NdFeB, namely Neodymium(Nd) -Iron(Fe)-Boron(B), the third generation of rare-earth permanent magnets and the strongest permanent magnets to date, has not only the excellent qualities of high remanent magnetization, high coercive force and high magnetic energy product but also the advantages of being easy to process and a relatively high performance/cost ratio. Since made from Neodymium, one of the most plentiful rare-earth elements, and inexpensive iron, NdFeB magnets offer the best value in cost and performance. For NdFeB, its surface is usually treated with some special methods. The surface treatment method include Zinc, Nickel, Tin, Sliver, Gold plating, Phosphor and Spray Epoxy Resin etc. NdFeB magnets are available in both sintered and bonded forms. Sintered NdFeB offers the highest magnetic properties (33 MGOe to 51 MGOe) while Bonded NdFeB offers lower energy properties. Although bonded magnets do not possess magnetic properties as advanced as those of sintered magnets, they can be made in shapes and sizes that are difficult to achieve with sintering.
NdFeB is now widely used in apparatus and instruments where a strong magnetic field is needed such as devices for avionics, spacecraft, electronic instruments, electro-acoustic devices, electrical machinery, meters and medical instruments. This magnet is thus especially suitable for developing those new products demanding high quality, small volume and light weigh. NdFeB magnet can be used as an ideal magnet in mini-motor, permanent magnet instrument, electronic industry, auto industry, petro-chemical industry, nuclear magnetic resonance, sound device magnetic suspension system, magnetic transmission machine and iatrical apparatus and etc.
Industrial application of magnetic equipment depends largely on the development of new permanent magnets. Following outlines subjects that the permanent magnets users desires to see it happen:
- Cost effectively manufactures magnetic ndfeb blocks with large variety of geometry.
- Study the change of magnetic properties under industrial environment, particular under mechanical stress and corrosive environment. These data are not yet available for industrial evaluation.
- Study magnet after effect on permanent magnet. The user are lack of the basic data on how long the sintered NdFeB magnet will keep the magnetic strength under various deŽmagnetization fields. We run very often into the situation to be asked to warrant magnetic field strength within certain length of time.
- Magnet surface coating not only to protect corrosion but also strong enough to become wear resistance.
- Increase Br and hence (BH)max under condition of Hci>14 kOe at room temperature.
- NdFeB Hydrogen embrittlement process is now widely used in sintered NdFeB manufacturing process, the powderization of ndfeb magnet becomes an issue particularly in industrial wet application. The hydrogen effect in the finished ndfeb magnet on magnet's corrosion properties is yet to study.
Conclusion:There are enormous industrial applications of rare earth magnets are yet to find. We strongly believe that more quality magnets used in the industry leads to a higher level of the living standard. The endless desire of mankind for a higher and better living standard is the motivation for continuous development of the industrial magnet equipment. With the rapid industrialization and modernization, there are more opportunities for magnet applications in Chinese industry. Continuous improvement from both materials and design aspects will make innovation of magnetic equipment a fascinating working area. Collaboration between ndfeb magnet users and ndfeb magnet manufacturers requires discipline, encouragement, patience and wisdom, and after all, it is rewarding, to both sides.