Strong magnets generally refer to NdFeB magnets, which are mainly composed of an alloy of rare earth praseodymium and neodymium and common element iron. At present, this material is widely used in the market, but strong magnets often encounter weakening or disappearing magnetic force during use. We summarize the reasons for magnet demagnetization as follows:

1: Demagnetization or demagnetization of magnets after injection molding. The NdFeB N series has a minimum temperature resistance of 80°C, and sometimes injection molding is basically above 120°C, so a short injection of 2 to 3 seconds may cause partial demagnetization.

2: Demagnetization of magnets after hot pressing. Glass fiber board hot pressing is often used at a temperature of more than 150°C.

3: Demagnetization of magnets after oven baking.

4: The magnet material contains too many impurities, resulting in weak magnetism. This is the common result of most buyers who are greedy for cheap prices. Because they compare prices from three manufacturers and choose manufacturers with low prices. The customer clearly asked for N35, but the bad manufacturers with super low quotes used N28 and N33 materials. Customers should not expect to detect it. If the amount reaches 30K, can you use a fluxmeter to measure it slowly? (Demagnetization occurs in as short as 6 months, and as fast as two months). A reliable and stable supplier is really important. How can I use N35 materials for you without that price? Moreover, some merchants use magnets for packaging. Anyway, it’s okay as long as it can be absorbed. The material is garbage.

5: Impact causes permanent demagnetization of magnets, such as high-frequency impact, etc. Be especially careful during transportation.

6: The material contains metal ions, which causes the magnet to powderize.

7: The magnetic force of the magnet itself disappears or the N/S changes in the high magnetic field environment (magnetizer demagnetizer).

To summarize the above demagnetization (demagnetization) reasons, there are basically 4 points: high temperature demagnetization, material demagnetization, high-frequency impact demagnetization, and high magnetic field demagnetization.