Sintered NdFeB Magnets

Neodymium magnet, also known as NdFeB magnet, is a tetragonal crystal formed by neodymium, iron and boron (Nd2Fe14B). In 1982, Sagawa Masato of Sumitomo Special Metals discovered neodymium magnet. The magnetic energy product (BHmax) of this magnet is greater than that of samarium cobalt magnet, and it was the material with the largest magnetic energy product in the world at that time. Later, Sumitomo Special Metals successfully developed the powder metallurgy process, and General Motors successfully developed the melt-spinning process, which can produce neodymium iron boron magnets. This magnet is the permanent magnet with the second highest magnetic property after the absolute zero holmium magnet, and it is also the most commonly used rare earth magnet. Neodymium iron boron magnets are widely used in electronic products, such as hard disks, mobile phones, headphones, and battery-powered tools.

In order to avoid corrosion damage, it is necessary to protect the surface of the permanent magnetic material during use, such as electroplating with gold, nickel, zinc, and tin, and spraying epoxy resin on the surface.

NdFeB is divided into sintered NdFeB and bonded NdFeB. Bonded NdFeB is magnetic in all directions and corrosion-resistant. Sintered NdFeB is easy to corrode, so the surface needs to be plated, generally with zinc, nickel, environmentally friendly zinc, environmentally friendly nickel, nickel-copper-nickel, environmentally friendly nickel-copper-nickel, etc. Sintered NdFeB is generally divided into axial magnetization and radial magnetization, which is determined according to the required working surface.