The magnets are composed of neodymium, iron, boron and a few transition metals.
Sintered ndfeb magnets are the most powerful permanent magnets available today. It has a combination of very high remanence and coercivity, and comes with a wide range of grades, sizes and shapes such as rings, blocks, discs and segments. With its excellent magnetic characteristics and abundant raw material, ndfeb magnet offers more flexibility in designing of new or replace the traditional magnet materials such as ferrite, alnico and sm-co to achieve high efficiency, low cost and more compact devices.
Ndfeb magnet is highly susceptible to corrosion and coating is always necessary. Frequently they are plated in nickel, zinc, tin and epoxy resin.
Ndfeb magnet
Available in a very wide range of shapes, sizes and grades. Ndfeb magnets was primarily for voice coil motors (vcm's) in hard disk drives
Aother applications include high performance motors, brushless dc motors, magnetic separation, magnetic resonance imaging, sensors and loudspeakers.
Neodymium iron boron ( NdFeB) is a type of rare earth magnetic material.
NdFeB is the most advanced commercialized permanent magnet material available today.
This material has similar properties as the samarium cobalt except that it is more easily oxidized
and generally doesn't have the same temperature resistance.
However, NdFeB magnets have the highest energy products approaching 52MGOe and are
mechanically stronger than samarium cobalt magents. NdFeB material is more costly by weight than
ceramic or alnico but produces the highest amount of flux per unit of volume or mass amking it very economical for many applicantions. Their high energy products lend themselves to comnpact designs
that result in innovative applications and lower manufacturing costs.
Unprotected NdFeB magnets are subject to corronsion. Surface treatments has ben developed that
allow them to be used in most applications. These treatments include copper, silver,, gold, nickel,
zinc and tin plating and epoxy resin coating.
Beneficial characteristics of NdFeB magnets include their very high energy product, very high
coercive force, and moderate temperature stability. Drawbacks include lower mechanical strength,
and low corrosion resistance when not properly coated or plated.
Magnetic Grades and Temperature:
The Grade of a magent directly refers to the Maximum Energy Product of the material that composes the magnet. It in no way refers to the physical properties of the magnet. Grade is generally used to describe
how "strong" a permanent magnet material is. The energy products is specified in the unites Gauss Oersted.
One MGOe is 1,000,000 Gauss Obersted. A grade forty (N40) would have a Maximum Energy Product of 40 MGOe.The higher the grade the "stronger" the magnet.
Magnetic materials have a wide range of working temperatures. The following chart the various materials and their maximum working temperature. NdFeB material
Neodymium magnet (also known as NdFeB, NIB or Neo magnet), the most widely used type of rare-earth magnet, is a permanent magnet made from an alloy of neodymium, iron and boron to form the Nd2Fe14B tetragonal crystalline structure
