Disc Ferrite Magnet With Notched Y30BH
Ferrite magnets are widely used in a variety of motor equipment with rotors, such as motors and generators. Recently the demand for ferrite magnets with high performance is increasing day by day, it is generally believed in the production of high-performance ferrite magnets pre under-burnt clinker must achieve Y30H - 1 above levels, namely remanent magnetism 3850 ~ 4100 g, coercive force of 3000 ~ 3375 oe, magnetic energy product 3.5 ~ 4.06 MGOe above.
At present, there are several ways to manufacture ferrite magnets including iron scale:
1. Dry grinding, dry grinding, oxidation and sintering. The method, in turn, the drying fish scale, iron scale, dry mixing, fine grinding is in the anhydrous state fine grinding materials, the raw material for the fine after the mold balling, ball after oxidation, the oxidation of raw materials will be burned into ferrite magnets under-burnt clinker. The magnetic properties of ferrite magnets prepared by this method can be 3800 ~ 3950G residual magnetism, 2,600 ~ 2900Oe coercive force, 3.4 ~ 3.6mgoe magnetic energy, which cannot reach the standard of y30h-1 completely. The main deficiency lies in the dry mixing fine grinding can not uniform ingredients is very difficult to further grinding fine iron scales to 3 micron, lead to the raw material of bivalent iron oxide is difficult, can affect the magnetic pre under-burnt clinker.
2. Wet grinding, wet grinding, oxidation and sintering. The manufacturing method is successively made by wet grinding iron scales, fine grinding of wet mixing materials, dry slurry, oxidation and sintering to form ferrite magnets pre-firing materials. The magnetic properties of ferrite magnets prepared by this method can be residual magnetism of 3750 ~ 3800G, coercive force of 2550 ~ 2600Oe, magnetic energy product of 3.0 ~ 3.3MGOe, which is lower than the standard of y30h-1 and slightly worse than that of method 1. The reason is that it is difficult to oxidize ferric iron ions in the raw materials due to the large amount of powder during sintering, which affects the magnetic energy of the pre-fired materials.
3. This method is used to make ferrite magnets pre-fired by drying iron scales, dry ground iron scales, iron oxide scales, ingredients, mixing materials, sintering and cooling. The method can be used to produce pre-firing ferrite magnets that meet the y30h-1 standard, but the fixed investment is large and the cost is high due to the need to add special kiln for iron oxide scale.
The manufacturing method of ferrite magnet prefiring is as follows:
(1) grind iron scale, the total iron content of iron scale is 72% ~ 75%.
(2) the wet mix is finely ground with at least one of strontium carbonate, barium carbonate, calcium carbonate and kaolin added to the ground iron scale after grinding and mixed with fine grinding.
(3) remove water from finely ground materials.
(4) make the ball from the raw material after water removal.
(5) dry and oxidize the raw materials after pelleting.
(6) the dry and oxidized materials are burned into ferrite magnets.