Understand the difference between bonded NdFeB and sintered NdFeB?

Neodymium iron boron magnetic materials, as the result of the development of rare earth permanent magnetic materials, are called "magneto king" because of their excellent magnetic properties. Neodymium iron boron magnetic materials are alloys of praseodymium neodymium metal, ferroboron, etc. Also known as magnetic steel. NdFeB has extremely high magnetic energy product and coercivity. At the same time, the advantages of high energy density make NdFeB permanent magnet materials widely used in modern industry and electronic technology, which makes it possible to miniaturize, lightweight and thin instruments, electroacoustic motors, magnetic separation magnetization and other equipment.

NdFeB magnets can be divided into bonded NdFeB magnets and sintered NdFeB magnets. The difference between the two is mainly in the process. Bonded Nd-Fe-B is made by adding NdFeB magnetic powder into adhesive. Bonding is actually injection molding, while sintering is vacuum pumping and high-temperature heating molding! Sintered Nd-Fe-B permanent magnet material adopts powder metallurgy process. The melted alloy is made into powder and pressed into pressed embryo in magnetic field. The pressed embryo is sintered in inert gas or vacuum to achieve densification. In order to improve the coercivity of magnet, aging heat treatment is usually required.

Bonded NdFeB magnet is a magnet made by "press molding" or "injection molding" by mixing rapidly quenched NdFeB magnetic powder and binder. It has the advantages of high remanence, high coercivity, high magnetic energy product, easy processing of various sizes and minimum specifications. It is mainly used in the fields of office automation equipment, electrical installation machinery, audio-visual equipment, instruments and meters, small motors and metering machinery.

Sintered NdFeB permanent magnet materials have excellent magnetic properties and are widely used. The more common are permanent magnet motors, speakers, magnetic separators, computer disk drive tables, etc.

NdFeB magnet is the permanent magnet with the strongest magnetic force so far. Material grades are n35-n52; Various shapes can be processed according to specific requirements: round, square, drilling, magnetic tile, magnetic rod, convex, trapezoid, etc; Despite these advantages, the surface is easy to rust, so some protective surface treatments are usually required: nickel plating, zinc plating, gold plating, epoxy resin plating, etc. The applicable ambient temperature of ordinary NdFeB magnets is below 80 degrees, but there are several that can withstand 200 degrees.