Magnetization (orientation) direction and type2018-07-20
Magnetization (orientation) direction and type
A magnet that has no orientation direction (also called an isotropic magnet) is much weaker than an orientation magnet (also called an anisotropic magnet). What is the standard “North-Arctic” industrial definition? "Arctic" is defined as the north pole of the earth pointing to the north pole of the earth after the magnet rotates freely. Similarly, the south pole of the magnet also points to the south pole of the earth. How to identify the north pole of the magnet without marking? Obviously it is impossible to distinguish only by the eyes. You can use the compass to stick to the magnet, and the pointer to the north pole of the Earth points to the south pole of the magnet. How to handle and store magnets safely? Always be very careful, as the magnets will stick together and may pinch your fingers. When the magnets are attracted to each other, the magnet itself may be damaged by the collision (the corners are knocked off or the cracks are knocked out). Keep magnets away from items that are easily magnetized, such as floppy disks, credit cards, computer monitors, watches, mobile phones, medical devices, etc. Keep the magnet away from the pacemaker. For larger magnets, plastic or cardboard spacers should be placed between each piece to ensure that the magnets can be easily separated. The magnet should be stored in a dry, constant temperature environment as much as possible. How to achieve magnetic separation? Only materials that can be attracted to the magnet can function to block the magnetic field, and the thicker the material, the better the magnetic separation effect. What is the strongest magnet? At present, the highest performance magnet is a rare earth magnet, and in the rare earth magnet, neodymium iron boron is the most powerful magnet. However, in the environment above 200 degrees Celsius, samarium cobalt is the most powerful magnet.
Type of magnet
Magnets, which should be called magnetic steel, English Magnet, magnetic steel are now mainly divided into two categories, one is soft magnetic, one is hard magnetic; soft magnetic includes silicon steel sheet and soft magnetic core; hard magnetic includes aluminum nickel cobalt, samarium cobalt Ferrite and NdFeB, among which the most expensive is samarium cobalt magnet, the cheapest is ferrite magnet, the highest performance is NdFeB magnet, but the performance is the most stable, the temperature coefficient is the best The aluminum-nickel-cobalt magnetic steel allows users to choose different hard magnetic products according to different needs. How to define the performance of the magnet? There are three main performance parameters to determine the performance of the magnet: Remanent Br: After the permanent magnet is magnetized to the technical saturation, and the external magnetic field is removed, the retained Br is called the residual magnetic induction. Coercive force Hc: The B of the permanent magnet magnetized to the technical saturation is reduced to zero. The required reverse magnetic field strength is called the magnetic coercive force, which is simply referred to as the coercive force energy product BH: represents the magnet in the air gap. The magnetic energy density established by the space (the two magnetic pole spaces of the magnet), that is, the magnetostatic energy per unit volume of the air gap. Since this energy is equal to the product of the Bm and Hm of the magnet, it is called the magnetic energy product. Magnetic field: The space that magnetically acts on the magnetic pole is the magnetic field. Surface magnetic field: The magnetic induction intensity at a specified position on the surface of the permanent magnet How to choose a magnet? Before deciding which magnet to choose, what role does the magnet need to play? Main role: moving objects, fixing objects or lifting objects. The shape of the required magnet: a disk shape, a circular shape, a square shape, a tile shape or a special shape. The size of the required magnet: length, width, height, diameter and tolerance, etc. The suction of the required magnet, the expected price and quantity, and so on. The compass is invented according to the nature of the magnet.