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Features: Isotropic, Multiple Poles, Magnetizing Along Any Axis, High
Energy.
A recently introduced material in the
NdFeB family is the bonded NdFeB with energy products currently
in 3 - 12 MGOe range. Bonded NdFeB magnets could be made to close
tolerances right off the tool, minimizing the need for finish
machining.
Bonded neodymium-iron-boron magnets
are made by patented materials -- MQP family. These materials
are produced from fast quenching processing. Molten Nd
2Fe14B
alloy flows under pressure onto a chilled rotating wheel. The
alloy is instantaneously cooled at a rate of about one million
º C/second. This process forms flakes of NdFeB. The flakes
are then crushed into 200-micron particle-sized powder. These
fine grain size isotropic NdFeB particles have high thermal stability
in terms of flux density and intrinsic coercivity. The annealed
powder can be combined with a variety of plastics or polymers,
epoxy resin for injection or compression molding. The blend is
fed into mold in a cold compacting process to form the magnets
which are subsequently oven-cured. This process permits magnet
shapes and dimensions -- ± 0.002" or 0.05 mm in tolerances
-- that were previously impractical or impossible.
Our bonded magnets are coated by electrophoresis
coating processing using different
epoxy resins
to meet our customers' requirement. The thickness of the epoxy
resin coating can be controlled to 15 to 35 microns. One or two
coating layers may be applied depended on different working environments.
These coated magnets could survive in the salt fog spray test
(5 % NaCl, 35º C) for 200 to 600 hours. The coating could
be grey or black in color. The finished coating is smooth,
free of voids and pin-holes. Nickel-coating and Zinc-coating are
also available for your selection.
The finished magnet parts might be
magnetized along any axis and with multiple poles on any surface
because of their isotropic nature, though special magnetizing
fixtures must be constructed for this.
The Curie temperature, Tc, of Bonded
NdFeB magnets varies from 305º C to 470º C depended
on powders used.
Systems
International could custom-make
a variety of bonded NdFeB magnets to meet our customers' special
needs. They could be a magnet ring -- a large ring with a outer
diameter up to 8" or 200mm; or a small ring with wall
thickness as
thin as 0.04" or 1.0mm. They also could be arcs, blocks,
disks, etc.
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