Relative strength
The magnetic field strength generated by the magnet is quantized by BHmax or the maximum energy product, and BHmax or the maximum energy product is measured by MGOe. The higher the BHmax, the greater the force of the magnet. The BHmax of ferrite magnet is 3.5, that of SmCo is 26, and that of NdFeB is the most powerful rare earth magnet, with a BHmax of 40.
Relative resistance of thermal stress
Magnets begin to lose strength when heated to a certain temperature (Tmax), so they should not work outside that temperature. However, when cooled below Tmax, they will regain power. Tmax of ferrite magnet is 300 ℃, that of samarium cobalt magnet is 300 ℃, and that of neodymium iron boron magnet is 150 ℃.
Relative durability
Magnets can resist not only thermal stress, but also other stresses. NdFeB magnets are fragile and difficult to process. They are also susceptible to corrosion. SmCo magnets are less brittle and difficult to process, but have high corrosion resistance. SmCo magnets are also the most expensive type of magnets. Ferrite magnets are cheaper than samarium cobalt and neodymium iron boron magnets, and have good demagnetization and corrosion resistance.
Ferrite and neodymium magnets have different advantages. Ferrite magnets are easily magnetized. They are very corrosion resistant and usually do not require additional anti-corrosion coatings. They can resist demagnetization of external magnetic fields. They are stronger than natural magnets, although many other types of magnets are stronger than them. They are relatively cheap. Neodymium magnets are the most powerful of all permanent magnets. Neodymium magnets can lift more force than any other type of magnets of the same size. Ferrite and neodymium magnets also have different disadvantages. Ferrite magnets are very fragile. They can '; It shall not be used in machinery subject to great pressure or bending. If exposed to high temperatures (more than 480 degrees Fahrenheit), they will be demagnetized. They only have medium strength magnetic fields, and are not suitable for applications requiring strong magnetic fields. Neodymium magnets are relatively more expensive than ferrite magnets. They are easy to rust and additional measures must be taken to prevent corrosion. Neodymium magnets are also very fragile and can break under pressure. If exposed to temperatures in excess of 175 to 480 degrees Fahrenheit, they lose their magnetism
