The use of magnets has pervaded many sectors of human lives. Magnets are extensively used for a wide range of applications such as commercial, domestic and industrial purposes. Again, magnets are mostly found in three kinds namely permanent magnets, temporary magnets and electromagnets. Moreover, in all these type of magnets, the permanent magnets are the ones the average person is most familiar with. A very good example of permanent magnets used in daily life is the refrigerator magnets.
Definition Of Permanent Magnets
Permanent magnets are highly appreciated because once magnetized, they retain their level of magnetism. A permanent magnet
comprises of an object made from a magnetized material which further creates its own persistent magnetic field. Good permanent magnets are available in an array of shapes and produce a high magnetic field with a low mass.Further, when looking for good permanent magnet, one has to look into its stability against the influences that can demagnetize it.
Properties Of Permanent Magnets
Different permanent magnets can display diverse characteristics and properties.Parameters that distinguishes one permanent magnet from the other are-
Types Of Permanent Magnets
- How easily they can be demagnetized
- Their strength
- Change in their strength depending on the temperature
Some of the names of different types of permanent magnets used for diverse applications are Neodymium, Samarium-cobalt, Alnico, Ceramic (also known as ferrite) and so on.
Neodymium and samarium-cobalt magnets are classified as rare earth magnets.This kind of rare earth magnet produces the largest magnetic flux with the smallest mass. Neodymium and samarium-cobalt magnets are known for being the strongest of all the permanent magnets and are difficult to demagnetize. Again, the Alnico magnet comprises of aluminum, nickel and cobalt. This type of permanent magnet is not easily affected by temperature but on the other hand, it is easily demagnetized.
Lastly, the ceramic or ferrite magnets are perhaps the most popular type of magnet, mostly because of their flexibility. This type of Ceramic magnets is flexible and often thin, meaning that they can be bent and moved in a number of different ways. These features make the Ceramic magnets excellent choices for advertising and marketing applications. Also, the Ceramic magnets exhibit sturdy construction and are not easily demagnetized. However the strength of Ceramic magnets varies greatly according to the temperature.
Permanent Magnets Usage
Again, the permanent magnets are also used in diverse applications, including:
Mechanical applications depending on the attractive and repelling force of the magnet includes Magnetic separators, magnetic holding devices, Magnetic torque drives and Magnetic bearing devices Again, Mechanical energy applications rely on using the magnetic field of a magnet to convert electrical energy to mechanical energy in cases such as Meters, Motors, Speakers and Relays
- Electrical energy applications
Electrical energy applications entail the conversion of magnetic field of a magnet to mechanical energy and then into electric energy. Such applications include generators and alternators and Eddy current brakes
Direct Applications are meant to shape and control electron and ion beams by using a magnet's magnetic field. Such applications include Ion Pumps, Cyclotrons and Cathode-ray tubes
Thus, Permanent magnets are the most widely used magnet that is used in numerous applications. At the same time, the correct choice of a permanent magnet is of utmost significance and should be done on the basis of strength, performance in temperature and whether it is easily demagnetized.