In life, the orientation of the magnet's poles may not matter. However, in other cases, the direction of the magnet is an important part of the intended application. Understanding the general and dedicated magnetization orientation options available can help ensure a successful application.
1. Magnet type based on polarity:
Generally, the magnetization direction starts with two general types of magnetsisotropic and anisotropic.Most magnets are anisotropic, which means they have a preferred direction of magnetization. During magnetization, a magnetic field is applied in the direction of magnetization to orient the material and increase the performance potential of the magnet. Therefore, anisotropic magnets can also be referred to as directional materials.
On the other hand, isotropic magnets have the same magnetic properties in all directions. Therefore, these magnets can be magnetized in any direction. Isotropic magnets, also known as non-directional magnets, are pressed or cast without a specific polarity and magnetized later in the manufacturing process. While this process worked for a wider range of magnetization options, the resulting magnets never reached their full potential. Once magnetized, the directionality of the magnet cannot be changed.
2. Conventional magnetization direction
In most cases, AlNiCo, NdFeB, Samarium Cobalt, and ferrite are magnetized in the normal mode. You can refer to the following general shapes:
Axial magnetization:
Axial magnetization means that the material is magnetized through the length of the magnet. In disk and block magnets, for example, this provides the largest fixed surface area.
radial magnetization:
The radially magnetized material is magnetized by the width of the magnet. For example, bar magnets magnetized by width (or diameter) are often used for sensors.
ball:
Although a professional product mainly used for sensors, the spheres are magnetized in a conventional manner. The sphere is magnetized axially, but simply rotating the magnet puts the poles in the desired position.
Special magnetization direction:
Sometimes engineers, designers, and manufacturers require magnets with shapes and polarities beyond traditional magnetized materials. In these cases, some specialized magnetization directionality include.
Multilevel magnetization:
We offer ceramic blocks and discs with north and south poles on both sides of the magnet. Using directional materials (anisotropic), a multi-pole magnetizing flux passes through the magnet, making both sides of the magnet stronger. Alternatively, for isotropic magnets, the multi-pole magnetizing flux bends inside the magnet, making it stronger on only one side. The flexible magnet sheet is magnetized to have multiple poles on the surface to improve shear strength. Additionally, bar magnets can have multiple poles on the surface to increase holding strength.
Radial magnetization:
Radial oriented magnetization is used in a variety of applications from motors to actuators to sensors. A true radial pattern is magnetized along the inner and outer diameter of the magnet.
Another pattern includes multiple poles around the outer diameter of the ring. This is commonly used for Hall effect sensors, servo motors, couplings and generators.
arc:
Highly specialized radial arcs are widely used throughout the industry. Since it is very difficult and expensive to create a true radial arc (poles radiate outward in a true arc from the center of the arc), approximate radial arcs are most commonly used. In this case, the magnetization is aligned along a straight axis through the arc. Likewise, when a circular arc is required, the approximate circular arc is substituted. This employs parallel magnetization along the width of the arc. In both cases, the approximated arcs lose minimal strength along the outer edge, however, often resulting in significant manufacturing cost savings.
Knowing the directionality of a magnet is the key to choosing the right magnet for your application.