Horizon Magnetics has been focusing on the development and production of high end series of NdFeB and SmCo rare earth permanent magnets, which are widely used in permanent magnet motors and generators.
Due to their advantage, rare earth magnets have become one of the most important components of permanent magnet motors and generators, whose performance and life time mainly depends on the quality of magnets. Generally speaking, the working environment to motors and generators is very harsh. In order to adapt to this working environment, we have been devoting ourselves to research and develope NdFeB and SmCo rare earth magnets specially used for permanent magnet motors and generators since its foundation. For this application, the magnets are availabe in a wide range of shapes such as block, ring, segment, loaf, wedge, etc.
1) Featured NdFeB
Currently we are producing serials of high end grades, like H, SH, UH, EH and AH for NdFeB with following three characteristics:
- High intrinsic coercivity Hcj: high to >35kOe (>2785 kA/m) which increases magnets demagnetizing resistance
- Low reversible temperature coefficients: low to α(Br)< -0.1%/ºC and β(Hcj)< -0.5%/ºC which increases magnets temperature stability
- Low weight loss: low to 2~5mg/cm2 in HAST testing condition: 130ºC, 95% RH, 2.7 ATM, 20 days which increases magnets corrosion resistance
Although the low weight loss material improves its corrosion resistance, the coating is still often required by customers. If customers require coating, we suggest magnets be phosphated or passivated. However, more and more customers change to use magnets without any coating, because uncoated magnets have much better glue cohesiveness than coated magnets.
2) Featured SmCo
In fact, the above three characteristics mentioned for NdFeB is lower than that of SmCo. Our SmCo of grade 28 and 30 is ideal for the application of permanent magnet motors and generators. However, in the past the higher price and lower magnetic properties of SmCo limited its wider use. Since late 2010, the change began to happen due to the huge rise of rare earth price which caused most NdFeB to become more expensive than SmCo. Many customers are switching magnets from NdFeB especially of grade UH, EH and AH to SmCo of grade 28 or 30.
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