Rare earth magnets are new functional materials developed since the 1960s and the application of rare earth magnets is very broad today. They have been widely used in microwave communication technology, audio and video technology, electrical engineering, instrument technology, computer technology, automation technology, automobile industry, petroleum industry, magnetic separation technology, biological engineering, and magnetic therapy and fitness equipment. In this article, let’s take a deeper look at the application of rare earth permanent magnets.
In radar technology, satellite communication, remote control telemetry technology, electronic tracking, electronic countermeasure technology, magnetron electron tubes, magnetron traveling wave tubes, cathode ray tubes, microwave ferrite isolators, circulators, etc. are needed. All these devices use permanent magnets to generate a constant magnetic field to control the movement of the electron beam to achieve high-frequency or ultra-high frequency oscillation, microwave signal amplification, reception, and display functions.
About 1/3 of the output of rare earth permanent magnets is used to manufacture various permanent magnet motors. There are many types, uses, and varieties of permanent magnet motors, and the motors have different capacities. They are widely used in modern science and technology and various sectors of the national economy. The advantages of permanent magnet motors are that they do not require excitation windings or exciters, saving copper, saving electricity, light in weight, small in size, and high in specific power. The emergence of high-performance rare earth permanent magnets, especially NdFeB permanent magnets, has promoted the development of permanent magnet motors.
According to statistics, 10-15% of permanent magnets are used to manufacture various magnetoelectric instruments and various timing devices. The iron core of the stepping motor of the electronic watch is generally made of the bonded permanent magnet.
About 15% of rare earth permanent magnets are used to make electroacoustic devices. The electroacoustic device is a general term for speakers, microphones, pickups, hearing aids, stereo headsets, telephone receivers, and electroacoustic sensors. The principle of electroacoustic devices is basically the same. When a current flows through the voice coil in the air gap, under the action of the air gap magnetic field, it will vibrate and cause the paper plate to vibrate and produce sound.
Magnetic machinery is a new application field that has gradually developed after the emergence of rare earth permanent magnets. Magnetic machinery includes magnetic actuators or magnetic “gears”, magnetic brakes, magnetic clamps, magnetic salvage devices, magnetic bearings, magnetic pumps, magnetic valves, magnetically sealed doors, and magnetic locks.
There are many types of magnetic machinery, but the principle is the same, that is, using the repulsive force of the same polarity or the attractive force of different polarities. For example, a magnetic actuator uses the principle of the mutual attraction of different magnetic poles to form a non-contact transmission inside and outside a sealed or vacuum container. It is characterized by no contact between the magnetic poles, no friction, and can be used in vacuum systems or the chemical industry. For another example, a magnetic bearing uses the principle of same-polarity repulsion, and two magnets of the same polarity are opposed to each other to form a magnetic repulsion field and work in this field.
There are two types of magnetic bearings, horizontal and vertical. They are mainly used in artificial satellites, spacecraft, high-speed aircraft gyroscopes, ultra-high-speed centrifuges, textile machine turbines, electricity meters, special-purpose motors, precision instruments, and watt-hour meters. Artificial satellites or spacecraft generally work under vacuum conditions. In a vacuum, mechanical bearings face serious lubrication and wear problems, which determine the life of artificial satellites and high-speed aircraft. Magnetic bearings have no friction and do not need lubrication, so they can be long-term use.
The train manufactured by the principle of mutual repulsion of the same magnetic poles is called a maglev train. The wheels of this train are not in contact with the track. It relies on magnetic repulsive force to levitate the body. This kind of train has a high speed during operation, and the speed can reach 500km/h, and the general train speed is less than 300km/h. In addition, there is no friction and no noise. It is an ideal transportation tool in the future.
The technique of separating ferromagnetic substances from non-ferromagnetic substances or magnetic atoms (ions) or magnetic molecules from non-magnetic atoms (ions) or non-magnetic molecules using magnetic methods is called magnetic separation technology. Magnetic separation technology has been applied in mineral processing, raw material processing, water treatment, garbage treatment, chemical industry, food industry, and its application scope will be expanded day by day.
The magnetic field is used to magnetize the substance to change the bond state of the magnetized substance, or the configuration of atoms and electrons, promote the chemical reaction of the substance, promote fuel combustion or change the crystalline form or freezing point of the substance. This technology is called magnetization technology.
The magnetization technology has been increasingly recognized and valued by people. For example, the hard water that has been magnetized no longer scales, and watering with magnetized water can promote the growth of organisms. There are reports that drinking magnetized water can treat diseases.
Rare earth permanent magnets have been used for magnetic therapy and fitness equipment, such as static magnetic medical magnetic sheets or balls, magnetic therapy machines, magnetic therapy water cups, magnetic therapy shoes, hats, necklaces, etc. In recent years, a new type of human disease diagnosis equipment called MRI has been developed.
Thank you for reading our article and we hope it can help you to have a better understanding of the application of rare earth magnets. If you want to know more about rare earth magnets, we would like to advise you to visit Stanford Magnets for more information.
As a leading magnet supplier across the world, Stanford Magnets has been involved in R&D, manufacturing, and sales of rare-earth permanent magnets since the 1990s. It provides customers with high-quality permanent magnets like neodymium magnets, SmCo magnets, AlNiCo magnets, and ferrite magnets (ceramic magnets) at a very competitive price.