Rubber coated magnets are widely selected for holding application because of their unique feature of protecting holding surfaces while offer great holding force. Most of them need a working life for 10 years or 20 years more. On basis of this, many users are curious about that will the magnet force keep unchanged for such a long time?
Frequently asked questions about Custom Rubber Magnets——Will the Neodymium Magnet force could keep unchanged for 30 years?
The Neodymium Magnet is widely used for generate holding force in coated magnets for sale from WZ Magnetics, so it makes sense to study how the magnetic energy changes over the times.
The Zhong Ke San Huan reveals the mistery through a well-designed 12-year long experiment. The researchers put 8pcs uncoated neodymium magnet samples (Hcj=1240kA/m, 10.2mm length) under 22°C~28°C environment with full exposure to air for continuous 12 years. They test the magnetic flux value and carefully observed the samples at the same time every year.
Rare-earth Permanent Magnet Materials by Hu Boping, Rao Xiaolei, Wang Yizhong 2017
All the measured data showed that in the first 6 years, there is almost no any magnetic loss can be found, but after that, an obvious right-lower tilted line indicates an ongoing trend of magnetic loss. We can come to a conclusion that less than 1% magnetic loss can be seen in 30 years and 2% magnetic loss can be seen in 150 years if we extend the line based on its slope.
Remember that, these NdFeB magnets are not coated while magnetic loss happens mainly from surface oxidation. That means neodymium with surface treatment will have a much better anti-oxidation feature. With these points and clues, we can easily draw a conclusion that even based on a really conservative estimate, the NdFeB magnets can be expected a lifetime of 30-50 years with magnetic loss of less than 1%.
So, use these rubber coated magnets at the temperature that corresponding to their Hcj and the magnetic force will not have a big change (more than 1%) in, at least for 30 years.
