Rare Earth Permanent Magnets 归档 - Page 2 of 2

Do Magnets ever Lose Their Magnetism or Get Weaker?

Actually permanent magnets are not permanent. A Permanent Magnet is a material which has ability to resist demagnetization, including filed demagnetization and thermal demagnetization. The ability is characterized by a physical parameter called coercivity. In regard to field demagnetization, if a demagnetizing field or reverse field is smaller than a permanent magnet’s coercivity, the permanent magnet will keep the same magnetic flux (the demagnetizing process is linear and reversible when the demagnetizing field is lower than a threshold value) or… Read More

multi pole radially ring magnet straight

Radially Oriented NdFeB Ring Magnets

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Radially oriented neodymium iron boron (NdFeB) ring magnets are state-of-the-art ring magnets with diverse magnetization patterns in radial direction. In general, they provide high performance and cost-effective alternatives to arc/segment magnets. According to different production processes, radially oriented NdFeB ring magnets include sintered NdFeB ring magnets, bonded NdFeB ring magnets and hot-pressed NdFeB ring magnets. single pole radially ring magnet multi-pole radially ring magnet (straight) multi-pole radially ring magnet (skew)

What is the Difference between N35 and N52 Magnets?

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What are N35 and N52 magnets? Seen from their grade strings, both of them are sintered neodymium iron boron (NdFeB) magnets. These two magnets have the same intrinsic coercivity Hcj level higher than 12 kOe (in CGS unit) or 955 kA/m (in SI unit). It is also obviously seen that their maximum energy product (BH)max are around 35 and 52 MGOe, respectively. This huge difference means that the N52 magnets have around 49% more energy than that of the N35… Read More

Corrosion Resistance of Rare Earth Permanent Magnets

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In the Rare Earth Permanent Magnets family, the 1st generation 1:5 type SmCo magnets and 2nd generation 2:17 type SmCo magnets have high corrosion resistance due to the high cobalt content. Just like ferrite/ceramic magnets and AlNiCo magnets, SmCo magnets usually do not need any treatment for applications. The 3rd generation NdFeB magnets, however, are not the same. Although they have superior magnetic properties, they are more vulnerable to corrosion in humid environments, resulting in the deterioration of magnetic properties… Read More

XGS28H grade SmCo magnet demagnetization curve

Sintered SmCo Magnet Grades

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Samarium cobalt (SmCo) magnets include 1:5 type (SmCo5) and 2:17 type (Sm2Co17) magnets. Both types of SmCo magnet grades basically include three parts, i.e. “letter 1” + “number” + “letter 2”. The three parts in sintered SmCo magnet grades present material type, (BH)max value (in CGS unit) and Hcj level, respectively. The part “letter 1” are “XG” and “XGS” for sintered SmCo5 and Sm2Co17 magnets, respectively. Besides, the Hcj levels of sintered SmCo5 magnets include “default” (Hcj ≥ 15 kOe)… Read More

Bonded NdFeB Magnet Grade

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Unlike sintered NdFeB magnets having extensive recognition of the uniform grades in the global market, the grades of bonded NdFeB magnets are mainly based on the technology and standard of each manufacturer itself. For our company, the grades of bonded NdFeB magnets mostly include two parts, i.e. “HGT-“ + “number”. The left part “HGT” is our company’s short name. The right part “number” represents value of (BH)max (in CGS unit). The value varies from 2 to 12. In a few… Read More

Sintered NdFeB Magnet Grades

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Generally, the sintered NdFeB magnet grades are strings containing three parts, i.e. “N” + “number” + “letter”. The part “N” is the initial letter of neodymium, meaning it is a sintered neodymium iron boron magnet. So it is constant for all the neodymium magnet grades. The part “number” represents value of maximum energy product (BH)max (in CGS unit). The value varies from 28 to 52. The part “letter” reflects level of intrinsic coercivity Hcj. The levels include “M” (Hcj ≥… Read More

What are Rare Earth Permanent Magnets (REPMs)?

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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 REPMs. Compared with other types of permanent… Read More

What is a Permanent Magnet?

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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 the working temperature in various… Read More