CN105060870B - A kind of preparation method of high-coercive force strontium hexaferrite - Google Patents
A kind of preparation method of high-coercive force strontium hexaferrite Download PDFInfo
- Publication number
- CN105060870B CN105060870B CN201510434381.9A CN201510434381A CN105060870B CN 105060870 B CN105060870 B CN 105060870B CN 201510434381 A CN201510434381 A CN 201510434381A CN 105060870 B CN105060870 B CN 105060870B
- Authority
- CN
- China
- Prior art keywords
- coercive force
- preparation
- srfe
- strontium hexaferrite
- strontium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Magnetic Ceramics (AREA)
- Hard Magnetic Materials (AREA)
Abstract
The invention belongs to technical field of magnetic materials, disclose a kind of preparation method of high-coercive force strontium hexaferrite.Described preparation method comprises the following steps：(1) by Al2O3It is added to a Preburning material SrFe of strontium ferrite12O19Central, it is placed in after batch mixing in planetary ball mill and carry out wet grinding and obtain slurry；(2) slip filter cloth is hung to do to moisture content be between 20%～25%, be subsequently placed in and compressing under wet pressing pressing under magnetic field press obtain blank；(3) blank is placed in agglomerating plant and is warming up to sintering temperature and is sintered for 1190～1290 DEG C, cool down after insulation 30～120min, obtain high-coercive force strontium hexaferrite.The preparation method of the present invention no rare earth adds, with low cost, and has the advantages of technological operation is simple, and addition is easily controllable, preparation time is short, and by the preparation technology optimizing, gained strontium ferrite has good magnetic property.
Description
Technical field
The invention belongs to technical field of magnetic materials is and in particular to a kind of preparation side of high-coercive force strontium hexaferrite
Method.
Background technology
Strontium hexaferrite is the maximum class permanent magnet material of current production rate, because having higher magnetic property, high corrosion resistant
Corrosion, cheap price and the features such as be easy to industrialized mass production, have been widely used for electro-acoustic element, automatization at present
Equipment, speaker, weather monitoring, communication element, micromotor, chemical industry equipment, agricultural breeding, motor vehicles starting motor, meter
The every field such as calculation machine system, electric bicycle, military instrument, marine exploration.But its remanent magnetism, coercivity and magnetic energy product are all relatively
Rare earth permanent-magnetic material is much lower, therefore limits the application of strontium ferrite.The approach improving magnetic properties of strontium ferrite is main
For improving technique preparation process and ion doping.Find that the preparation technology of strontium ferrite becomes very much by substantial amounts of research
Ripe, the method improving magnetic properties of strontium ferrite by improving preparation technology acts on less, and the study hotspot of current industry is main
Concentrate on and ion doping is carried out to it.
Nowadays studying more doped chemical mainly has La, Co, Zn etc., and the wherein research with regard to La, Co is this year
Study hotspot.Eighties of last century late nineteen nineties, the TDK company of Japan combines replacement with La-Co and has prepared high performance FB9
Serial strontium ferrite.Under both is rare earth ion doped, the remanent magnetism of strontium ferrite and coercivity are all improved, Jin Eryin
Fa Liao various countries researchers are to rare earth ion doped research enthusiasm.However, with rare earth shipment amount on international market in recent years
Decline and price rise, people gradually begin to focus on and how to improve iron strontium oxide magnetic using non-rare earth doping
Energy.
The ultimate principle of ion doping is the Fe in strontium ferrite3+Ion is on five kinds of different brilliant positions, is respectively
2a, 2b, 4f1,4f2,12k, wherein 2a, 4f2,12k are in the octahedron that oxonium ion is surrounded, 2b and 4f1 is respectively at oxygen
In hexahedron and tetrahedron that ion surrounds.But the Fe on this five kinds brilliant positions3+The ion not necessarily all overall magnetic to strontium ferrite
Positive effect can be played, this is because due to Fe3+Ion and O2+The result of the superexchange interaction between ion is final to be made to be located at
Ion magnetic moment in these three lattice positions of 2a, 2b, 12k is in arranged in parallel, and the magnetic ion in this lattice position of 4f1,4f2
Square is in but arranged anti-parallel with the ion magnetic moment on above three magnetic time dot matrix.Application No. CN201010524184.3 in 2010
Chinese publication employ the strontium ferrite that a kind of ion substitution method has prepared high-coercive force.This patent uses sweet ammonia
Acid-nitrate process, with strontium nitrate, ferric nitrate and aluminum nitrate as raw material, with glycine as fuel, has prepared the strontium of high-coercive force
Ferrite.But be widely used that ceramic post sintering method due to industrial, so this preparation method exists in commercial Application
Significant limitation.
Content of the invention
In place of solving the shortcoming and defect of above prior art, it is an object of the invention to provide a kind of high-coercive force
The preparation method of strontium hexaferrite.
The object of the invention is achieved through the following technical solutions：
A kind of preparation method of high-coercive force strontium hexaferrite, comprises the following steps：
(1) by Al2O3It is added to a Preburning material SrFe of strontium ferrite12O19Central, it is placed in planetary ball after batch mixing
Carry out wet grinding in grinding machine and obtain slurry；
(2) slip filter cloth is hung do to moisture content be 20%～25% between, be subsequently placed in wet pressing pressing under magnetic field press
Under compressing obtain blank；
(3) blank is placed in agglomerating plant and is warming up to sintering temperature and is sintered for 1190～1290 DEG C, insulation 30～
Cool down after 120min, obtain high-coercive force strontium hexaferrite.
Batch mixing described in step (1) refers to stoichiometrically formula SrFe12-xAlxO19Carry out batch mixing, wherein 0.1≤x≤
0.7, preferably 0.3≤x≤0.5.
Secondary additive CaCO can be simultaneously introduced in described mixing process3、SiO2、H3BO3And dispersant gluconic acid
Calcium, CaCO3、SiO2、H3BO3And the addition of calcium gluconate be respectively 0.8wt%, 0.2wt%, 0.3wt% and
0.6wt%.
The actual conditions of the wet grinding described in step (1) is：Using the hardened steel ball of a diameter of 6mm, by 8:1:1.5
Ball, material, the mixing of water ratio carry out ball milling, and rotational speed of ball-mill is 300r/min, and Ball-milling Time is 4 hours.
The described compressing actual conditions of step (2) is：Forming magnetic field is 8000Oe, and briquetting pressure is 7Mpa, pressurize
Time is 20s, and molding cycle is 200s；Described blank refers to the round billet of a diameter of 20mm.
Intensification described in step (3) refers to：Rise to 150 DEG C with the speed of 2 DEG C/min from room temperature, be incubated 60min；With 3
DEG C/speed of min is warming up to 450 DEG C from 150 DEG C, is incubated 60min；It is warming up to 830 DEG C with the speed of 4 DEG C/min from 450 DEG C, protect
Warm 30min；Sintering temperature is warming up to from 830 DEG C with the speed of 5 DEG C/min.
Described sintering temperature is preferably 1250 DEG C；Described insulation is preferably incubated 90min.
Described cooling is taken out after referring to cool to 200 DEG C with the furnace and is placed in the air natural cooling.
The preparation method of the present invention has the advantage that and beneficial effect：
(1) preparation method of the present invention is ceramic post sintering method, the method have low cost, easy to operate, be easy to real
The feature of existing industrial mass production；
(2) present invention is used Al element as main doped chemical, to strontium ferrite coercitive lifting have very aobvious
The effect writing；
(3) present invention need not add rare earth element, has reduces cost, reduces the effect of rare earth usage amount；
(4) present invention formed by preferred feedstock, compressing condition and sintering process, and by adding the two of specified quantitative
Secondary addition of C aCO3、SiO2、H3BO3And dispersant calcium gluconate, enable aluminium element successfully to dissolve in strontium ferrite lattice
In, give full play to the chanza of aluminium element；
(5) by the amount of mixing of preferred sintering temperature, temperature retention time and Al element, products therefrom has relatively the present invention
While high-coercive force, can preferably control the size of crystal grain, keep good magnetic property.
Brief description
Fig. 1 is sintered obtaining high-coercive force strontium hexaferrite for the embodiment of the present invention 1 at different temperatures
SrFe11.8Al0.2O19And pure SrFe12O19XRD diffraction pattern；
Fig. 2 is sintered obtaining high-coercive force strontium hexaferrite for the embodiment of the present invention 1 at different temperatures
SrFe11.8Al0.2O19Lattice paprmeter a, c with sintering temperature change curve；
Fig. 3 is sintered obtaining high-coercive force strontium hexaferrite for the embodiment of the present invention 1 at different temperatures
SrFe11.8Al0.2O19SEM spectrogram；
Fig. 4 is sintered obtaining high-coercive force strontium hexaferrite for the embodiment of the present invention 1 at different temperatures
SrFe11.8Al0.2O19Hysteresis graph；
Fig. 5 is sintered obtaining high-coercive force strontium hexaferrite for the embodiment of the present invention 1 at different temperatures
SrFe11.8Al0.2O19Remanent magnetism Jr, coercivity HcChange curve with sintering temperature；
Fig. 6 is sintered obtaining high-coercive force strontium hexaferrite for the embodiment of the present invention 1 at different temperatures
SrFe11.8Al0.2O19Magnetic energy product (BH) max with sintering temperature change curve；
Fig. 7 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 2 under the different sintered heat insulating times
SrFe11.8Al0.2O19And pure SrFe12O19XRD diffraction pattern；
Fig. 8 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 2 under the different sintered heat insulating times
SrFe11.8Al0.2O19Lattice paprmeter a, c with temperature retention time change curve；
Fig. 9 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 2 under the different sintered heat insulating times
SrFe11.8Al0.2O19Jr、HcCurve chart；
Figure 10 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 2 under the different sintered heat insulating times
SrFe11.8Al0.2O19SEM spectrogram；
Figure 11 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 3 under the conditions of different Al ions dosage
SrFe12-xAlxO19And pure SrFe12O19XRD diffraction pattern；
Figure 12 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 3 under the conditions of different Al ions dosage
SrFe12-xAlxO19Lattice paprmeter a, c with Al ions dosage change curve；
Figure 13 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 3 under the conditions of different Al ions dosage
SrFe12-xAlxO19The SEM spectrogram of (x is respectively 0.1,02,0.3 and 0.4)；
Figure 14 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 3 under the conditions of different Al ions dosage
SrFe12-xAlxO19Hysteresis graph；
Figure 15 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 3 under the conditions of different Al ions dosage
SrFe12-xAlxO19Jr、HcCurve chart；
Figure 16 obtains high-coercive force strontium hexaferrite for the embodiment of the present invention 3 under the conditions of different Al ions dosage
SrFe12-xAlxO19Magnetic energy product (BH) max change curve.
Specific embodiment
With reference to embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention do not limit
In this.
Embodiment 1
A kind of preparation method of high-coercive force strontium hexaferrite of the present embodiment, concrete preparation process is as follows：
(1) by Al2O3It is added to a Preburning material (SrFe of strontium ferrite12O19) in the middle of, stoichiometrically formula
SrFe11.8Al0.2O19Carry out batch mixing, and add the CaCO of above-mentioned batch mixing gross mass 0.8%3, 0.2% SiO2, 0.3%
H3BO3And 0.6% calcium gluconate, be subsequently placed in planetary ball mill and carry out wet grinding and obtain slurry, the concrete bar of wet grinding
Part is：Using the hardened steel ball of a diameter of 6mm, by 8:1:1.5 ball, material, the mixing of water ratio carry out ball milling, and rotational speed of ball-mill is
300r/min, Ball-milling Time is 4 hours；
(2) slip filter cloth is hung do to moisture content be 20%～25% between, be subsequently placed in wet pressing pressing under magnetic field press
Under the compressing round billet obtaining a diameter of 20mm, compressing actual conditions is：Forming magnetic field is 8000Oe, briquetting pressure
For 7Mpa, the dwell time is 20s, and molding cycle is 200s；
(3) round billet is placed in agglomerating plant, is warming up to 1190 DEG C, 1210 DEG C, 1230 DEG C, 1250 DEG C, 1270 DEG C respectively
It is sintered with 1290 DEG C, cool to 200 DEG C with the furnace after insulation 90min, then take out air cooling, obtain high-coercive force hexagonal strontium ferrum
Oxysome SrFe11.8Al0.2O19, the detailed process of described intensification is：Rise to 150 DEG C with the speed of 2 DEG C/min from room temperature, insulation
60min；It is warming up to 450 DEG C with the speed of 3 DEG C/min from 150 DEG C, be incubated 60min；Heated up from 450 DEG C with the speed of 4 DEG C/min
To 830 DEG C, it is incubated 30min；Sintering temperature is warming up to from 830 DEG C with the speed of 5 DEG C/min.
The present embodiment is sintered obtaining high-coercive force strontium hexaferrite SrFe at different temperatures11.8Al0.2O19And it is pure
SrFe12O19XRD diffraction pattern as shown in Figure 1.The XRD figure data of contrast Fig. 1 can find, under different sintering temperatures
SrFe11.8Al0.2O19XRD diffraction maximum and pure SrFe12O19Diffraction maximum is basically identical, dephasign, each sample principal phase
It is single M phase constitution.However, contrast can find when temperature is less than 1250 DEG C further, with the rising of sintering temperature
Each diffraction maximum gradually moves to high angle direction.From Bragg diffraction equation, this shows the rising ferrite with temperature
Interplanar distance gradually less.In addition, when temperature is higher than 1250 DEG C, can be seen that SrFe from the XRD figure of Fig. 111.8Al0.2O19's
Diffraction maximum is slightly different with respect to other curves.First, each diffraction maximum substantially to low angle offset, and unlike other diffraction maximums to
High angle moves.Secondly, during for 1270 DEG C, lower when its diffraction maximum peak intensity is compared to 1250 DEG C；When temperature reaches 1290 DEG C
When each diffraction maximum peak intensity even more occur in that the reduction of high degree.These phenomenons show when sintering temperature is more than 1250 DEG C,
Sample interior there occurs some changes, leads to its lattice structure also to there occurs change.Speculate that its reason is likely due to high temperature and burns
The hexagonal lattice structure that knot result in sample there occurs destruction, thus causing XRD diffraction maximum peak intensity to reduce.
The present embodiment is sintered obtaining high-coercive force strontium hexaferrite SrFe at different temperatures11.8Al0.2O19Crystalline substance
Lattice constant a, c with sintering temperature change curve as shown in Fig. 2 the lattice paprmeter of Fig. 2 is according to (008), (107) in Fig. 1
This two diffraction maximums calculate according to interplanar distance formula.From figure 2 it can be seen that for SrFe11.8Al0.2O19, its lattice
Constant is gradually reduced with the rising of sintering temperature, and this is gradually reduced with interplanar distance and matches.Al ion substitution Fe3+Ion
The reduction of lattice paprmeter why occurs afterwards, is because Al3+The ratio of ionic radii Fe of ion3+Ion is little, as an Al3+From
Son replaces a Fe3+After ion, lead to space at this that space occurs.Under the influence of interatomic interaction force, periphery is former
Son is to Al3+At ion place, extruding leads to lattice to be distorted.Meanwhile, interplanar distance and lattice paprmeter are gradually reduced and show：When
When sintering temperature raises, Al ion enters SrFe12O19Amount in lattice structure is also bigger；When sintering temperature is not enough, secondary mix
The Al ion of miscellaneous middle addition does not fully enter SrFe12O19In lattice, between they there may be present between crystal grain and crystal grain
In gap, or it is present in SrFe with other forms12O19In.Additionally, can be seen that from the variation tendency of lattice paprmeter
SrFe when 1230 DEG C to 1270 DEG C11.8Al0.2O19Lattice paprmeter a and c change less, illustrate that now major part Al ion is equal
Have enter in lattice.
The present embodiment is sintered obtaining high-coercive force strontium hexaferrite SrFe at different temperatures11.8Al0.2O19's
SEM spectrogram is as shown in Figure 3 ((a)：1190 DEG C, (b)：1210 DEG C, (c)：1230 DEG C, (d)：1250 DEG C, (e)：1270 DEG C, (f)：
1290℃).From figure 3, it can be seen that before 1250 DEG C, the rising strontium ferrite grain size with sintering temperature is more equal
Even, the pore quantity in magnet is gradually reduced, fine and close by original loosely connected gradually change between magnetic-particle.But work as temperature
When being raised to more than 1270 DEG C, occur in that in sample that abnormal crystal grain is grown up, these bulky grains are likely to the magnetic property to sample
Adversely affect.Because if sintered particles are excessive, then magnetic domain granule in rotation process can reduce to coercitive contribution,
In addition the appearance of multidomain grain also can bring detrimental effect to coercivity.This explanation should be strict in strontium ferrite preparation process
Control the sintering temperature of sample, sintering temperature is too low to lead to density not, and sintering temperature is too high to will appear from bulky grain.
The present embodiment is sintered obtaining high-coercive force strontium hexaferrite SrFe at different temperatures11.8Al0.2O19Magnetic
Stagnant curve chart is as shown in Figure 4；Its remanent magnetism Jr, coercivity HcChange curve with sintering temperature is as shown in Figure 5；Its magnetic energy product (BH)
Max is as shown in Figure 6 with the change curve of sintering temperature.From fig. 4, it can be seen that when temperature is not more than 1250 DEG C, the magnetic of sample
Stagnant curve has good squareness, its squareness ratio all close to in 1.However, sample magnetic hysteresis is bent when temperature is more than 1250 DEG C
The squareness of line is substantially deteriorated, and this is likely to and SrFe under high temperature11.8Al0.2O19The abnormal grain! growth that sample interior occurs
Relevant.From Fig. 5,6 it can also be seen that when temperature is not more than 1250 DEG C, the H of samplecTotally assume the trend being gradually reduced,
Its range of decrease is more uniform；The J of sampler(BH)maxThen gradually rise, amount of increase is also more uniform.And work as temperature and be more than 1250 DEG C, sample
HcOccur significantly declining.When temperature is increased to 1290, its coercivity from from 1250 DEG C of 4918.69Oe rapid drawdown to
244.73Oe；Magnetic energy product is also from 1250 DEG C of 28.1kJ/m3Drastically drop to 6.4kJ/m3.
Contrast SrFe11.8Al0.2O19The XRD of sample, SEM data can draw, before 1250 DEG C sample principal phase be single
M phase, when sintering temperature is more than 1250 DEG C, the granule of abnormal growth can adversely affect to magnetic property really.Therefore, for
Its optimal sintering temperature of M-type strontium ferrite of Al ion doping is at 1250 DEG C about.
Embodiment 2
A kind of preparation method of high-coercive force strontium hexaferrite of the present embodiment, concrete preparation process is as follows：
(1) by Al2O3It is added to a Preburning material (SrFe of strontium ferrite12O19) in the middle of, stoichiometrically formula
SrFe11.8Al0.2O19Carry out batch mixing, and add the CaCO of above-mentioned batch mixing gross mass 0.8%3, 0.2% SiO2, 0.3%
H3BO3And 0.6% calcium gluconate, be subsequently placed in planetary ball mill and carry out wet grinding and obtain slurry, the concrete bar of wet grinding
Part is：Using the hardened steel ball of a diameter of 6mm, by 8:1:1.5 ball, material, the mixing of water ratio carry out ball milling, and rotational speed of ball-mill is
300r/min, Ball-milling Time is 4 hours；
(2) slip filter cloth is hung do to moisture content be 20%～25% between, be subsequently placed in wet pressing pressing under magnetic field press
Under the compressing round billet obtaining a diameter of 20mm, compressing actual conditions is：Forming magnetic field is 8000Oe, briquetting pressure
For 7Mpa, the dwell time is 20s, and molding cycle is 200s；
(3) round billet is placed in agglomerating plant, rises to 150 DEG C with the speed of 2 DEG C/min from room temperature, be incubated 60min；With 3
DEG C/speed of min is warming up to 450 DEG C from 150 DEG C, is incubated 60min；It is warming up to 830 DEG C with the speed of 4 DEG C/min from 450 DEG C, protect
Warm 30min；It is warming up to 1250 DEG C with the speed of 5 DEG C/min from 830 DEG C to be sintered, be incubated 30min, 60min, 90min respectively
With cool to 200 DEG C after 120min with the furnace, then take out air cooling, obtain high-coercive force strontium hexaferrite SrFe11.8Al0.2O19.
The present embodiment obtains high-coercive force strontium hexaferrite SrFe under the different sintered heat insulating times11.8Al0.2O19And it is pure
SrFe12O19XRD diffraction pattern as shown in fig. 7, through careful contrast in Fig. 7 the intensity of each diffraction maximum with position it is found that
(006), (008), (0014) parallel to c-axis is respectively the strongest cutting edge of a knife or a sword, secondary strong peak and three strongest peak.Illustrate that sample has preferentially
Orientation, has preferable uniaxial anisotropy.Meanwhile, from this figure it can be seen that prolongation with temperature retention time, non-parallel to
The intensity of diffraction maximums such as (107), (108), (2011) in c-axis direction is also strengthening.The present embodiment is in the different sintered heat insulating times
Under obtain high-coercive force strontium hexaferrite SrFe11.8Al0.2O19Lattice paprmeter a, c with temperature retention time change curve such as
Shown in Fig. 8, as can be seen that the prolongation lattice paprmeter with temperature retention time is in gradually on the whole from the lattice paprmeter change of Fig. 8
The trend reducing.This means that temperature retention time is longer, the quantity that Al ion dissolves in lattice is also more, and chanza becomes apparent from.
The present embodiment obtains high-coercive force strontium hexaferrite SrFe under the different sintered heat insulating times11.8Al0.2O19's
Jr、HcCurve chart is as shown in Figure 9.It can be seen in figure 9 that when temperature retention time is less than 90min, with the prolongation of temperature retention time,
The J of samplerAnd HcAll there is the growth of different amplitudes.Wherein JrRise to 385.75mT, H from 377.70mTcRise to from 4904.28Oe
4918.69Oe.Continue to extend temperature retention time to discovery during 120min, the remanent magnetism of sample and coercivity are all on a declining curve.
The present embodiment obtains high-coercive force strontium hexaferrite SrFe under the different sintered heat insulating times11.8Al0.2O19's
SEM spectrogram is as shown in Figure 10 ((a)：30min, (b)：60min, (c)：90min, (d)：120min), contrast from Figure 10 permissible
Find, when temperature retention time is for 120min, in the crystal grain of sample, occur in that many bulky grains, its maximum particle size is about 30 μ
M, is more than 15 times of stock size (2 μm).The reason this is likely to hydraulic performance decline.Therefore, for SrFe11.8Al0.2O19Sample
Product, its optimal temperature retention time is 90min.Temperature retention time is too short will to lead to the principal phase crystallization time not, sample consistency
Decline, thus reducing the magnetic property of strontium ferrite；Temperature retention time is long will to lead to abnormal crystal grain to be grown up, and particle size is significantly super
Go out optimal single domain size thus bringing adverse effect to sample.
Embodiment 3
A kind of preparation method of high-coercive force strontium hexaferrite of the present embodiment, concrete preparation process is as follows：
(1) by Al2O3It is added to a Preburning material (SrFe of strontium ferrite12O19) in the middle of, adjust Al ions dosage and divide
Not stoichiometrically formula SrFe11.9Al0.1O19、SrFe11.8Al0.2O19、SrFe11.7Al0.3O19、SrFe11.6Al0.4O19、
SrFe11.5Al0.5O19、SrFe11.4Al0.6O19And SrFe11.3Al0.7O19Carry out batch mixing, and add above-mentioned batch mixing gross mass 0.8%
CaCO3, 0.2% SiO2, 0.3% H3BO3And 0.6% calcium gluconate, be subsequently placed in planetary ball mill
Row wet grinding obtains slurry, and the actual conditions of wet grinding is：Using the hardened steel ball of a diameter of 6mm, by 8:1:1.5 ball, material, water ratio
Example mixing carries out ball milling, and rotational speed of ball-mill is 300r/min, and Ball-milling Time is 4 hours；
(2) slip filter cloth is hung do to moisture content be 20%～25% between, be subsequently placed in wet pressing pressing under magnetic field press
Under the compressing round billet obtaining a diameter of 20mm, compressing actual conditions is：Forming magnetic field is 8000Oe, briquetting pressure
For 7Mpa, the dwell time is 20s, and molding cycle is 200s；
(3) round billet is placed in agglomerating plant, rises to 150 DEG C with the speed of 2 DEG C/min from room temperature, be incubated 60min；With 3
DEG C/speed of min is warming up to 450 DEG C from 150 DEG C, is incubated 60min；It is warming up to 830 DEG C with the speed of 4 DEG C/min from 450 DEG C, protect
Warm 30min；It is warming up to 1250 DEG C with the speed of 5 DEG C/min from 830 DEG C to be sintered, after insulation 90min, cool to 200 with the furnace
DEG C, then take out air cooling, respectively obtain high-coercive force strontium hexaferrite SrFe11.9Al0.1O19、SrFe11.8Al0.2O19、
SrFe11.7Al0.3O19、SrFe11.6Al0.4O19、SrFe11.5Al0.5O19、SrFe11.4Al0.6O19And SrFe11.3Al0.7O19.
The present embodiment obtains high-coercive force strontium hexaferrite SrFe under the conditions of different Al ions dosage12-xAlxO19
And pure SrFe12O19XRD diffraction pattern as shown in figure 11, from the XRD figure of Figure 11 as can be seen that when x≤0.3, sample is equal
Miscellaneous peak does not occur, principal phase is single M phase constitution.Illustrate when x≤0.3, the ferritic phase composition to M-type strontium of Al ion substitution
Do not have much affect.The present embodiment obtains high-coercive force strontium hexaferrite SrFe under the conditions of different Al ions dosage12- xAlxO19Lattice paprmeter a, c with Al ions dosage change curve as shown in figure 12, from the lattice paprmeter change of Figure 12
In as can be seen that increase with Al ions dosage, the lattice paprmeter of sample is in the trend being gradually reduced.By analysis before
It is found that the reduction of lattice paprmeter is due to the less Al of ionic radius3+Ion substitution has fallen the larger Fe of ionic radius3+
Ion has caused hexagonal lattice distortion of lattice to occur, thus result in the reduction of lattice paprmeter.This also illustrates to replace with Al ion
The increase of generation amount, has more Fe ions to be substituted.
The present embodiment obtains high-coercive force strontium hexaferrite SrFe under the conditions of different Al ions dosage12-xAlxO19
SEM spectrogram as shown in figure 13 ((a)：X=0.1, (b)：X=0.2, (c)：X=0.3, (d)：X=0.4), permissible from Figure 13
Find out, each sintered particles are evenly distributed, and there is obvious hexagonal structure.As x=0.1, its particle size is about 1 μm；When
It is about 2 μm during x=0.2；When x continues to increase, particle size has the trend continuing to increase.In figure shows with Al ion concentration
The increase of x, the contact surface between sintered particles is more and more unintelligible.Phase is even more presented between each sintered particles under high Al ion concentration
The mutually trend of coalescence.This shows that Al element can affect the ferritic sintering character of M-type strontium, has fluxing action to sample.
Additionally, from figure it is also seen that sample all hole presence of some in the case of each doping, the density of sample is described still
There is the space of lifting.
Add to SrFe to analyze Al element further12O19The impact of chemical composition, using scanning electron microscopic observation group
EDS spectroscopy detection has been carried out to sample during knitting pattern, result is as shown in table 1 simultaneously.
Table 1 SrFe12-xAlxO19Power spectrum (EDS) analysis result of sample
SrFe as can be seen from Table 112-xAlxO19In sample contain four kinds of essential elements, do not comprise other elements or its
The amount of his element is considerably less and is not detected by EDS.Due in SrFe12O19In sample, the atomic percent of each element is respectively
Sr=3.125%, Fe=37.5%, O=59.375%.Carefully the data in contrast table can be seen that tri- kinds of elements of Sr, Fe, O
EDS testing result similar with Theoretical Calculation.Due to having carried out Al element doping, as can be seen from the table the amount of Al element with
The increase of x and gradually increasing, and its atomic percent is with theoretical value closely, and this illustrates that the Al element of secondary interpolation is big
Enter partly into SrFe12O19In lattice and define SrFe12-xAlxO19Compound.
For M-type strontium ferrite, its magnetic is mainly derived from Fe3+The ferrimagnetism itself having and M type hexagonal strontium ferrum
The magnetocrystalline anisotropy energy that oxysome shows along c-axis direction.But Al3+Ion due to being a kind of non magnetic ion, by it
Add SrFe12O19In will certainly cause weakening of neighbouring atomic interaction, thus leading to the reduction of sample magnetic property, such as surplus
Magnetic Jr, Curie temperature TcDeng.The present embodiment obtains high-coercive force strontium hexaferrite under the conditions of different Al ions dosage
SrFe12-xAlxO19Hysteresis graph as shown in figure 14, it can be seen that each SrFe under different Al ions dosage12- xAlxO19Sample all has good squareness, and its squareness ratio is also close to 1.Even if this shows the feelings in different Al ions dosage
Under condition, M-type strontium ferrite all has preferable magnetocrystalline anisotropy.Its Jr、HcWith magnetic energy product (BH) max change curve respectively
As shown in Figure 15 and Figure 16.As can be seen from the figure with the increase of Al ions dosage, SrFe12-xAlxO19The J of samplerWith
(BH)maxIn monotone decreasing.As x=0, Jr=405.25mT；As x=0.7, Jr=318.48mT, reduces about 20.4%.Magnetic
Energy product is from 29.5kJ/m3Drop to 19.1kJ/m3, the range of decrease is about 35.3%.In contrast, the H of samplecThen mix with Al ion
The increase of miscellaneous amount and monotonic increase.As x=0, Hc=4232.41Oe；As x=0.7, Hc=6260.62Oe, increases about
47.9%.It is known that in M-type strontium ferrite, ferric ion Fe3+It is respectively at 2a, 2b, 12k, 4f1 and 4f2 lattice
On position.The ferric ion number occupying former three in one of strontium ferrite structure cell is 16, both positions after occupying
Iron ion number is 8, and the former orientation is contrary with the latter.Total magnetic moment of magnet is mainly contributed by the former, i.e. 2a, 2b, 12k
Fe at position3+Ion.Remanent magnetism J in the present embodimentrWhy can reduce with the increase of Al ions dosage, be because
Research is had to confirm non magnetic ion A l3+Can dissolve in strontium ferrite lattice after sintered, and preferential substitution source is in 2a and 12k position
The magnetic ion Fe putting3+.For coercivity Hc, lattice can be caused due to after the Fe ion substituting on diverse location of Al ion
Distortion, makes the Fe ion near this position original close at this, Distance Shortened each other, and then increases between them
Interaction force.The increase of distortion of lattice and ion Interaction Force so that the magnetic domain within M-type strontium ferrite outside
Plus during the action of a magnetic field, steering and the difficult of movement increase, so that the coercivity H of samplecIncreased.XRD figure from Figure 11
And the B-H loop in figure of Figure 14 can be seen that Al ion doping amount more, SrFe12-xAlxO19The lattice of sample structure cell
Distortion is more serious, and its coercivity is also bigger；But in order to keep the good intensity of magnetization, the scope of amount x of Al ion doping is preferably
0.1≤x≤0.7, preferred scope is 0.3≤x≤0.5.
Above-described embodiment is the present invention preferably embodiment, but embodiments of the present invention are not subject to above-described embodiment
Limit, other any spirit without departing from the present invention and the change made under principle, modification, replacement, combine, simplify,
All should be equivalent substitute mode, be included within protection scope of the present invention.
Claims (6)
1. a kind of preparation method of high-coercive force strontium hexaferrite it is characterised in that：Described preparation method comprises the following steps：
(1) by Al2O3It is added to a Preburning material SrFe of strontium ferrite12O19Central, it is placed in planetary ball mill after batch mixing
In carry out wet grinding and obtain slurry；
(2) slip filter cloth is hung do to moisture content be 20%～25% between, be subsequently placed in wet pressing pressing under magnetic field press and push
The type of making obtains blank；
(3) blank is placed in agglomerating plant and is warming up to sintering temperature and is sintered for 1190～1290 DEG C, insulation 30～
Cool down after 120min, obtain high-coercive force strontium hexaferrite；
Also it is simultaneously introduced secondary additive CaCO during batch mixing described in step (1)3、SiO2、H3BO3And dispersant Fructus Vitis viniferae
Calciofon, described CaCO3Addition be 0.8wt%, SiO2Addition be 0.2wt%, H3BO3Addition be
0.3wt%, the addition of calcium gluconate is 0.6wt%；
Described in step (1), the actual conditions of wet grinding is：Using the hardened steel ball of a diameter of 6mm, by 8:1:1.5 ball, material, water
Ratio mixing carries out ball milling, and rotational speed of ball-mill is 300r/min, and Ball-milling Time is 4 hours；
Intensification described in step (3) refers to：Rise to 150 DEG C with the speed of 2 DEG C/min from room temperature, be incubated 60min；With 3 DEG C/
The speed of min is warming up to 450 DEG C from 150 DEG C, is incubated 60min；It is warming up to 830 DEG C with the speed of 4 DEG C/min from 450 DEG C, insulation
30min；Sintering temperature is warming up to from 830 DEG C with the speed of 5 DEG C/min.
2. a kind of high-coercive force strontium hexaferrite according to claim 1 preparation method it is characterised in that：Step
(1) batch mixing described in refers to stoichiometrically formula SrFe12-xAlxO19Carry out batch mixing, wherein 0.1≤x≤0.7.
3. a kind of high-coercive force strontium hexaferrite according to claim 2 preparation method it is characterised in that：Step
(1) batch mixing described in refers to stoichiometrically formula SrFe12-xAlxO19Carry out batch mixing, wherein 0.3≤x≤0.5.
4. a kind of high-coercive force strontium hexaferrite according to claim 1 preparation method it is characterised in that：Step
(2) described in, compressing actual conditions is：Forming magnetic field is 8000Oe, and briquetting pressure is 7MPa, and the dwell time is 20s,
Molding cycle is 200s；Described blank refers to the round billet of a diameter of 20mm.
5. a kind of high-coercive force strontium hexaferrite according to claim 1 preparation method it is characterised in that：Described
Sintering temperature is 1250 DEG C, and the time of insulation is 90min.
6. a kind of high-coercive force strontium hexaferrite according to claim 1 preparation method it is characterised in that：Described
Cooling is taken out after referring to cool to 200 DEG C with the furnace and is placed in the air natural cooling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510434381.9A CN105060870B (en) | 2015-07-22 | 2015-07-22 | A kind of preparation method of high-coercive force strontium hexaferrite |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510434381.9A CN105060870B (en) | 2015-07-22 | 2015-07-22 | A kind of preparation method of high-coercive force strontium hexaferrite |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105060870A CN105060870A (en) | 2015-11-18 |
| CN105060870B true CN105060870B (en) | 2017-03-08 |
Family
ID=54490451
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510434381.9A Active CN105060870B (en) | 2015-07-22 | 2015-07-22 | A kind of preparation method of high-coercive force strontium hexaferrite |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105060870B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106187144A (en) * | 2016-07-07 | 2016-12-07 | 成都信息工程大学 | A kind of high-performance low-temperature sintered hexagonal crystalline substance M-type strontium ferrite and preparation method thereof |
| CN106567123A (en) * | 2016-11-15 | 2017-04-19 | 彭晓领 | Preparation method of high-coercivity strontium ferrite |
| CN106866131A (en) * | 2017-02-23 | 2017-06-20 | 海安县巨力磁材有限责任公司 | A kind of preparation method of high-performance permanent-magnet ferrite |
| CN107117955B (en) * | 2017-05-03 | 2020-08-18 | 武汉理工大学 | Preparation method of high-purity X-type hexagonal strontium cobalt ferrite material |
| CN109970441A (en) * | 2018-12-24 | 2019-07-05 | 海安南京大学高新技术研究院 | The method that stainless steel etching sludge prepares strontium ferrite |
| CN111439995B (en) * | 2019-01-17 | 2022-04-26 | 四川京都龙泰科技有限公司 | High-performance Co-free hexagonal permanent magnetic ferrite material and preparation method thereof |
| CN112209707B (en) * | 2020-09-24 | 2022-03-25 | 横店集团东磁股份有限公司 | Preparation method of high-performance permanent magnetic ferrite |
| CN114804847B (en) * | 2021-01-21 | 2023-05-23 | 自贡市江阳磁材有限责任公司 | Permanent magnetic ferrite and preparation method thereof |
| CN115385679B (en) * | 2022-08-30 | 2023-08-11 | 西南应用磁学研究所(中国电子科技集团公司第九研究所) | Strontium ferrite material with high remanence ratio, high coercivity and low ferromagnetic resonance linewidth and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103787420A (en) * | 2014-01-25 | 2014-05-14 | 陕西科技大学 | Method for preparing SrFe12O19 magnetic nano powder by using microwave hydrothermal method |
| CN104211388A (en) * | 2014-09-03 | 2014-12-17 | 安徽工业大学 | Preparation method of M-shaped strontium ferrite SrFe12O19 suitable for being sintered at low temperature |
-
2015
- 2015-07-22 CN CN201510434381.9A patent/CN105060870B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103787420A (en) * | 2014-01-25 | 2014-05-14 | 陕西科技大学 | Method for preparing SrFe12O19 magnetic nano powder by using microwave hydrothermal method |
| CN104211388A (en) * | 2014-09-03 | 2014-12-17 | 安徽工业大学 | Preparation method of M-shaped strontium ferrite SrFe12O19 suitable for being sintered at low temperature |
Non-Patent Citations (1)
| Title |
|---|
| 纳米添加剂对锶铁氧体磁性能的影响;李志杰等;《磁性材料及器件》;20130930;第44卷(第5期);第70-72、79页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105060870A (en) | 2015-11-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105060870B (en) | A kind of preparation method of high-coercive force strontium hexaferrite | |
| CN102050619B (en) | Method for preparing permanent magnet oxysome material | |
| Jacob et al. | Effect of Gd3+ doping on the structural and magnetic properties of nanocrystalline Ni–Cd mixed ferrite | |
| CN112679207B (en) | Permanent magnetic ferrite material and preparation method thereof | |
| CN101552069A (en) | Magnetoplumbite permanent magnetic ferrite and method of producing the same | |
| CN104230326B (en) | The preparation method of M type calcium permanent ferrite | |
| CN104230323A (en) | M-type calcium-lanthanum-cobalt permanent magnetic ferrite and preparation method thereof | |
| CN109400139A (en) | A kind of preparation process of low cost permanent-magnet ferrite material | |
| CN101786869B (en) | Calcium permanent magnetic ferrite material and preparation method thereof | |
| CN110467452A (en) | A kind of permanent-magnet material and preparation method thereof | |
| CN107382303A (en) | A kind of preparation method and magnet of high-performance permanent-magnet ferrite magnet | |
| CN110372365A (en) | A kind of preparation method of permanent-magnet ferrite material | |
| CN104230325A (en) | Preparation method of permanent magnetic ferrite pre-sintering material and preparation method of permanent magnetic ferrite | |
| CN115312283B (en) | High-compaction-density injection magnetic powder and preparation method thereof | |
| CN103172360A (en) | Plumbite type yttrium permanent magnetic ferrite material and preparation method thereof | |
| CN109851349A (en) | A kind of high-performance environment protection type hexagonal permanent-magnet ferrite material and preparation method thereof | |
| Eikeland et al. | Enhancement of magnetic properties by spark plasma sintering of hydrothermally synthesised SrFe 12 O 19 | |
| CN105601265A (en) | M-type strontium ferrite magnetic material and method for preparing same | |
| CN104230321B (en) | M type calcium permanent ferrites and preparation method thereof | |
| CN115340373A (en) | Preparation method of hexagonal ferrite material based on low-purity iron concentrate raw material system | |
| CN104230322A (en) | M-type calcium permanent magnetic ferrite and preparation method thereof | |
| CN110204326A (en) | A kind of ferrite permanent-magnet materials and preparation method thereof with core-shell structure | |
| CN109836147A (en) | A kind of permanent-magnet ferrite and preparation method thereof | |
| CN107473724A (en) | A kind of preparation method and product of high-performance M types calcium strontium ferrite | |
| CN106554197A (en) | The method that high-performance permanent-magnet ferrite is prepared by composite algorithm |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |