Permanent Magnet Applications Guide

How are magnets used? To answer this question, let’s review the main features of each of our product groups, identify the specific applications of each product, and then detail the operation of the various magnetic devices.

Permanent magnet application categories and examples

Permanent magnet applications can be divided into the following four categories:

Application 1
Use the attraction and/or repulsion of a magnet (i.e. the attraction between a magnet and a soft magnetic material (such as a piece of iron or steel), or the attraction or repulsion between two magnets) to do mechanical work. The following applications fall into this category:

Magnetic separators, magnetic holding devices (e.g. magnetic latches).
Magnetic torque driver
Magnetic bearing device
Application 2
An application that uses the magnetic field of a magnet to convert mechanical energy into electrical energy. These applications include:

magneto
Generators and alternators
Eddy current brake (widely used for meter damping). (This application can be listed under the conversion of electrical to mechanical energy; However, as vortices are generated using mechanical energy, they will be discussed with this group.)
Application 3
The application of converting electrical energy into mechanical energy using magnetic fields of magnets. These applications include:

Electric machine
appearance
loudspeaker
relay
Application 4
Applications that use magnetic fields of magnets to guide, shape, and control electron or ion beams. These applications include:

Magnetic focusing cathode ray tube
TWT
Magnetron, BWO, klystron
Ion pump
cyclotron

Products applications

The purpose of a permanent magnet is to create a magnetic flux in the working gap of the device. Obviously, all permanent magnet materials produce magnetic flux, but depending on the working application, some material types, grades, and shapes will be more efficient than others. The following is a breakdown of product line applications by most suitable material characteristics:

Casting aluminum nickel cobalt
The main properties of cast aluminum nickel cobalt are:

High mechanical strength
Cast into various shapes
Very stable temperature
The magnetic direction can be changed
Compared with ceramic materials, Br and Bhmax have higher properties.
Sintered aluminium nickel cobalt
The main properties of sintered aluminium nickel cobalt are:

Highest mechanical strength aluminum nickel cobalt
Pressing with small tolerances/usually minimal grinding
Note: Both cast and sintered AlNICo have very low Hc compared to ceramic or rare earth materials.

Aluminum-nickel-cobalt applications
Common applications for casting and sintering aluminium nickel cobalt include:

Electron tube, radar, travelling wave tube
Separators, holding magnets, coin receivers, clutches and bearings
Magneto, motor, generator, meter, instrument, controller, relay, electric meter (bearing and shock absorber)
Communication, receiver, telephone, microphone, ringer, instrument (guitar pickup)
Automotive sensors, speakers, cow magnets, dispensers
Ferrite magnet
The main properties of ceramic magnets and Arnold products include:

Compared with aluminum nickel cobalt, economical, Hc and Hci higher
Ferrite magnet applications

Dc permanent magnet motors used in the automotive industry for blowers, window lifters, windshield wipers, etc. (Note: Many motors come from external sources and are not directly related to the car company itself). Separators are used to remove ferrous materials from liquid powders and bulk commodities
Magnetic resonance Imaging (MRI)
Magneto for lawn mowers, garden tractors and outboard motors
Brushless DC motor with speed and direction controller.
RECOMA® Samarium Cobalt
Samarium-cobalt magnets have the following characteristics:

High Hc and Hci
High Bhmax
Very good temperature stability
Small size, large power
Samarium-cobalt application

TWT
Computer hard disk drive
Temperature stability is critical for DC motors, such as satellite systems and small motors for defense
Automotive application
Linear actuator
Neodymium iron boron
The main reasons for using neodymium are:

Large size, high energy
More economical than samarium cobalt
Suitable for room temperature applications
Very high Hc and Hci output
Ndfeb applications

Computer hard disk drive
Linear actuator
Hammerbank printer
loudspeaker
Microphone assembly
Magnetic separator
Dc motors and car starters
Servo motor