65results about How to "Large and uniform crystal grains" patented technology

The invention discloses a tantalum-based ferrite magnetic core material used for transformer, which comprises a main material and an additive, the main material comprises the following components according to mol ratio: 57.1-64mol of Fe2O3, 16.2-20mol of manganese oxide, 10.1-15mol of zinc oxide, 4-5.2mol of copper oxide, 0.2-1 mol of zinc borate, 1-1.3mol of barium oxide and 0.01-0.02mol of rare earth composite magnetic conductive powder; and the additive comprises the following components according to weight ratio of the additive in the ferrite magnetic core material: 30-50ppm of aluminium triphosphate, 10-20ppm of titanium tetrachloride and 40-50ppm of silicon powder. The magnetic energy product of the rare earth composite magnetic conductive powder in the ferrite magnetic core material is high, and magnetic performance is stable, preparation method is simple, and the finished product has the characteristics of high crystal boundary resistivity, low porosity and large crystal grain.

The invention discloses a method for manufacturing a ferromagnetic core containing modified aluminum nitride. The method includes steps of performing pre-sintering on a mixture A comprising Fe<2>O<3>, MoO, ceramic powder, boron, titanium, aluminum hydroxide, the modified aluminum nitride and bentonite and a mixture B comprising SiO<2>, Nb<2>O<5>, yttrium oxide, tantalum oxide, Al, tin, vanadium and rubidium; sequentially performing grinding, mixing and pulping, powder spray-drying, green body pressing and sintering processes on the mixture A and the mixture B to obtain the ferromagnetic core. The total weight of the mixture B is equivalent to that of the mixture A. The method has the advantages that owing to an optimized formulation design and the sintering process, the initial permeability of a product manufactured by the method is 20000, cracking of the sintered product is little, the qualified rate of the product reaches 94.5% at least, the product is high in grain boundary resistivity and low in porosity, crystal grains of the product are large and uniform, the impendence characteristic of the product in a high-frequency range is excellent, various electromagnetic properties of the product are stable, and the ferromagnetic core product is applicable to various electronic fields.

The invention discloses a method for manufacturing a lithium-rich ferromagnetic core. The method includes steps of performing pre-sintering on a mixture A comprising Fe<3>O<4>, ZnO, lead tetroxide, zirconium fluoride, barium carbonate, lithium, palladium oxide and antimony trioxide and a mixture B comprising iron powder, Bi<2>O<3>, molybdenum, tungsten, gallium, zirconium oxide, chromium oxide and potassium oxide; sequentially performing grinding, mixing and pulping, powder spray-drying, green body pressing and sintering processes on the mixture A and the mixture B to obtain the lithium-rich ferromagnetic core. The total weight of the mixture B is equivalent to that of the mixture A. The method has the advantages that owing to an optimized formulation design and the sintering process, the initial permeability of a product manufactured by the method is 18800, cracking of the sintered product is little, the qualified rate of the product reaches 91.5% at least, the product is high in grain boundary resistivity and low in porosity, crystal grains of the product are large and uniform, the impendence characteristic of the product in a high-frequency range is excellent, various electromagnetic properties of the product are stable, and the ferromagnetic core product is applicable to various electronic fields.

The invention discloses a nickel-based ferrite magnetic core material for a transformer, which includes main materials and additives, and the main materials include: 57-63.6mol of Fe2O3, 17.0-22mol of manganese oxide, 10.2-16 mol of zinc oxide, 0.01-0.03 mol of stainless steel powder, 0.2-0.3 mol of barium sulfate, 0.01-0.02 mol of rare earth composite magnetically permeable powder; the additives include according to the weight ratio of the ferrite core material : Molybdenum powder of 80-90ppm, lithium nitride of 40-60ppm, magnesium hydroxide of 70-90ppm, the magnetic energy product of the rare earth composite magnetic conductive powder added to the ferrite magnetic core material of the present invention is high, magnetically stable, and the preparation method is simple , The finished product has the characteristics of high grain boundary resistivity, low porosity, large and uniform grains.

The invention discloses a method for manufacturing a ferromagnetic core loaded with boric oxide. The method includes steps of performing pre-sintering on a mixture A comprising Fe<3>O<4>, manganese oxide, the boric oxide, zirconium fluoride, nickel oxide, borax, ferric oxide powder and aluminum powder and a mixture B comprising tantalum, titanium, tungsten, MoO<3>, Nb<2>O<5>, magnesium carbonate, lanthanum oxide and barium carbonate; sequentially performing grinding, mixing and pulping, powder spray-drying, green body pressing and sintering processes on the mixture A and the mixture B to obtain the ferromagnetic core. The total weight of the mixture B is equivalent to that of the mixture A. The method has the advantages that owing to an optimized formulation design and the sintering process, the initial permeability of a product manufactured by the method is 12500, cracking of the sintered product is little, the qualified rate of the product reaches 93.0% at least, the product is high in grain boundary resistivity and low in porosity, crystal grains of the product are large and uniform, the impendence characteristic of the product in a high-frequency range is excellent, various electromagnetic properties of the product are stable, and the ferromagnetic core product is applicable to various electronic fields.

The invention discloses a method for manufacturing a ferromagnetic core containing modified nano-carbon. The method includes steps of performing pre-sintering on a mixture A comprising Fe<2>O<3>, MnO, ceramic powder, aluminum, zinc, niobium, the modified nano-carbon and straw ash and a mixture B comprising Bi<2>O<3>, CaCO<3>, nickel oxide, palladium oxide, scandium oxide, lanthanum oxide, Si and B; sequentially performing grinding, mixing and pulping, powder spray-drying, green body pressing and sintering processes on the mixture A and the mixture B to obtain the ferromagnetic core. The total weight of the mixture is equivalent to that of the mixture A. The method has the advantages that owing to an optimized formulation design and the sintering process, the initial permeability of a product manufactured by the method is 18000, cracking of the sintered product is little, the qualified rate of the product reaches 97% at least, the product is high in grain boundary resistivity and low in porosity, crystal grains of the product are large and uniform, the impendence characteristic of the product in a high-frequency range is excellent, various electromagnetic properties of the product are stable, and the ferromagnetic core product is applicable to various electronic fields.