Powerful magnets generally refer to NdFeB strong magnetic magnets, which are mainly composed of alloys of rare earth praseodymium, neodymium and common element iron. This material is currently widely used in the market, but powerful magnets often encounter magnetic weakening or disappearance during use. It often happens. We summarize the reasons for magnet demagnetization as follows:
1. Magnet injection molding will demagnetize or demagnetize. The minimum temperature resistance of the NdFeB strong magnetic magnets is 80°C, and sometimes the injection molding is basically above 120°C, so a short period of 2 seconds to 3 seconds of injection molding may cause partial demagnetization. Imagine.
2. The NdFeB strong magnetic magnet is demagnetized after hot pressing. Glass fiber plates are often used for hot pressing at temperatures above 150°C.
3. The magnet demagnetizes after baking in the oven.
4. The NdFeB strong magnetic magnet contains too many impurities, resulting in weak magnetism. This is the common result of most cheap buyers. Because when it comes to quotations, shop around and choose the manufacturer with the lowest quotation. Obviously the customer requested the N35 grade, but the defective manufacturer with extremely low quotations used N28 and N33 materials. The customer should not expect to be able to detect it. If the quantity reaches 30K, should it be measured slowly with a flux meter? A trustworthy and stable supplier is really important. How can I make it for you using N35 materials without that price? Moreover, some merchant magnets are used for packaging. Anyway, as long as they can be sucked, the materials are just garbage.
To sum up, 90% of the above reasons for demagnetization of NdFeB strong magnetic magnet are basically 4 points: high temperature demagnetization, demagnetization due to problems with the material itself, high frequency impact demagnetization, and high magnetic field demagnetization.
