Sintered NdFeB magnet is a permanent magnet material. All Sintered NdFeB magnets have excellent performance, abundant raw material and reasonable price, so that they are to be a rapid development and a wide range of applications. Sintered NdFeB magnets’ main application is in micro motors, permanent magnet instrument, electronic industry, automobile industry, petrochemicals, nuclear magnetic resonance, sound device magnetic suspension system, magnetic transmission machine and magnetic therapy equipment, etc.
Easy to rust, oxidation, sintered NdFeB magnets’ surface is usually required for plating processing, such as zinc, nickel, silver, gold, and can also Phosphor and Spray Epoxy Resin slow down its rate of oxidation.
Sintered NdFeB magnets are manufactured using powder metallurgy method. Well, what the specific process of sintered NdFeB magnets is likes? Simple in terms, is to prepare the raw materials, smelting, magnetic field orientation, and pressure type, and then sintered. According to the process order, the following will briefly describe the process principle of sintered Nd-Fe-B magnets.
The magnetic properties of sintered NdFeB magnets by Nd2Fe14B matrix phase to decide. Mainly because of the strength of the magnetic polarization Js (Js = μ0Ms, Ms is the saturation magnetization) and anisotropy field HA depends on the chemical composition of Nd2Fe14B phase. Alloy design and the choice of raw materials are crucial.
The purpose of melting the material of the pure metal (Fe, Nd, B-Fe, Dy, A1, Nb, Co, Cu, etc.) is melted, and to ensure that all of the metal material melts cleared. The high melting point of pure Fe and Nd metal, should try to make them completely melt and clear, to ensure the accuracy of the design elements of the alloy.
The powder magnetic field orientation is one of the manufactures of high-performance sintered NdFeB magnets is another key technology. The sintered NdFeB magnets of the magnetic energy is mainly derived from having a tetragonal Nd2Fe14B matrix phase, which is a uniaxial anisotropic crystal C axis is the easy axis of magnetization, a shaft embarrassed magnetization axis.
The sintering process is heated to the Nd-Fe-B powder compacts powder matrix phase below the melting temperature of approximately (0.70 ~ 0.85) T melting insulation treatment for some time. The aim is to increase the density of the compacts, to improve the nature of the contact between the powder particles, improve strength, sintered NdFeB magnets with high magnetic properties micro structural features.
The ingot structure not only for milling, orientation, sintering process, and the powder properties and the final sintered magnetic can have an important effect. No the excellent ingot organization, it is impossible to create a high performance sintered NdFeB magnets. The ingot organization is one of the key technologies of restricting the performance sintered NdFeB magnets.
