A kind of niobium based ferrite core material for transformer
Technical field
The invention mainly relates to oxidate magnetic material and manufacture field, particularly relate to a kind of niobium based ferrite core material for transformer.
Background technology
Along with the communication technology and the digitized development of electronic product; soft magnetic ferrite and element are proposed new requirement; high-performance high permeability magnetic core is widely used in each type telecommunications and information stock, as the fields such as common-mode filter, pulsactor, current transformer, earth leakage protective device, insulating transformer, signal and pulse transformer are widely applied.Telecommunications industry needs FERRITE CORE to have low core loss and high magnetic permeability now, and to meet the miniaturization of present electric equipment and high efficiency requirement, existing magnetic core is difficult to meet above-mentioned requirements;
Its magnetic energy product of permanent-magnet material that rare earth prepares is up to 150 times, 3~5 times of Al-Ni-Co permanent magnet material of carbon steel
, 8~10 times of permanent-magnet ferrite, temperature coefficient is low, magnetic stability, and coercivity is up to 800 kilo-amperes/rice.It is mainly used in the magnetic system of low speed torque motor, startup motor, sensor, magnetic bearing etc..Nd-Fe-B permanent magnet material is third generation rare earth permanent-magnetic material, and its remanent magnetism, coercivity and maximum magnetic energy product are higher than the former, non-friable, has preferable mechanical performance, and alloy density is low, beneficially the lightness of magnetic element, slimming, small-sized and subminaturization.
Summary of the invention
The object of the invention is contemplated to make up the defect of prior art, it is provided that a kind of niobium based ferrite core material for transformer.
The present invention is achieved by the following technical solutions:
A kind of niobium based ferrite core material for transformer, it includes that major ingredient and additive, described major ingredient include according to mol ratio: Fe2O3,20.1-25 of 62-72.3 mol
The manganese oxide of mol, 10-13.5
The zinc oxide of mol, the titanium dioxide of 0.6-0.8mol, the barium monoxide of 0.1-0.3 mol, the rare earth compounded magnetic conductive powder of 0.01-0.02 mol;Additive includes according to the mass ratio range accounting for described ferrite core material: the sodium metasilicate of 60-100ppm, the cobaltosic oxide of 20-60ppm, the magnesia of 70-100ppm;
The preparation of described rare earth compounded magnetic conductive powder comprises the following steps:
The preparation of premixed liquid:
Described premixed liquid is made up of the raw material of following weight parts: ammonium metavanadate 0.6-2, carboxymethylcellulose calcium 2-3, niobium pentaoxide 80-90, ethylene carbonate 1-2, water 200-300;
Carboxymethylcellulose calcium is joined in above-mentioned water, is heated to 60-70 DEG C, stir, add niobium pentaoxide, ammonium metavanadate, stir to normal temperature, add and remain each raw material, 200-300 rev/min of dispersed with stirring 10-20 minute, obtain premixed liquid;
It is the trimethylolpropane of 1-2:5-7:100, stearic acid, neodymia mixing by mass ratio, stirring mixing 30-40 minute at 58-65 DEG C, adding concentration is the acetic acid of 10-20%, 70-100 rev/min of dispersed with stirring 4-6 minute, add ammonium fluoride, stirring mixing 20-30 minute, adds premixed liquid, 400-500 rev/min of dispersed with stirring 1-2 hour, it is dried 20-30 minute at 80-100 DEG C, send into sintering furnace, sinter 4-6 hour at 300-350 DEG C, obtain described rare earth compounded magnetic conductive powder;
Described neodymia, acetic acid, the mol ratio of ammonium fluoride are 2-3:6-7:1-2;
Described niobium pentaoxide is 20-30:1 with the mass ratio of neodymia.
The preparation method of a kind of niobium based ferrite core material for transformer, comprises the following steps:
(1) above-mentioned major ingredient being sent into blending tank, 2500-3000 rev/min of stirring mixes 2-4 hour, sends into grinding pot, and being ground to fineness is 50-70 μm, adds the water of major ingredient weight 25-30%, the oleic acid of 2-3%, and high-speed stirred mixes, and obtains slurries;
(2) additive being sent into grinding pot, add the aluminium dihydrogen phosphate of weight of additive 1-2%, being ground to fineness is 60-100 μm;
(3) each raw material after above-mentioned process is mixed, stir, be spray-dried, be pressed into base, sintering, obtain the described niobium based ferrite core material for transformer.
The invention have the advantage that
The rare earth compounded magnetic conductive powder magnetic energy product that the ferrite core material of the present invention adds is high, magnetic stability, and preparation method is simple, and it is high that finished product has grain boundary resistance rate, and the porosity is low, mechanical performance is strong, crystal grain uniform feature greatly.
Detailed description of the invention
Embodiment 1
A kind of niobium based ferrite core material for transformer, it is characterised in that it includes that major ingredient and additive, described major ingredient include according to mol ratio: the Fe2O3 of 72.3 mol, 25
The manganese oxide of mol, 13.5
The zinc oxide of mol, the titanium dioxide of 0.8mol, the barium monoxide of 0.3 mol, the rare earth compounded magnetic conductive powder of 0.02 mol;Additive includes according to the mass ratio range accounting for described ferrite core material: the sodium metasilicate of 100ppm, the cobaltosic oxide of 60ppm, the magnesia of 100ppm;
The preparation of described rare earth compounded magnetic conductive powder comprises the following steps:
The preparation of premixed liquid:
Described premixed liquid is made up of the raw material of following weight parts: ammonium metavanadate 0.6-, carboxymethylcellulose calcium 2, niobium pentaoxide 90, ethylene carbonate 2, water 300;
Carboxymethylcellulose calcium is joined in above-mentioned water, is heated to 70 DEG C, stirs, add niobium pentaoxide, ammonium metavanadate, stir to normal temperature, add and remain each raw material, 300 revs/min of dispersed with stirring 20 minutes, obtain premixed liquid;
It is the trimethylolpropane of 2:5:100, stearic acid, neodymia mixing by mass ratio, stirring mixing 40 minutes at 65 DEG C, adding concentration is the acetic acid of 10-20%, 100 revs/min of dispersed with stirring 6 minutes, add ammonium fluoride, stirring mixing 30 minutes, adds premixed liquid, 500 revs/min of dispersed with stirring 2 hours, it is dried 30 minutes at 100 DEG C, send into sintering furnace, sinter 4 hours at 350 DEG C, obtain described rare earth compounded magnetic conductive powder;
Described neodymia, acetic acid, the mol ratio of ammonium fluoride are 2:7:2;
Described niobium pentaoxide is 30:1 with the mass ratio of neodymia.
The preparation method of a kind of niobium based ferrite core material for transformer, comprises the following steps:
(1) above-mentioned major ingredient being sent into blending tank, 3000 revs/min of stirrings mix 2 hours, send into grinding pot, and being ground to fineness is 70 μm, add the water of major ingredient weight 30%, the oleic acid of 2%, and high-speed stirred mixes, and obtains slurries;
(2) additive being sent into grinding pot, add the aluminium dihydrogen phosphate of weight of additive 2%, being ground to fineness is 100 μm;
(3) each raw material after above-mentioned process is mixed, stir, be spray-dried, be pressed into base, sintering, obtain the described niobium based ferrite core material for transformer.
Through detecting, the basic mechanical design feature index that the product of above-described embodiment 1 gained reaches:
The initial permeability of magnetic core of the present invention is more than 2700 μ i;
Maximum magnetic flux core loss (100Kc, 200mT) unit: KW/m3: 396(100±2℃);
Curie temperature is higher than 240 DEG C.