Alnico Magnet
What is Alnico Magnet
An Alnico magnet is a type of permanent magnet crafted from a blend of aluminum, nickel, iron, cobalt, and various other materials. These magnets can be found in isotropic, non-directional forms, or anisotropic, directional forms. After being magnetized, they possess a magnetic strength that is 5 to 17 times greater than that of magnetite or lodestone, which are naturally occurring magnetic substances known for attracting iron.
Benefits of Alnico Magnet
High Temperature Stability
One of the most significant advantages of alnico magnets is their ability to maintain magnetic properties at high temperatures. Alnico magnets can withstand temperatures of up to 500°C (930°F) without losing their magnetism, making them ideal for high-heat applications such as engines and turbines.
Resistance to Demagnetization
Alnico magnets have high resistance to demagnetization, meaning they can retain their magnetism even in challenging environments. This property is especially important in applications that experience high external magnetic fields, such as electrical motors.
Durability
Alnico magnets are known for their long-term durability, able to perform consistently over extended periods without significant loss of performance. Their robust construction ensures they can handle the wear and tear of industrial environments.
Customizability
Alnico magnets can be manufactured in a wide range of shapes and sizes. Whether cast or sintered, they can be tailored to meet the specific needs of different applications. This flexibility makes them highly adaptable to a variety of industries.
Alnico are that it is hard, brittle, has a low coercive force, excellent temperature stability, high residual induction and fairly high energies. More cost-effective than high-strength rare earth magnets and having higher magnetic force and permanence than ceramic magnets, alnico magnets are the perfect fit for a wide range of applications. For instance, cow magnets are made exclusively from alnico, and alnico magnets are also used in sound amplification, electric motors, sensors and many sorting and lifting tools.
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We believe that our company's success is directly related to the quality of the products we offer. They meet the highest quality standards as stipulated by ISO 9001, ISO 14000:14001, SGS guidelines, and our stringent quality control system.
Application
The company focuses on the research, development, and production of precast concrete magnets, fishing magnets, magnet hooks, and magnetic separators. Our products are widely used in precast concrete, food, medicine, chemicals, minerals, industrial filtration, recycling, and other industries.
Types of Alnico Magnets
Alnico magnets are most commonly available in grades 5 and 8, although other grades are available. Grade 5 cast alnico material is the most commonly used type of alnico material, and can be found in applications ranging from simple holding applications to complex rotating machinery. Grade 8 cast alnico has the highest temperature stability of any magnetic material currently available, and it boasts a 6.0 energy product combined with resistance to demagnetization. Grade 8 cast alnico can be found in motors, generators, computer components, transducers, and more.
Other types of alnicos are available as well, such as sintered alnico. Sintered alnico has slightly lower magnetic properties but significantly higher mechanical properties compared to cast alnico, and is used in applications that involve high-speed motion or require a shorter magnetic length. Sintered alnico can be manufactured to very close tolerances, and its fine grain structure means it has highly uniform mechanical strength and flux distribution. Sintered alnico is often used in applications such as sandwich-type holding assemblies, traveling wave tube stacks, torque transmitting devices, and reed switches.
7 Key Differences Between Alnico Magnets and Other Types of Magnets
Magnetic Strength Differences Between Alnico Magnets and Other Types of Magnets
Alnico magnets, composed of aluminum (Al), nickel (Ni), cobalt (Co), and iron (Fe), possess moderate magnetic strength compared to other permanent magnets.
Neodymium magnets, on the other hand, are known for their unparalleled magnetic strength, being the strongest commercially available magnets. Ferrite magnets, also known as ceramic magnets, lie on the lower end of the spectrum in terms of magnetic strength. Samarium cobalt magnets offer strong magnetic properties but are not as potent as neodymium magnets.
Temperature Stability Differences Between Alnico Magnets and Other Types of Magnets
Alnico magnets demonstrate remarkable temperature stability, retaining their magnetic properties even at elevated temperatures. This characteristic makes them suitable for applications where exposure to high temperatures is common, such as in industrial processes and certain electrical devices.
In contrast, neodymium magnets have poor temperature stability and may experience significant loss of magnetic strength at high temperatures. Ferrite and samarium cobalt magnets fall somewhere in between, exhibiting decent temperature resistance.
Corrosion Resistance Differences Between Alnico Magnets and Other Types of Magnets
Alnico magnets showcase good resistance to corrosion, thanks to their alloy composition. They can withstand mild atmospheric corrosion and are often utilized in outdoor applications.
Neodymium magnets, however, are highly susceptible to corrosion and require protective coatings to prevent degradation in humid or corrosive environments. Ferrite magnets boast excellent corrosion resistance and do not typically require additional protective coatings. Samarium cobalt magnets share good corrosion resistance properties with Alnico magnets.
Cost Differences Between Alnico Magnets and Other Types of Magnets
When it comes to cost, neodymium magnets are generally the most expensive among all permanent magnet types. Their high magnetic strength and the rare-earth materials used in their composition contribute to their higher price tag.
Alnico magnets are more affordable than neodymium magnets but costlier than ferrite magnets, which are the most economical option. Samarium cobalt magnets fall somewhere in the middle in terms of cost.
Applications Differences Between Alnico Magnets and Other Types of Magnets
Each magnet type finds its niche in specific applications based on its unique properties. Alnico magnets ‘temperature stability makes them ideal for use in temperature-critical applications like sensors, meters, and instruments. Their corrosion resistance and ability to withstand high temperatures make them well-suited for various industrial applications, including aerospace and automotive engineering.
Neodymium magnets, with their immense magnetic strength, are preferred in applications requiring compact and powerful magnets, such as high-performance motors, speakers, and medical devices. Ferrite magnets, due to their cost-effectiveness and good performance in lower-strength applications, are widely used in consumer electronics, toys, and other general-purpose devices. Samarium cobalt magnets are employed in high-temperature applications and where a balance between magnetic strength and temperature resistance is required.
Demagnetization Differences Between Alnico Magnets and Other Types of Magnets
Alnico magnets exhibit good resistance to demagnetization, making them durable and reliable in long-term use. They can withstand external demagnetizing fields better than some other magnet types.
Neodymium magnets are more susceptible to demagnetization, especially at high temperatures, and require careful handling and magnetization processes to minimize this effect. Ferrite and samarium cobalt magnets also demonstrate good resistance to demagnetization.
Shape and Size Differences Between Alnico Magnets and Other Types of Magnets
All magnet types can be manufactured in various shapes and sizes to suit specific application requirements. Alnico magnets are no exception and can be easily made into custom shapes. This flexibility allows them to fit into intricate designs and specialized devices.
However, neodymium magnets, being extremely strong for their size, often allow for more compact designs in certain applications.
Uses of Alnico Magnets
Motors
‘‘Alnico rotor magnets have multiple poles with alternating polarity. The hole in the rotor allows it to be mounted on a shaft. They are excellent for use in synchronous motors, dynamos, and air turbine generators.
Cow Magnets
‘‘Cow magnets are a tool to save the lives of cows, which eat grass, dirt, nails, staples, and bits of bailing wire. When iron items work their way through the stomachs of cows, they cause ‘ hardware disease’ , which threatens the cow’ s vital organs and causes irritation and inflammation. The magnet is inserted into the cow’ s mouth as a pill and lodges in the cow’ s second stomach to attract the stray metal.
Speakers
‘‘Alnico magnets are preferred in speakers because they allow for precision tuning of the magnetic field in the air gap, which creates optimum acoustic performance. The air gap is the air between the poles of a magnet. In the case of speakers, one pole of the magnet surrounds the other pole. The magnetic field in the air gap is very strong and requires precise control, which is possible with alnico magnets.
Electric Guitar Pickups
‘‘One of the most popular uses of alnico magnets is as an electric guitar pickup. The purpose of a pickup is to convert the vibrations of the guitar strings into electrical signals, which are sent on to the amplifier to boost the guitar strings volume. The magnetic properties of alnico 2, 3, 4, and 5 magnets makes them ideal for this application. The pickup makes it possible for an electric guitar to be heard over loud noises.
Grate Magnets
‘‘Grate magnets are a protective device installed in hoppers, floor openings, vertical chutes, and ducts. They are designed to catch and trap fine iron contamination. Weakly magnetic or very fine iron contaminants become trapped in the grate and are later wiped off.
Creating the Alnico Composition
The first step in the manufacturing process is creating the alnico composition. Alnico magnets are made from a combination of aluminum, nickel, cobalt, and iron. These metals are melted together in a furnace and then cooled to create the alnico alloy.
Forming the Alnico Bar Magnet
Once the alnico alloy has been created, it's time to form the alnico bar magnet. The alloy is poured into a mold and then cooled. The resulting bar magnet is then ground down to the desired shape and size.
Heat Treatment
After the magnet has been formed, it's time for heat treatment. This involves heating the magnet to a high temperature and then cooling it rapidly. This process helps to align the magnetic domains within the magnet and increase its overall strength.
Machining
Once the magnet has been heat treated, it's time for machining. This involves grinding down the magnet to the exact size and shape required for its intended use. This step is crucial to ensure that the magnet will fit perfectly into whatever device or application it's being used for.
Magnetizing
The final step in the manufacturing process is magnetizing the alnico magnet. This involves exposing the magnet to a strong magnetic field, which aligns the magnetic domains within the magnet and gives it its magnetic properties.
Alnico Magnet Material
Alnico magnet material is an alloy made up of aluminum, nickel, cobalt and copper, with a rough cast surface which can be ground to close dimensions and to a bright metallic finish. Alnico is electrically conducted, can be E.D.M.'d to form holes and shapes, and can be plated. Alnico is available in a wide variety of shapes and sizes and is typically oriented magnetically through its length. Ideal for high heat applications, alnico can withstand operating temperatures up to 800°F.
Raw magnet material is available in many different types, shapes, sizes and strengths. When selecting magnetic material to perform a given task, certain specifications need to be considered: dimensions, direction of the materials, magnetic orientation, tolerances, finish, strength, and the type of raw magnetic material desired, such as Rare Earth magnets, Ceramic magnets or even Flexible magnetic rubber. Mag-Mate raw magnet material meets Magnetic Materials Producers Association (MMPA) standards for physical quality and magnetic properties.
Designing with Alnico Magnets
When designing with Alnico it is important to consider the shape of the magnet (and hence the Permeance coefficient, Pc), any external demagnetizing forces and the intended use of the magnet. Because Alnico has a lower Hc than the other magnets, it is prone to being easily demagnetized if designed incorrectly. But it can, and is, used in motors and it can offer higher field strengths than the rare earth magnets (by virtue of utilizing the high Br available).
It is a hard yet brittle magnet which is very difficult to machine or drill and is not recommended for structural use.
Also, there are some additional design improvements that can minimize losses from Alnico magnets, such as tapering (making the magnetic poles narrower) and use of steel pole tips (to concentrate the magnetic field to boost performance further and to limit field leakage). In designs where the assembly is a C-shape such that there is a small gap where field is required and the magnetic circuit structure is magnet/steelwork, you will get better performance from Alnico if it is placed either side of the air gap (if Alnico is put in the “back-iron” section further away from the air gap, the air gap field will be much weaker).
Unless the magnet has a very good Pc (Permeance coefficient) it is best to avoid pushing Alnico magnets into each other in repulsion. Because Alnico has low Hc (coercive force) and Hci (Intrinsic Coercive force) values, Alnico can demagnetise itself. This is why many Alnico magnet have “keeper plates” of mild steel – they short-circuit the magnetic circuit to increase the Pc making it harder o demagnetise the magnet whilst in storage.
With correct designing, Alnico can be a very powerful magnet with a superb temperature characteristic that no other magnet can match. It can also be used for applications where fine tuning is advantageous.
Our Factory
Xiamen Qianci Magnet Technology Co., Ltd. was founded in 2000, has a history of more than 20 years, ourcompany is located in Xiamen, Fujian province, is a specialized production and sales of magnet materials, magnet components suppliers. Since the completion of the factory in 2000, our company has continuously innovated products, from the initial iron and boron magnets to now have eight series of products, the company has realized the evolution of products from single to mixed forms, and constantly strengthen its own advantages. More than 100 million new magnet magnets have been transported to the world. For motor, generator and speaker, etc. Our company has always adhered to the "quality first, customer first, quality service, abide by the contract" purpose, with high quality products, good reputation, quality service, products sold in the world Europe, whole heartedly with domestic and foreign merchants win-win cooperation, common development, create brilliant!
Certifications
We always feel that all success of our company is directly related to the quality of the products we offer. They meet the highest quality requirements as stipulated in ISO9001, ISO14000:14001 SGS guidelines and our stringent quality control system.
●ISO/TS16949, VDA6.3, ISO9001, ISO14001 certification company, RoHS, Reach, SGS compliance with products.
●More than 100 million new magnet magnets have been transported to the world. For motor, generator and speaker, etc.
●Senior experts can meet your most complicated requirements.
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