Permanent magnet points two categories: the first major categories: metal alloy (including magnet nd-fe-b magnet
, samarium cobalt permanent magnet (
, aluminum nickel and cobalt permanent magnet (
The second categories: ferrite permanent magnet,
1, nd-fe-b magnet, it is found that commercialization of the highest performance magnets, known as magnetic king, has the extremely high magnetic to its maximum magnetic energy product (
Above ferrite (
More than 10 times.
Machining properties of its itself is also quite good.
Working temperature up to 200 degrees Celsius.
And the quality of a material is solid, stable performance, good cost performance, so its application is very extensive.
But because of its chemical activity is very strong, so you have to handle with polish on the surface layer.
Such as nickel plating, zinc, electrophoresis, passivation, etc. )
2, ferrite permanent magnet, its main raw materials including BaFe12O19 and SrFe12O19.
Manufactured by ceramic technology, the quality of a material is hard, brittle material, because of the ferrite permanent magnet has good temperature resistance, low cost, moderate performance, has become the most widely applied permanent magnets.
3, aluminum nickel and cobalt permanent magnet, is made from aluminum, nickel, cobalt, iron and other trace metal elements constitute a kind of alloy.
Casting process can be processed into different sizes and shapes, machinability is good.
Casting aluminum nickel and cobalt permanent magnet has the lowest temperature coefficient is reversible, working temperature can be as high as 600 degrees Celsius above.
Alnico permanent magnet products are widely used in all kinds of instruments and meters and other application fields.
4, samarium cobalt (
According to the composition of different divided into SmCo5 and Sm2Co17.
Because its material is expensive and make its development was restricted.
Samarium cobalt (
As a rare earth permanent magnet, not only have higher magnetic energy product (
And reliable coercive force and good temperature characteristic.
Compared with the nd-fe-b magnets, samarium cobalt permanent magnet is more suitable for working in high temperature environment.
The history of the permanent magnet, with the development of the society, the application of permanent magnet is becoming more and more widely, from high-tech products to the most simple packaging, the most widely used or nd-fe-b magnets and ferrite permanent magnet.
From the development history of permanent magnet, the end of the 19th century in the early 20th century, people mainly use carbon, steel, tungsten, cobalt chromium steel and steel for permanent magnetic material.
In the late 1930 s, aluminum nickel and cobalt permanent magnet successful development, makes the magnet the large-scale application of possible.
50 s, the emergence of barium ferrite magnets, reduces the cost of permanent magnets, and to broaden the application scope of permanent magnet materials to high frequency field.
To 60 s, samarium cobalt permanent magnet, is for the application of the magnet has opened up a new era.
In 1967, the United States at the university of Dayton Strnat etc. , to develop into a samarium cobalt magnet, marks the arrival of the era of rare earth magnets.
So far, ten permanent magnet has experienced the first generation of SmCo5, dilute the second generation Sm2Co17 precipitation hardening type, development to the third generation of Nd -
B permanent magnet materials.
Far the largest permanent magnet ferrite magnet is still the dosage, but the ndfeb magnet production is much more than ferrite permanent magnet, ndfeb magnet production has developed into a big industry.
Magnetic size is: nd-fe-b magnets, samarium cobalt permanent magnet, alnico permanent magnets, ferrite permanent magnet.
Magnet technology: nd-fe-b magnets, samarium cobalt permanent magnet, alnico permanent magnets, ferrite permanent magnet technology is also different.
Tell from technology, sintered nd-fe-b magnet and bonding nd-fe-b magnet.