Magnet Curie temperature on _ ndfeb strong magnet manufacturers
Summary of the Curie temperature is 320 ℃
380 ℃, but in fact ndfeb molecular structure has changed, when heated to reach in theory the Curie temperature of the magnetic force is back out.
I do the experiments of ndfeb heat resistance is 100 degrees, when heated to 100 degrees or so began to drop magnetic, but speed does not open, clear rapid decline after 150 degrees, 150 degrees 20 minutes magnetic base is back out.
After take back light magnetic ndfeb magnetization can only achieve about 50% of the original.
The phenomenon of black and surface oxidation.
Come to our company to buy the magnet are the use of magnet temperature concepts are vague, we must make it clear, of course, the problem is not understand in a few words can say, involves quantum mechanics, thermodynamics, solid mechanics, and many other aspects.
If only the company's form showed them they still don't feel intuitive.
I consulted many domestic and foreign data, probably due to this problem involves the scope is too large, no understand, I can't say completely understood, but still want to say a bit of my personal humble opinion.
Factory in permanent magnets are like to say their own magnet demagnetization never, but everything in the world is a sense of movement, not the permanent magnet demagnetization in fact does not exist, there are several reasons for demagnetization, but the intrinsic or internal magnet internal molecular thermal motion, the main reasons why thermal motion can change the magnetic orientation of magnetic domain, even let the disintegration of magnetic domain, after the collapse of the magnet is no magnetic.
Let the temperature of the magnetic domain decomposition is the Curie point, Curie point generally expressed in Tc, the temperature in our company sell the magnet ferrite is about 450 ℃, aluminum nickel and cobalt is about 860 ℃, ndfeb is 320 ℃
380 ℃, 450 ℃ - samarium cobalt
The discretion of the Curie point associated with the crystal structure of the magnet sintering to form, and impurities, cooling time environment, alloy composition ratio, sintering of the specific process (
Ingredients & ensp;
Ingot smelting system & rarr;
Milling & ensp;
Molding & ensp;
Sintering tempering & ensp;
Magnetic detection & ensp;
Grinding & ensp;
Pin cutting processing & ensp;
Electroplating & ensp;
The finished product.
The ingredients are the foundation, sintering tempering is the key)
Common ferrite magnets Curie temperature about 450 ℃, 320 - ndfeb magnet
860-380 ℃, aluminum nickel and cobalt
Working temperature: 80 ~ 100 ℃, ferrite magnet high-temperature models can reach 350 ℃;
Ndfeb magnets 60 ~ 200 ℃;
Samarium cobalt magnet 250 ~ 350 ℃;
Alnico magnets, 450 ~ 900 ℃ & ensp;
Working temperature is to point to in the temperature rise in the temperature interval magnetic force will decline, but most after cooling magnetic will recover.