Ferrite Magnets, also known as ceramic magnets, are a suitable alternative to natural magnets. These magnets are used in electronic devices & industrial applications across the world. They are found in over 70% of all the products that require a magnet for smooth operation.
Two common reasons for their growing demand are cost-effectiveness and superior corrosion resistance to chemical substances, such as solvents, bleaches, and chlorhydric acid.
Ferrite Magnet Composition
The ferrite magnets are made with a combination of iron oxide and strontium carbonate or barium carbonate. These elements are heated at a temperature above 2000° F, which results in a chemical reaction that brings the formation of a ferrite material. This is why the magnets offer good resistance to demagnetization and carry high intrinsic coercivity.
In this article, we’re going to discuss ferrite magnets and important considerations to help you make the right choice for your industrial applications. Let’s get started.
Types of Ferrite Magnets
1. Soft Magnets
Soft ferrite magnets are ferrimagnetic in nature, as they can be magnetized or demagnetized easily. They are designed in the shape of a cubic crystal. These magnets are ideal for a range of applications, such as transformers, filters, radio cores & tape recorders.
They are produced in bulk, as they have a high output value. One of the properties that differentiate them from others is low coercivity.
2. Hard Magnets
Hard ferrite magnets have a high coercivity, which is why they are difficult to demagnetize. These magnets are not susceptible to change and have a permanent magnetic field.
3. Permanent Magnets
Permanent ferrite magnets are hard and powerful. They are designed in a uniaxial hexagonal shape. These magnets can keep their properties for a prolonged period and then use them to produce a magnetic field. Common uses of these magnets are microphones, refrigerators, automobile components, and wireless connections.
4. Spin Magnets
Spin magnets are made as per rotary magnetism, so they have two perpendicular magnetic fields and an electromagnetic wave field. Owing to this combination of different fields, there is a constant rotation of the magnet.
Although some of the metal magnets also have the spin magnetism property, but they have eddy current losses, which makes them unsustainable. This has contributed to the increasing use of ferrite or ceramic magnets.
5. Moment Magnets
Moment magnets are designed with rectangular hysteresis loops. When these magnets are in close proximity to a magnetic field, they get magnetized and saturated.
But the best part is that they remain magnetized even after the magnetic field is kept away. Produced with elements such as magnesium manganese and lithium manganese, these ferrite magnets are a major component used in the memory of desktops.
Major Benefits of Ferrite Magnets
Ferrite magnets are made with non-metallic materials, so they have a lower cost as compared to other magnets. Their production process is also easier, which is why they are preferred for electronic devices.
The usefulness of a magnet is determined by its magnetism retention when kept under stressful and harsh conditions. Although most of the magnets demagnetize when they face high temperatures and vibrations, ferrite magnets are more durable.
They retain their magnetism even in harshest conditions or higher temperatures. The magnets can handle electrical exposure, so they are ideal for DC motors.
3. Corrosion Resistance
Ferrite magnets are made with elements–iron oxide & strontium carbonate that are naturally corrosion resistant. This property or strength of the materials is transferred to the magnets, making them ideal for industrial environments.
These magnets can be magnetized easily in multiple directions. So, they are adaptable for a wide range of industrial applications.
5. Multiple Shapes
The ferrite magnets are produced using compact powdered material, so they can be transformed in any shape, size, or configuration as per the need. Owing to their size, they can be used in both small toys and heavy equipment.
Common Applications of Ferrite Magnets
You can use ferrite magnets for applications where powerful rare earth magnets, such as neodymium magnets & samarium cobalt magnets, do not fit in. Some of the common applications include:
- Security Systems
- Motors & Generators
- Lifting Magnets
- Pot Magnets
- Clamping Systems
- Overband Magnets
- Marine applications
- Eddy Current Devices
Popular Grades you can Consider for Ferrite Magnets
There are 27 grades of ferrite magnets that are available to customers. These grades have unique characteristics depending on their ferromagnetic properties. The grades begin with a letter, for example, “C” and then comes a number or a series of numbers along with it. These numbers show the maximum energy of the magnet for a product.
Here we are presenting some popular grades that you can easily find in the market for a range of your applications.
1. Grade C1
These magnets are small and weak, so they can be adjusted into tighter spaces. They are ideal for high-temperature applications as they are produced with an operating temperature of 249°C. Common uses are loudspeakers and motors.
2. Grade C5
These magnets are quite popular because of their magnetic properties. You can magnetize them toward their orientation. However, they can also be demagnetized so they are not suitable for all industry applications.
3. Grade C8
These magnets are reliable because of their high energy and resistance to demagnetization. They are usually preferred for applications that need a small magnet and need to control demagnetization.
Do ferrite magnets need coating?
Ferrite magnets are made with iron oxide, so they have great corrosion-resistant properties. They do not corrode when dipped in water (including salt water) and exposed to moisture or weak acids. They are also resistant to salts, gases, solvents, and lubricants. This characteristic makes them a popular choice for various applications.
As these magnets resist corrosion, they don’t need coating and last a long time even without it. Usually, these magnets last longer than the equipment they are used in.
In exceptional cases for applications, such as medical equipment, these magnets can be coated to keep away the dust and dirt and ensure the highest protection. In addition, they can be coated to hide their dark gray color and enhance them with a better one.
The coatings may be of-
How strong are ferrite magnets?
Ferrite magnets are known as permanent magnets because of their strength and durability. They are the strongest magnets out of all that exist on the globe. If you need to calculate the magnetic force of these magnets, you can use specific units of measurement and change them into an exorbitant amount.
Ferrite magnet strength
The strength of a ferrite magnet is estimated in a unit known as ‘Tesla’. The average strength of a magnet is around 0.35 Tesla.
Effects of Changing Temperature on Ferrite Magnets
Ferrite magnets change their behavior depending on the temperature. When these magnets are kept in higher temperatures, their resistance to demagnetization increases similar to their intrinsic coercivity. Therefore, they are in greater demand for applications that need higher operating temperatures like motors, generators & loudspeakers.
Ferrite magnet increases its intrinsic coercivity by 0.4% for each degree Celsius increase (from ambient) and decreases by 0.2% for each degree Celsius increase. These effects can be reversed if the operating temperature gets back to the ambient position.
Here, grades that have lower operating temperatures have to bear permanent demagnetization at higher temperatures. Hence, ferrite magnets can be used for up to 180 degrees Celsius, but they may not work efficiently in lower temperatures, especially below 0 degrees Celsius.
The magnet may show a decreased pull force depending on the size & shape of the magnet, along with the environment it is kept in. However, you note that if the design is appropriate, the ferrite magnet can work effectively in colder temperatures of as low as -35 degrees Celsius.
How are ferrite magnets manufactured?
Manufacturing ferrite magnets is a complex process in which the materials pass through several stages. It includes the following steps:
- First, the raw materials, like iron oxide, are milled into a fine powder.
- This powder is heated at 1000°C, which is known as the calcining process. It is combined with water and a binding agent. Then, it is again dried and turned into a powder.
- When the powder is dried, it is converted into the form of a magnet. But, it is not magnetic yet.
- Now, the ferrite magnet undergoes the sintering process. In this, the fine particles of the powder are combined by using heat.
- The magnet is grinded and polished and then magnetized.
- The entire process is repeated so that the magnetization is not dissipated.
- At last, your ferrite magnets are ready for processing on other levels.
Potential Dangers of using Ferrite Magnets
Ferrite magnets are extremely useful for various industries, but they also come with some potential dangers that may happen if you are not careful.
1. Breakage or Chipping
Magnets when placed together attract and jump, which is one reason for their breakage. These broken magnets are quite sharp, so they have to be handled with care to avoid cuts and injuries.
2. Fingers Crushing & Cuts
When larger-sized ferrite magnets are kept together, they have a surprising amount of power. When you are handling them, you need to be extra careful to avoid getting your fingers caught between them. Otherwise, this may lead to hurt, cuts, or injuries to your fingers & hands.
To prevent this, you can wear gloves every time you handle the magnets & keep yourself protected.
3. Harmful for Magnetically Sensitive Objects
There are magnetically sensitive objects at your home that are susceptible to magnetic power. You must keep them away from the magnets at a safe distance of about 20 cm. Some examples of these objects are television, mechanical watches, credit cards, videotapes, etc that can be damaged by magnetism.
4. Dangerous for Eyes
When there are two or more magnets in the same place, they exert greater force which also increases the possibility of chips flying off at high speed and hurting someone’s eye. Hence, while handling two or more ferrite magnets, you can wear a helmet for protection.
5. Dangerous for Children
While playing with ferrite magnets, children must be under adult supervision to ensure their safety. If they are likely to swallow the magnets, they should not be allowed to even touch them at any cost. This is because if it happens, the magnet can get stuck in their stomach while upsetting their digestive tract and causing swelling and life-threatening problems.
Larger magnets can also crush the fingers and bones of little children as they are very strong and heavy. So, keep them away from children to ensure their safety.
6. Affects the ability of Heart Pacemakers
Magnets are used to set the pacemakers in a way that they do not respond to a patient’s heart rhythm. They help to make changes in the pacemaker’s working and see how they operate.
But when these magnets are kept in close proximity to the pacemakers, they can affect their working. This may not be ideal for the health of the user. However, when the magnets are taken away, this problem is resolved.
Ferrite Magnets- Is it the Right Choice & How can I Buy it?
Ferrite magnets are the most durable and strong magnets. These magnets are made from a magnetic material that is of high quality and affordable. So, they are an ideal choice over other magnets in terms of strength and price.
One thing that differentiates them is their resistance to oxidation while maintaining their magnetic and physical properties for a longer time. Hence, you must prefer ferrite magnets over other natural magnets for your applications.
If you are looking to buy ferrite magnets for your business, you must find a reliable manufacturer and supplier to find the right product. One such trusted company where you can buy ferrite magnets of the highest quality and at the best prices is Cosmo Ferrites.
They manufacture ferrite magnets in a variety of shapes, sizes, and configurations. You can buy these magnets in small or large quantities as per your business needs. Their staff can help you find the right product to ease your selection process if you feel stuck.
Owing to their 36 years of experience in the wound component industry and in-house manufacturing, they are one of the most trusted companies for serving your industrial component requirements. So, what are you waiting for? Get connected to their customer support team now.