Acting as one of the significant materials that promote modern technology and social progress, the sintered NdFeB permanent magnet is widely applied to the following fields: computer hard disk, zeugmatography, electric vehicle, winder power generation, industrial permanent magnet motor, consumer electronics (CD, DVD, mobile phone, stereo, copying machine, scanner, vidicon, camera, refrigerator, TV, air-conditioner, etc.), as well as magnetometric machinery, magnetic suspension technique, magnetic transmission and other industries.
Since 1985, Japan, China, Europe and American countries started to be industrialized at the same time, during the recent 30 years, the global industry related to permanent magnet material is booming, the magnetic property refreshes new record continuously, and the material category and mark are increasing. Along with the market expansion, the number of production manufacturers is escalating. However, it is inevitable for many customers to fall into such confusion, how to judge the product quality?
The most comprehensive judging methods: 1. Magnet’s property; 2. Magnet’s dimension; 3. Magnet’s coating.
First of all, the guarantee of magnetic property comes from the control of raw material production process.
1. According to the requirements of manufacturing high-end or medium-end or low-end sintered NdFeB in enterprise, whether the raw material is selected in line with the raw material components stipulated in national standard.
2. Whether the production technology is advanced decides the property and quality of the magnet directly. Currently the state of the art technologies is SC technology, HD technology and JM technology. The vacuum induction smelting furnace with small capacity (10kg, 25kg and 50kg) have been replaced by such furnace with large capacity (100kg, 200kg, 600kg and 800kg).
The SC (Strip Casting) technology has replaced large ingot casting (refers to the cast steel with the thickness of more than 20-40mm in the cooling direction) gradually, meanwhile HD technology and JM have replaced jaw crusher, disc mill and ball mill (powder milling in wet method), so that the homogeneity of the powder has been ensured, and are beneficial for liquid-phase sintering and grain refinement.