What are the properties of Alnico magnets?

What Are the Properties of Alnico Magnets?

Alnico magnets, composed of aluminum (Al), nickel (Ni), and cobalt (Co), are one of the most popular permanent magnet materials like with Axial Flux Permanent Magnet Generator.

They were developed in the 1940s and have several important properties that make them a preferred choice for many applications. These include:

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Resistant to Corrosion

Alnico magnets are known for their excellent corrosion resistance. This is a trait that is important to product teams, particularly in the power, aerospace and automotive industries.

Corrosion is a process where the material becomes oxidized due to rust or other chemicals that eat away at it, which causes it to lose its magnetic properties. Iron is the most corrosive of all metals, but the alloy that Alnico is made from has very little iron in it, which is why it is so resistant to corrosion.

Alnico is available in cast and sinterable versions, with the former containing powdered aluminum, nickel and cobalt and the latter being produced by heating and cooling to a specific temperature. This process allows the magnets to be cast into complex shapes, for example horseshoe shaped, that cannot be done with other types of magnets.

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High Temperature Resistance

Alnico magnets are manufactured from a combination of aluminum, nickel and cobalt. They are a common choice for applications that require high temperatures like Bonded NdFeB magnets.

These magnets are the workhorse of the permanent magnet industry. They have a unique crystalline bonding between aluminum, nickel and cobalt, which provides an exceptional degree of heat resistance and strength.

Alnico magnets can be manufactured in a variety of ways, including casting and sintering. Cast magnets are poured into a mold and then cooled and ground before being magnetized.

High Remanence Strength

Alnico magnets are known for their high remanence strength. Compared to ferrite and SmCo, they have higher remanence values in closed loop magnetic configurations (as shown in Table 5).

The remanence of Alnico magnets varies depending on the geometric shape of the magnet. Shorter and thicker specimens have higher remanence values.

This is because the field strength at the poles of a permanent magnet depends very much on its shape. A magnet with a shorter and thicker shape will have more resistance to demagnetization from less than ideal geometries.

Alnico magnets are typically produced by casting an alloy containing Fe, Co, Ni and Al. The alloy is then annealed in a magnetic field to produce needle shaped particles that have very high shape anisotropy.

High Coercivity

Alnico magnets are strong permanent magnets that have exceptionally high coercivity (resistance to loss of magnetic property). Only rare earth magnets like neodymium and samarium-cobalt have a higher coercivity.

These types of magnets are used in many different applications, such as alarm systems, electric motors, guitar pickups, and sensors. They are also used in geological detection devices and defense and aerospace technology.

Although alnico has a high coercivity, it is a complex material that requires careful processing to ensure the right properties are achieved. In addition, it is prone to chemistry change that affects the nanostructure of the Fe-Co rods during cooling.

Long Life

Alnico magnets have a long life, allowing them to be used in many different applications with Sintered NdFeB magnets. They are commonly found in sensors, guitar pickups and loudspeakers among other products.

They are composed of mainly Aluminum, Nickel and Cobalt alloys and are manufactured through a variety of processes including casting and sintering. Cast Alnico magnets are generally stronger than sintered ones but offer a slightly lower magnetic property.

Alnico magnets are characterized by their high temperature stability and high residual induction properties. This makes them ideal for sensor, instrumentation and rotating machinery applications.