Many customers who are in contact with magnets may not know much about the ferrite part, and there should be more questions about how long it can be stored.
Ferrite, also known as permanent magnet ferrite, chemical name is iron tetroxide, it is already an oxide of iron, and it is difficult to be oxidized again. For the magnetic ring, its characteristics are long-term, and there will be no deterioration at all, but after a long time, there will be some powder left on the surface. This is a normal phenomenon and does not hinder its characteristics.
Everyone knows that ferrite magnets are made of a variety of magnetic materials. Naturally, after a long time, powder will appear on the body, which is what we call oxidation in our industry, but this does not affect its magnetic properties and impedance characteristics at all, once the magnetic ring is exposed to moisture, it will be easily oxidized, especially in humid weather, if the packaging magnetic ring is not sealed well, the water will run into the carton, which will also cause the magnetic ring to oxidize.
Many people asked back, isn't the magnetic ring just washed with water to clean the surface? Why are you afraid of water? Of course, the magnetic ring uses water to wash off the dirt on the surface, but after cleaning, the magnetic ring will enter the oven to dry the water, so the newly made magnetic ring will not oxidize at all, and it is just The surface of the magnetic ring after washing is bright and shiny.
The role of ferrite magnets in many fields is very large, especially in some modern magnetic research, the magnetism of ferrite is also relatively large in modern electronic and electrical production, and can achieve certain goals through magnetic force, In order to better promote the progress of production, the magnetic force has been used in the magnetic tape for a long time. Today, let's learn about the principle of using the magnetic force in the magnetic tape!
After the hard magnetic material is magnetized, there is still residual magnetism. The strength and direction of remanence depend on the strength and direction of magnetism during magnetization. Audio tape is composed of tape base, adhesive and magnetic powder layer. The tape base is generally made of polycarbonate or vinyl chloride. The magnetic powder is r-Fe2O3 or CrO2 fine powder with strong remanence.
When recording, the current corresponding to the sound change is amplified and sent to the coil of the recording head, so that a concentrated magnetic field is generated in the gap of the iron core of the head.
As the coil current changes, the direction and strength of the ferrite magnet's magnetic field also changes accordingly. When the tape passes through the head gap at a constant speed, the magnetic field passes through the tape and magnetizes it. Since the magnetic tape leaves the magnetic head with corresponding residual magnetism, its polarity and intensity correspond to the original sound. The tape is constantly moving, and the sound is constantly being recorded on the tape.
When playing, feed the recorded tape close to the gap of the playback head at the same speed as when recording. The magnetic head core is made of high permeability ferrite soft magnetic material, which has very little resistance to magnetic flux. Therefore, the audio residual magnetic flux recorded on the magnetic tape is easy to form a loop through the magnetic head iron core. The residual magnetic flux on the magnetic tape induces an induced electromotive force on the playback head coil that has the same changing law as the residual magnetic flux. After being amplified by the playback amplifier, it is sent to push the speaker, and the audio signal recorded on the tape will be restored to the original sound.