How to Understand the Grade of Sintered NdFeB Magnet?

How to Understand the Grade of Sintered NdFeB Magnet? Generally, the grades of sintered neodymium iron boron (NdFeB) magnets are strings containing three parts, i.e. “N” + “number” + “letter”. The left part “N” is the initial letter of neodymium, meaning it is sintered NdFeB magnet. So it is constant for all the grades. The middle part “number” represents value of maximum energy product (BH)max (in CGS unit). The value varies from 28 to 52. The right part “letter” reflects… Read More

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What are Rare Earth Permanent Magnets (REPMs)?

What are Rare Earth Permanent Magnets (REPMs)? Rare earth permanent magnets (REPMs) are permanent magnets which are based on some rare earth elements (Sm, Nd, Pr, Dy, Ce, etc.) to form critical magnetic structures. In regard to crystal structures, REPMs include a. 1:5 type SmCo magnets (hexagonal CaCu5 type structure) also called 1st generation REPMs, b. 2:17 type SmCo magnets (rhombohedral Th2Zn17 type structure) also called 2nd generation REPMs and c. Nd2Fe14B magnets (tetragonal crystal structure) also called 3rd generation… Read More

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What is a Permanent Magnet?

What is a Permanent Magnet? A permanent magnet is a material that is able to provide magnetic flux when magnetized with an applied magnetic field. The ability is characterized by two key parameters: remanence and coercivity. Generally, a permanent magnet’s intrinsic coercivity (Hcj) is higher than 300kOe (in CGS unit) or 24kA/m (in SI unit). With higher coervivity, a permanent magnet has higher ability to resist demagnetization, including field demagnetization from the electric or magnetic circuit and thermal demagnetization from… Read More

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