Permanent Magnet Materials

Permanent magnet lodestones contain magnetite, a hard, crystalline iron ferrite mineral that derives its magnetism from the effect the earth’s magnetic field has on it. Various steel alloys can also be magnetized. The first big step in developing more effective permanent magnet materials came in the 1930s with the development of Alnico alloy magnets. These magnets take their name from the chemical symbols for the aluminum-nickel-cobalt elements used to make the alloy. Once magnetized, Alnico magnets have between 5 and 17 times the magnetic force of magnetite.

Ceramic permanent magnets are made from finely powdered barium ferrite or strontium ferrite formed under heat and pressure. Their magnetic strength is enhanced by aligning the powder particles with a strong magnetic field during forming. Ceramic magnets are comparable to Alnico magnets in terms of magnetic force and have the advantage of being able to be pressed into various shapes without significant machining.Magnet Materials

Flexible permanent magnets are made from powdered barium ferrite or strontium ferrite mixed in a binding material like rubber or a flexible plastic like polyvinyl chloride.

In the 1970s, researchers developed permanent magnets made from powdered samarium cobalt fused under heat. These magnets take advantage of the fact that the arrangement of the groups of atoms, called magnetic domains, in the hexagonal crystals of this material tend to be magnetically aligned. Because of this natural alignment, samarium-cobalt magnets can be made to produce magnetic forces 50 times stronger than magnetite. Headphones for small, personal stereo systems use samarium-cobalt permanent magnets. Samarium-cobalt magnets also have the advantage of being able to operate in higher temperatures than other permanent magnets without losing their magnetic strength.

Similar permanent magnets were made in the 1980s using powdered neodymium iron boron which produces magnetic forces almost 75 times stronger than magnetite. These are the most powerful permanent magnets commercially available today.

Electromagnet Materials

Pure iron and iron alloys are most commonly used in electromagnets. Silicon iron and specially treated iron-cobalt alloys are used in low-frequency power transformers.

A special iron oxide, called a gamma iron oxide, is often used in the manufacture of magnetic tapes for sound and data recording. Other materials for this application include:
The above illustrations show a typical powdered metallurgy process used to produce powerful neodymium-iron-boron permanent magnets.
The above illustrations show a typical powdered metallurgy process used to produce powerful neodymium-iron-boron permanent magnets.
cobalt-modified iron oxides and chromium dioxide. The material is finely ground and coated on a thin polyester plastic film.

Other Magnetic Materials

Magnetic fluids can be made by encapsulating powdered barium ferrite particles in a single layer of molecules of a long-chain polymer plastic. The particles are then held in suspension in a liquid like water or oil. Because of the plastic encapsulation, the magnetic particles slide over each other with almost no friction. The particles are so small that normal thermal agitation in the liquid keeps the particles from settling. Magnetic fluids are used in several applications

Magnet as sealants, lubricants, or vibration damping materials.

Tile NdFeB Magnet for Motor Ni N30H

Tile NdFeB Magnet for Motor Ni N30H

Tile NdFeB Magnet for Motor Ni N30H, Powerful Segment NdFeB Permanent Magnet, Motor Rotor Generator and Actuator NIB Magnet, super strong neodymium iron boron arc tile magnets, Sintered Neo Magnetic Arc, extremely strong rare earth arc neodymium magnet China Supplier Manufacturer Exporter Factory Tile NdFeB Magnet for Motor Ni N30H Technical Specifications: Item: NSGN30H-24 Grade: N30H […]

 

Arc NdFeB Magnet for Motor Ni N45M

Arc NdFeB Magnet for Motor Ni N45M

Arc NdFeB Magnet for Motor Ni N45M, Powerful Segment NdFeB Permanent Magnet, Motor Rotor Generator and Actuator NIB Magnet, super strong neodymium iron boron arc tile magnets, Sintered Neo Magnetic Arc, extremely strong rare earth arc neodymium magnet China Supplier Manufacturer Exporter Factory Arc NdFeB Magnet for Motor Ni N45M Technical Specifications: Item: NSGN45M-23 Grade: N45M […]

 

NdFeB Segment Magnet for Motor Ni N45H

NdFeB Segment Magnets for Motor Ni N45H

NdFeB Segment Magnets for Motor Ni N45H, Powerful Segment NdFeB Permanent Magnet, Motor Rotor Generator and Actuator NIB Magnet, super strong neodymium iron boron arc tile magnets, Sintered Neo Magnetic Arc, extremely strong rare earth arc neodymium magnet China Supplier Manufacturer Exporter Factory NdFeB Segment Magnets for Motor Ni N45H Technical Specifications: Item: NSGN45H-22 Grade: N45H […]

 

Segment Generator Neodymium Magnet Ni N45

Segment Generator Neodymium Magnet Ni N45

Segment Generator Neodymium Magnet Ni N45, Powerful Segment NdFeB Permanent Magnet, Motor Rotor Generator and Actuator NIB Magnet, super strong neodymium iron boron arc tile magnets, Sintered Neo Magnetic Arc, extremely strong rare earth arc neodymium magnet China Supplier Manufacturer Exporter Factory Segment Generator Neodymium Magnet Ni N45 Technical Specifications: Item: NSGN45-21 Grade: N45 Material: Neodymium […]