Basic Characteristics of Rare Earth Magnets

Because of its own composition, magnets have many characteristics, such as directivity, mutual exclusion and attractiveness, indivisibility, magnetic field characteristics and so on.

When two magnets are close to each other, they repel each other with the same polarity and attract each other with the different polarity. It can be inferred that the two ends of the needle magnet which can rotate freely can point to the north-south direction of the earth because the earth itself is a large magnet. The north pole of the earth magnet is near the geographic South pole, and the south pole of the earth magnet is near the geographic North pole. The deflection angle between the geomagnetic North Pole and the geographic North Pole is called the magnetic deflection angle. Magnets also have the inseparability of two poles. The same magnet always has two poles at the same time, the Antarctic and the Arctic. The long bar magnet is cut into several short magnets, each of which has both N and S poles. The existence of unipolar magnetic rest has not been found theoretically and experimentally.

Another fundamental characteristic of magnets is the ability to generate magnetic fields. A rare earth magnet always generates a magnetic field in the space around it. The magnetic field produced by a magnet is directional. Always start at the N pole and then go back to the S pole. The same is true inside the magnet. The directivity of a magnet can be achieved by hanging a small magnet in half-air with a cotton thread, so that it can rotate freely. When it stops, its two ends point south and North respectively.

How to choose Nd-Fe-B high temperature resistant magnets at different temperatures?

Generally, neodymium magnets will demagnetize when their working temperature is above 80 degrees, but the temperature of some special occasions is very high, far higher than 80 degrees. How to choose neodymium high-temperature magnets?

The specific grades are as follows:

1. M-band Nd-Fe-B high temperature resistant magnet can be selected at working temperature between 80 and 100 degrees.

2. H-band Nd-Fe-B high temperature resistant magnet can be selected at working temperature between 100 and 120 degrees.

3. SH Nd-Fe-B high temperature resistant magnet can be selected at working temperature between 120 and 150 degrees.

4. UH Nd-Fe-B high temperature resistant magnet can be selected at working temperature between 150 and 180 degrees.

5. EH Nd-Fe-B high temperature resistant magnet can be selected at working temperature between 180 and 200 degrees.

6. AH Nd-Fe-B high temperature resistant magnet can be selected at the working temperature between 200 and 230 degrees.

Secondly, Samarium cobalt high temperature resistant magnets are selected between 230 and 350 degrees of working temperature.

The specific grades are as follows:

1. When the working temperature is between 230 degrees and 250 degrees, we can choose 1: 5 samarium cobalt.

2. When the working temperature is between 250 degrees and 350 degrees, we can choose 2:17 samarium cobalt.

3. Aluminum-nickel-cobalt magnets are currently available only for high temperature resistant magnets operating at temperatures above 350 degrees.