Economic sintering permanent-magnet ferrite and preparing method thereof

A permanent magnet ferrite, sintering temperature technology, applied in the field of sintered permanent magnet ferrite and its preparation, sintered permanent magnet ferrite, can solve the problems of declining market competitiveness, high price, and increased cost of sintered ferrite raw materials, etc. Achieving the effects of low cost, reduced addition amount, and good intrinsic coercive force

CN101209920BActive Publication Date: 2011-01-12HENGDIAN GRP DMEGC MAGNETICS CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2011-01-12

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Abstract

The invention relates to an economic sintered permanent magnetism ferrite and a preparation method thereof. The sintered permanent magnetism ferrite comprises a hexagonal ferrite main phase containing A, R, Fe and Al and has the following molecular formula with characteristics of A1-xRx(Fe12-yAly)zO19 : wherein, A represents one element or more elements of Sr, Ba and Ca, but Sr must be contained;R represents one element or more elements selected from thulium elements and Bi; x, y and z represent mol ratio, namely, 0.01 to 0.1 of x, 0.05 to 0.3 of y and 0.8 to 1.2 of z. The economic sintered permanent magnetism ferrite of the invention adopts Al2O3 with relatively less cost to replace expensive Co oxide, and the compatibility of all elements is rational, thus substantially reducing the addition amount of thulium and having lower cost and higher magnetic capacity. The economic sintered permanent magnetism ferrite preparation method of the invention is simple and has low cost; and the produced sintered permanent magnetism ferrite is provided with higher magnetic induction intensity and better intrinsic coercivity.
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Description

technical field

[0001] The invention relates to a sintered permanent magnet ferrite, in particular to a sintered permanent magnet ferrite and a preparation method thereof, belonging to the technical field of magnetic materials. Background technique

[0002] Sintered permanent magnet ferrite has stable magnetic properties and strong demagnetization resistance; it is not easy to rust and does not need to be coated with a protective layer; it is hard and brittle and can be used for special tool processing and cutting; and it is cheap and low in use. Therefore, it is widely used in automobiles, household appliances, industrial automation and other industries. The oxide permanent magnet ferrite material is mainly strontium ferrite (SrO·6Fe) with magnetoplumbite hexagonal structure. 2 o 3 ) and barium ferrite (BaO·6Fe 2 o 3 ) as a raw material to manufacture sintered permanent magnet ferrite. There are two main parameters that affect the magnetic properties of sintered perman...

Examples

Embodiment 1

[0031] The batching process selects raw materials as follows:

[0032] Fe 2 o 3 powder (of which Fe 2 o 3 The purity of the powder ≥ 99.1wt%, the original average particle size of the particles: 1.0um) 85.3wt%;

[0033] SrCO 3 Powder (purity ≥ 98.0wt%, original average particle size of particles: 2.0um) 12.2wt%;

[0034] La 2 o 3 Powder (purity ≥ 99.0wt%, original average particle size of particles: 0.8um) 1.4wt%;

[0035] Al 2 o 3 Powder (purity ≥ 99.0wt%, original average particle size of particles: 1.2um) 1.1wt%;

[0036] The above-mentioned raw materials were weighed and mixed in a wet ball mill, then dried, and pre-fired in the air. The main phase formula of can be expressed as: Sr 0.9 La 0.1 Fe 11.72 Al 0.25 o 19 .

[0037] The organic dispersant calcium gluconate of 0.4wt% is added to the calcined material of gained; Then calcined material is carried out coarse pulverization and added additive carry out the dry formula coarse pulverization of 5 minutes ...

Embodiment 2

[0045] Raw material selection is the same as implementation example 1, just with La 2 o 3 Change to Bi 2 o 3 , the addition amount of each raw material is as follows: Fe 2 o 3 Powder, 85.95wt%; SrCO 3 Powder, 13.16 wt%; Bi 2 o 3 Powder, 0.42wt%; Al 2 o 3 Powder, 0.47 wt%.

[0046] After pre-firing in the same process, the pre-fired temperature is 1240°C, and the holding time is 1 hour. The components of the obtained pre-fired material can be expressed as Sr 0.98 Bi 0.02 Fe 11.89 Al 0.12 o 19 .

[0047] The organic dispersant sorbitol of 0.8wt% is added to the calcined material of gained; Subsequently, the calcined material is carried out coarse pulverization and the dry formula coarse pulverization of adding additive in 5 minutes in the continuous type dry vibration ball mill, after pulverizing The average particle size of the powder was 4.5 μm.

[0048] Next, weigh 450 grams of the coarsely pulverized material produced in the above-mentioned manner, add 0.5wt%...

Embodiment 3

[0054] Raw material selection is the same as implementation example 2, and each raw material addition is as follows: Fe 2 o 3 Powder, 86.16 wt%; SrCO 3 Powder, 12.95wt%; Bi 2 o 3 Powder, 0.64wt%; Al 2 o 3 Powder, 0.25 wt%.

[0055] After pre-firing in the same process, the pre-fired temperature is 1240°C, and the holding time is 1 hour. The components of the obtained pre-fired material can be expressed as Sr 0.97 Bi 0.03 Fe 11.89 Al 0.06 o 19 .

[0056] The calcium gluconate of 0.4wt% and the polyvinyl alcohol of 0.4wt% are added to the calcined material of gained, subsequently in the continuous type dry vibration ball mill, the calcined material is carried out coarse pulverization and the added additive is carried out the dry type coarse grinding of 3 minutes. Pulverize, the average particle size of the pulverized powder is 5.8 μm.

[0057] Next, weigh 450 grams of the coarsely pulverized material produced in the above-mentioned manner, add 0.5wt% SiO 2 , 0.75wt%...