There are many kinds of magnet products, which are generally divided into permanent magnet and soft magnet. What we call magnet generally refers to permanent magnet
Permanent magnet magnets fall into two categories:
The first category is: metal alloy magnets including Ndfeb magnets Nd2Fe14B), SmCo magnets, ALNiCO magnets
The second category is Ferrite permanent magnet materials (Ferrite)
1. Neodymium ferroboron magnet: It is the most commercially available magnet and is known as the magnetic king. It has a very high magnetic property, its maximum magnetic energy product (BHmax) is 10 times higher than Ferrite. Its own mechanical processing performance is also quite good, operating temperature up to 200℃.
And its texture is hard, performance is stable, have very good cost performance, therefore its application is extremely extensive.
However, because of its strong chemical activity, it must be coated on the surface.
2. Ferrite magnet: Its main raw materials include BaFe12O19 and SrFe12O19) Made by ceramic process, it is a hard and brittle material. Ferrite magnet has become the most widely used permanent magnet because of its good temperature resistance, low price and moderate performance.
3. Aluminum-nickel-cobalt magnet: An alloy of aluminum, nickel, cobalt, iron, and other trace metal elements.
The casting process can be processed into different sizes and shapes with good machinability.
Casting al - Ni - Co permanent magnet has the lowest reversible temperature coefficient, the working temperature can be up to 600℃.
Al-ni-co permanent magnet products are widely used in various instruments and other applications.
4. SmCo can be divided into SmCo5 and Sm2Co17 according to different components.
Its development is constrained by the high price of its materials.
As a rare earth permanent magnet, SmCo has high magnetic energy product (14-28MGOe), reliable coerce and good temperature characteristics.
Compared with Ndfeb magnets, samarium cobalt magnets are better suited to work in high temperatures.
Are magnets bad for you?
1. Magnetic field damage: we know that the magnetic field will promote blood circulation to the human body, there is no data to show that the magnetic field has direct damage to the human body, so there is no need to worry too much about the magnetic field.
2.The magnetic field of have a harm to human body, size depends on the strength of the magnetic field, in general, the magnet under 3000 gauss (magnetic field), no harm to human body, more than 3000 magnet magnetic field strength, there is a harm to human body. The magnet while harmful to human body but someone afraid of negligible magnetic field affect the body, but according to the test, magnetic field effects on people is only one 5 of the television.
3. Direct harm of the magnet to human body: Although the magnetic field of the magnet does no harm to human body, direct contact with the magnet itself may cause direct harm to people in the following ways.
1) Direct suction of magnets may cause injury, especially ndFeb strong magnets and large magnets do more damage to human body.
2) Magnets enter the body through the mouth more serious injury, may harm life, because the magnet itself is magnetic, the mutual suction in the body will cause intestinal perforation in the body, and then cause massive bleeding, the situation will endanger life, please carefully magnet directly to children play.