Permanent Magnets

The word – magnet is always related the concept of attraction. In the physical world, it’s a force where two or more objects pulling towards each other, which we refer to as magnetic force. Abstractly, magnet can be a person, a thing or a place that is attractive to a person. However, just like a thing can lose its shine or a person his charm with time, magnets can lose its magnetism. That’s where permanent magnets make a difference. 

By definition, a permanent magnet is a magnet that never loses its magnetic field. The first permanent magnet in history is called a loadstone. It is a naturally magnetized rock mainly composed of Fe3O4.

a stone, world-first permanent magnet

AlNiCo Magnets - 1st Generation Permanent Magnet

In the modern history, the first permanent magnet ever developed and commercially used is called AlNiCo. AlNiCo was developed in the early 1930s and was then used in military electronic applications during World War II. AlNiCo magnets are divided into cast AlNiCo and sintered AlNiCo. Alnico offers high magnetic field. But it has a low coercive force, which mean it can be easily demagnetized.

AlNiCo Ring Magnets
AlNiCo horseshoe magnet
AlNiCo Cylinder
AlNiCo holding magnet

Ceramic magnet (Hard ferrite or ferrite magnet) - 2nd Generation Permanent Magnet

In the 1960s, hard ferrite or ceramic magnet was developed and quickly gained popularity in the world industry. It is a low-cost permanent magnet material made primarily of strontium carbonate and iron oxide (Fe2O3). Due to its good resistance to demagnetization and excellent corrosion resistance, ceramic magnets gained its market very quickly. Nowadays, if measuring by weight, over 70% of the magnets commercially used are hard ferrite/ceramic magnets.

Ceramic disc magnet
Ceramic ring magnet
6"x4"x1"ceramic block

Samarium Cobalt - 1st and 2nd Generation Rare Earth Magnet

A few years later, something called rare earth magnet was developed. It was Samarium-Cobalt that opened the era of rare earth magnets. This permanent magnet material has two series: SmCo5 and Sm2Co17. In addition to their excellent magnetic strength, they can withstand high temperature.

SmCo arc magnets
SmCo arc magnets
Samarium Cobalt Magnets
SmCo cylinder magnets
SmCo ring magnets

Neodymium magnet (NdFeB magnet) - 3rd Generation Rare Earth Magnet)

In the early 1980s, a brand-new rare-earth magnet called neodymium magnet (NdFeB) was independently developed by Japanese and American. NdFeB magnet exhibits a much stronger magnetic strength than any previous permanent magnet material. It has enabled miniaturization in design and introduced more possibilities in modern technology.

neodymium magnets
neodymium disc magnets
neo disc magents
neo countersunk magnet
neodymium ring magnet
neo ring magnet
neo bar magnet
pot magnet
NdFeB pot magnet

About Tengye: Tengye Magnetic supplies finest permanent magnet materials and custom magnetic assemblies to world industry. We work closely with our customer from designing stage to mass production. 

error: Content is protected !!

Inquiry Form