
AINiCo Permanent Magnet

Flexible Magnets

Flexible magnets are more appreciative of unique shapes and they can be easily twisted and turned. They are manufactured by combining the typical magnet-construction material like neodymium with polymer binders. The end result is a flexible substance that can be used to generate signage magnets and flexible magnet strips.

Flexible Magnets
Flexible Magnets

Shape-Based Permanent Magnets

In addition to being categorized according to respective construction materials, permanent magnets are also classified based on their corresponding shapes. Beneath, we take a look at some of the most renowned shape variations of permanent magnets.

Bar Magnets

Bar magnets are without a doubt the most common and identifiable permanent magnet shape. They are rectangular in shape and this gives them a look similar to that of a bar hence the name bar magnets. At each end of the bar lies an opposite pole (North and South) and this allows them to create strong magnetic fields.

Bar Magnets
Bar Magnets

Cylindrical Magnets

Cylindrical permanent magnets exhibit a cylindrical cross-section and are characteristically compact. This chimes well with applications such as sensors and motors, which demand strong magnetic properties as well as small sizes.

Cylindrical Magnets
Cylindrical Magnets

Ring Magnets

Ring magnets resemble a circular shape with a hole at the center, just like a typical ring. For this reason, they are also likened to doughnuts and they generate a magnetic field across the hole at the center. Ring magnets are often used in audio speakers.

Ring Magnet
Ring Magnet

Irregular-Shape Magnets

In addition to the classical-shaped permanent magnets, there are also irregularly shaped magnets. These magnets are manufactured in custom shapes making them ideal for exactly what you need them for. They are common entities in electronics and specialized devices.

Irregular Shape Magnet
Irregular Shape Magnet

Characteristics of Permanent Magnets

Permanent magnets play vital roles in our daily lives and most of the time we do not even recognize their presence. They are able to carry out their assigned roles thanks to the unique physical attributes discussed underneath.

Magnetic Field

A magnetic field refers to the area under the magnetic influence of a specific magnet. Within this field, magnetic forces come into play resulting in attraction or repulsion. Permanent magnets initiate electron spins independently leading to the formation of a magnetic field. Although the strength of the formulated magnetic field may vary, it can be measured and the standard measurement unit is Tesla.

Magnetic Field
Magnetic Field

Magnetic Domains

A magnetic domain is an area on the magnetic object responsible for synchronizing magnetic moments. This aligns these moments in a harmonious direction and a single magnetic material can have more than one magnetic domain.

Magnetic Domains
Magnetic Domains

Ferromagnetic Material

Permanent magnets are predominantly constructed using ferromagnetic material and this is the phenomenon behind their functionality. Notable examples of ferromagnetic materials include iron and cobalt. In these materials, electron spin is initiated naturally resulting in the spontaneous alignment of magnetic moments.

Ferromagnetic Materials
Ferromagnetic Materials

Anisotropy

Permanent magnets exhibit anisotropy rather than isotropy. This is an attribute that makes the magnet directionally dependent and this property helps manufacturers tailor the magnet’s behavior to its intended application.

Magnetic Anistropy
Magnetic Anistropy

B-H curve (Hysteresis Loop)

The B-H curve is ideally a pointer that indicates the subsequent changes in magnetic flux density once there is a change in the magnetic force. It can also be referred to as the hysteresis loop.

The magnetic flux density is represented by the (B) while the (H) represents the magnetic force. An upsurge in the force, sees the magnetic field get stronger, but it takes time to get as strong as it can be. And a decrease in the force sees the magnetic field weaken but it does not weaken immediately. This lag is what is known as the hysteresis loop.

Hysteresis Loop
Hysteresis Loop

Curie Temperature

A curie temperature is a temperature threshold that when contravened sees the permanent magnet drop its permanent magnetism. This is possible because high temperatures are capable of disrupting the alignment of magnetic moments and a common consequence of this is the loss of magnetic properties.

However, it is essential to note that the curie temperature of a permanent magnet is determined by the manufacturing material.

Curie Temperature in Magnetism
Curie Temperature in Magnetism

Coercivity

Coercivity is an attribute commonly associated with permanent magnets. This property is an indication of the magnet’s ability to hold on to its magnetism or its reluctance to accept the loss of magnetic properties.

Permanent magnets are also known for exhibiting remanence properties. This property showcases their potential to withhold a robust magnetic field even after the removal of a peripheral magnetic field.

Coercivity in Magnetism
Coercivity in Magnetism

Determining the Strength of Permanent Magnets

To ensure your permanent magnet accomplishes its set assignment, it is important that you measure its strength to ascertain if it is up to the task. The power of a magnet can be determined using a number of verified and extremely precise techniques. Here is a breakdown of the three most utilized parameters for measuring magnet strength.

Gauss Meter

A Gauss meter is primarily employed in scenarios where the goal is to establish the strength of a magnetic field at a specific point neighboring the magnet’s surface.

This is also referred to as the flux density measurement and the apparatus used relies on a Hall sensor to detect the power of the magnetic field. To use a Gauss meter, simply place it closer to the magnet and the magnetic strength will be portrayed in Gauss or Tesla units.

Magnetometer

Unlike a Gauss meter, the magnetometer seeks to compute the overall strength of a permanent magnet. It measures the comprehensive magnetic moments of your magnet by computing the magnetic field strength as well as assessing the magnet’s physical dimensions.

To use a magnetometer, you must first suspend your magnet to quantify the force experienced within the magnetic field. This technique provides a more comprehensive view of the magnet’s strength.

Pull Tester

A pull tester is mainly utilized to gauge the ability of a magnet to attract or repel magnetic items as well as its adhesive strength. To use a pull tester, simply place one pole of your permanent magnet on the tester and the opposite pole on another magnet or magnetic object.

 

The pull tester will initiate detachment between the magnet and the other object. The results provided will highlight the magnet’s strength in terms of its ability to hold onto or pull other objects.

Factors That May Affect the Strength of a Permanent Magnet

The strength of a permanent magnet determines its suitability for specific applications. However, during use fluctuations of the magnet’s strength may be recorded owing to a number of factors as explained underneath.

In fact, there are a number of factors that determine how long a magnet lasts.

Magnetic Material

The material used to manufacture a magnet is without a doubt the most telling feature of a magnet’s strength.

Permanent magnets are manufactured using robust materials such as neodymium and this equips them with stronger magnetic powers.

Quite often, they are composed of numerous elements, which combine to generate distinct atomic alignments, and this results in higher magnetic strengths.

Temperature

Temperature variations can have adverse implications on a permanent magnet. Hot temperatures can especially cause a permanent magnet to lose its magnetism by disrupting the magnetic domain alignments.

All magnets have a curie magnet temperature and the breaching of this point results in reduced magnetic strength.

Impurities and Defects

The accumulation of dirt and other foreign substances on the magnet can also impact the magnetic strength. Similarly, defects and breakages can impede the arrangement of magnetic domains resulting in weaker magnetic forces.

External Magnetic Fields

It is paramount that one carefully considers the surrounding environment because external magnetic fields can greatly impact the performance of one’s magnet.

We have seen that powerful external magnetic fields can empower objects with magnetic properties but the presence of an opposing field can lead to demagnetization.

Magnetic Domains

As mentioned earlier, the magnetic capabilities of permanent magnets are primarily determined by the alignment of the magnetic domains.

More organized alignment resulting from strong external fields translates into more robust magnets while disruptions to these arrangements can cause magnetic strength loss.

Best Permanent Magnet Materials

Permanent magnets have one thing in common; they are extremely durable. However, they exhibit various differences key amongst them being their composition.

Their composition greatly influences their performance hence why we are going to discuss the 5 best materials known for manufacturing permanent magnets below.

· Ferrite (Ceramic)

Ferrite or ceramic is one of the most common materials for manufacturing exemplary permanent magnets. The ferrite used to make magnets sees iron oxide blended with either barium or strontium to create a magnetic compound that is resistant to corrosion.

Despite ceramic exhibiting comparatively inferior magnetic strength, it guarantees stability at high temperatures. It is relatively inexpensive and ceramic magnets come in handy in applications such as automotive and microwave components.

· Neodymium

This is a rare-earth material renowned for manufacturing some of the best permanent magnets. At the core of neodymium magnets lies an alloy made of iron, boron, and neodymium.

Magnets made of neodymium exhibit the strongest magnetic capabilities but their use is limited to temperatures below 300°F. They are also vulnerable to corrosion but their unmatched strength makes them suitable for use in medical equipment and loudspeakers.

· Alnico

Permanent magnets made from Alnico demonstrate high curie temperature (up to 1000 °F) and moderate strength when it comes to magnetic properties.

Alnico is essentially a blend of distinct elements, key amongst them being aluminum, nickel, and cobalt. Owing to the unique features of Alnico, magnets made using this material are widely deployed in high-temperature applications.

· Samarium Cobalt

Combining samarium and cobalt as well as other elements creates a magnetic material with high corrosion resistance.

The material is characteristically brittle but it can withstand temperatures not exceeding 500°F. Their primary uses include defense systems and other high-temperature applications.

· Flexible Material

Flexible materials generated by mixing magnetic powder with flexible binders like vinyl are also popular materials for manufacturing magnets.

However, the resulting magnets exhibit slightly inferior magnetic properties. The point of manufacturing flexible magnets is to open up customization opportunities. These magnets are popularly used in promotional signage and refrigerators among other uses.

How to Make Permanent Magnets

The process of manufacturing permanent magnets, especially at an industrial level can be demanding but with the right technology and proficiency, great results are guaranteed.

Ideally, the process can take up to 6 weeks and this underscores the intricacy of the processes involved. Below is a comprehensive breakdown of the stages and processes undertaken to create permanent magnets.

 

Selection and Preparation of the Raw Materials

To begin the magnet manufacturing journey, the requisite materials are amassed and prepared to ensure they meet production standards. The primary raw materials for permanent magnets are principally rare-earth magnet materials like cobalt and neodymium.

They can be acquired through mining before being transported to a manufacturing facility. In the facility, they are processed to ensure that they meet purity and composition standards.

Powder Mixing

The processed raw materials are often in powder form. They are then mixed rigorously with special attention paid to the composition and portions. Predetermined ratios are referred to during the mixing process and this is critical as any miscalculations could lead to low-quality permanent magnets.

Compaction (Pressing)

The perfectly blended powder is then compacted using high-level mechanical compactors. Hydraulic presses often offer a suitable alternative.

During this process, magnetic properties are embedded in the compacted material. This is accomplished by transmitting electrical current through the pressed mold. During compaction, the powdered mixture is also pressed intensely to assume a desirable shape and size.

Sintering

The compacted substance drawn from the previous stage is subsequently undertaken through the sintering process. This process equips the substance with magnetic properties and it involves subjecting the substance to high temperatures (over 1200°C). During this process, a dense and solid material is produced since the powdered mixture is fused together. Sintering must be performed in a controlled atmosphere.

Magnetization

Although the product drawn from the sintering process has been equipped with magnetic properties, the state of magnetization is considerably low.

Therefore, the material is exposed to powerful magnetic fields, which align its magnetic domains in a uniform direction. This results in a substance with profound magnetic strength and capabilities.

Cutting and Shaping

Here, the magnetized material is cut and designed into shapes that reflect its final form. Permanent magnets can assume various shapes depending on their intended use.

Some of the most prominent permanent magnet shapes at present are bar, ring, cylindrical, and strip magnet shapes. For precision, elite-level cutting methods are employed. They include laser cutting as well as diamond sawing.

Surface Treatment

Finally, the magnets are subjected to several post-treatment practices such as cleaning and coating. These practices are designed to augment the magnet’s longevity, avert breakages and enhance its corrosion resistance.

Typically, nickel epoxy is utilized to coat permanent magnets but other materials can also be used. Surface treatment is essential as it also gives the magnets a smooth finish.

Quality Control

Quality control is a process that is undertaken throughout the entire manufacturing process. It involves testing the raw materials, measurement of magnetic properties installed, and dimension inspections among others.

It is a pivotal step that ensures all manufactured magnets are of the requisite standard and they meet the stipulated specifications.

Inspection and Packaging

In addition to quality control, a final inspection step is undertaken to make sure all the magnets are perfect. This is the double-checking phase and eliminates the probability of magnets with inferior quality, defects, and wrong specifications. After inspection and approval, the permanent magnets are packaged carefully, ready for storage or shipment.

Applications of Permanent Magnets

For many contemporary technologies and devices, permanent magnets are the foundation block.

Since their inception, magnets have found their way into our homes via refrigerators and other appliances, and into our industries via electric motors. Underneath, we focus our attention on the multitude of applications that are currently benefiting from permanent magnets.

  • Electric Motors: Electric motors are found in various equipment including car engines and they all feature permanent magnets, which generate rotational motion.
  • Generators: Generators are essentially tasked with drawing electricity from mechanical energy and this is often achieved with the aid of permanent magnets.
  • MRI Machines: Magnetic Resonance Imaging (MRI) machines employ high-quality magnets with zero electromagnetic interference to generate scans of internal body structures.
  • Loudspeakers: In audio equipment, permanent magnets ensure we experience quality sound by producing the requisite magnetic field need to generate sound.
  • Magnetic Separation: Permanent magnets are also vital tools in waste management seeing that they help alienate ferrous materials from non-ferrous materials.
  • Magnetic Bearings: Magnetic bearings are essential in rotating machinery seeking to avert friction. To create these bearings, permanent magnets are paramount.
  • Magnetic Locks: Advancement in technology has seen the inception of electromagnetic locks (maglocks), which secure doors through magnetic attraction. This is facilitated by permanent magnets.
  • Magnetic Stirrers: In modern laboratories, permanent magnets are used in magnetic stirrers to agitate liquids without the need for direct physical contact.
  • Magnetic Toys: Children’s toys fitted with permanent magnets tend to have more imaginative and interactive play experiences.

FAQs

Which is the Strongest Permanent Magnet?

Permanent magnets made of neodymium, which is a rare-earth material are at present the most robust magnets.

They have elite-level magnetic properties, can create robust magnetic fields, and are extremely long-lasting. They are followed closely by SmCo magnets, Alnico magnets, ceramic magnets, and finally flexible magnets, in that order.

Can Permanent Magnets Be Demagnetized?

Demagnetization is simply the opposite of magnetization and it refers to a phenomenon in which a magnet gets deprived of its magnetic capabilities.

Even though permanent magnets are exceedingly durable, subjecting them to certain conditions or processes can result in demagnetization.

Leading factors known for causing demagnetization or magnetic property loss include exposure to hot temperatures and reverse magnetization. Reverse magnetization involves the application of stronger magnetic fields but in a contrasting direction.

Do Permanent Magnets Last Forever?

When utilized in the right settings and subjected to the perfect conditions, permanent magnets can last for years and years to come.

It has been established that a well-taken-care-of permanent magnet retains 99% of its magnetic capabilities even after 100 years. However, exposure to extreme conditions such as temperatures beyond its curie point can greatly shrink its magnetic strength prematurely.

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