DD142182A1 - MAGNETIC MATERIAL FOR JOINT RING AND TRANSFER SYSTEMS AND ITS MANUFACTURING PROCESS - Google Patents

Abstract

The invention relates to the above-mentioned magnetic material and its production. The aim of the invention is a material on the basis of a lithium-zinc ferrite with an initial permeability μ-j_ zv / ischen 400 and 800 and a resistivity p> 10 ° Qcm at 100 ° C, which can be produced economically. According to the invention, therefore, at least one of the elements Ti, Bi, Mn, Al, Cr and Ge is added to the lithium-zinc ferrite in total up to 5% by weight of oxides

Description

magnetic material for joining cores and transfer sy-systems and its manufacturing process

Field of application of the invention

The invention relates to a magnetic material for Jochringkerne and transformer systems based on a lithium-zinc ferrite with an initial permeability / U ₁ -. between 400 and 800 and a resistivity P> 10 SL cm in the temperature range between 25 and 100 C ·

Characteristic of the known technical solutions -

It is known to replace manganese-zinc perrites because of the relatively low specific resistance as material for yoke ring cores by nickel-zinc-copper ferrites (DE-03 21 28 051) or magnesium ferrites.

The "magnetic properties satisfy nich-t in each PaIIe ₀ In addition, nickel is relatively expensive.

It is therefore also known, ferrites, composed of. Pe ₂ O ,, CuO ₅ Li ₂ O, ZnO and .ggf "CoO. As material for yoke ring cores

to be used (DE-OS 21 28 051) '.

However, this involves the following disadvantages:

- Complex processing technology to produce homogeneous offsets

- difficult sintering regime

- too low initial permeability

..- relative.-Low resistivity <10 JLcm at 100 ⁰ C.. '

Aim of the invention

The aim of the invention is therefore a Magnetraaterial., Which does not have these disadvantages and which can be produced economically, wherein the 'initial permeability Ai. Values . between 4OO to 800 and the specific resistance Q at 100 ⁰ C> 10 ⁶ JTcm should be.

Explanation of the essence of the invention

The object of the invention is the knowledge of the internal magnetic properties, such as the spontaneous magnetization, the crystal anisotropy constants 1 and 2o order, possible induced anisotropies and the magnetostriction constant ^ ,, ^ ₁ and / ^ ^ qq depending on the concentration of dopings 2-, '3- and 4-valent cations of the temperature and control of the technology for ores rang defined grain structure and fracture defects to infl ^1; solution of the hysteresis loop on Li-Zn-Per-rites anzuw ;;. It is therefore necessary to determine the qualitative dependency of the basic magnetic quantities of special cation additives and to specify a corresponding technology with regard to the hysteresis characteristic. According to the invention, at least one of the following dopants is added:

, Bi ₂ O ₃ , MnO (MnO ₂ , Mn ₃ O ₄ ), Al ₃ O ₃₅ TiO ₂ , GeO ₃ , Co ₂ O ₃ where the sum of the dopants in total can be up to 5 Gev /, - $. It is particularly favorable to add said oxides as doping in the complex _e '.

acts

as a sintering aid. TiO ₀ stabilizes the

T'Gr. '., By its positive contribution to the crystal lysiotropic effect on the formation of Pe ⁺ ions. IJnOp compensates the magnetostriction and thus causes a reduction of the stress energy. ,

AIpO-, and Cr ₂ Oo-act as. In'h-ibitors in crystal growth and improve the homogeneity of the 'grain structure' GeOp is preferred in the. The spinel's tetrahedral lattice is incorporated and makes it possible to influence the coupling between tetrahedral and octahedral magnetization. "In this way, an influence of the curvature transition and the saturation value is possible." It was also found that d i. o combined use of the above five additives leads to a surprising increase in the effects shown.

The properties of the "material according to the invention lie in the following areas:.

Initial permeability / U. = 4OO to 800 at 20 kHz specific resistance! ⁹ - 2.10 cm Curie temperature, T _n = 110 to 250 ^° C. temperature coefficient of initial permeability

: OyU ₁ = 1 to 2 ₀ 10 " ⁶ saturation induction ^B = 3 (-i00 ° C ^> ) ^{= 2000 G}

^B s (20 ° C)> ²⁵⁰ ° ^{G :}

embodiment

By some examples, the invention will be explained in more detail.

Example 1: · . , ·

59.1 mol% Pe ₂ O - ,,; 33.4 mol% ZnO; 5.6 mol% Li ₂ O and 1.9 mol% of MnO are mixed wet four hours in a vibratory mill and then 'the mixture is pre-sintered for two hours at a temperature of 700 ⁰ C.an air, with the addition of 0, 9 wt _o - _0% Bi O-. will be the Vorsintergut in

a'ufgemahlen a vibrator mill wet, with 5 wt.? -% of a 5 '5-VA strength solution granulated, pressed and sintered for three hours at a temperature of 1075 ⁰ C in air.

Igsn.de 'properties were measured:

x , ,

_± = 400 at 20 kHz * f = 5ο10 ^δ .cm.

U ₁ = 80o10 "" ⁶ at 20 kHz T _Q = 222 ⁰ C

Example 2:

Body made from a mixture of 50.6% by mass of PepO ^; 32.1 mol% SnO; S ₅ O mol% TiO ₂ ; 7.4 mol% Li ₃ O and 1.9 Mdl% MnO, processed according to Embodiment 1 exhibit the following properties: / u _± . = 610 at 20 kHz f = 2.10 ⁷ cm

TAAF / η. = 5O ₉ IO " ¹ " ⁶ at 20 kHz T _n =. 112 ⁰ C / 1 c-

Example 3: '' '

Magnetic material according to Example 2, processed according to Example 1, but without BipOo additive had the following properties:. '..'

, U ₁ = 400 at 20 kHz, f = 2.10 cm tan </? / U, = 50oiO ~ ⁶ at 100 kHz 'T ^ = 112 ⁰ C

/ 1 O

- 5 _.

Claims (1)

, J Srf indu'igsans or uch: ' Aging material for yoke cores and having a moderate initial permeability and a high resistivity based on a lithium Ziilk-. Ferrits, characterized in that the material, still. total bis'.zu 5 wt _o -% of oxides containing at least one of the elements Ti, Bi, Mn, Al, 'Cr and Ge. 2 «Method for producing a magnetic material after heat; ], goko η ti ;;, ei cJino i; in that: i.u ball or drum mills in. Dry or Naaser (HpO) treatment or by chemical Mischfällung an intimate mixture of 50 to 60 mol% Pe ₂ O ₃ 30 "35" ZnO . , < 5 "10" Li ₂ O with up to a total of 5 wt _o -% of oxide dopants at least one of the elements Ti ₅ Bi, Mn, Al ₃ Cr and Ge is prepared, thereafter the mixture at a temperature of about 700 ⁰ G in air for about two hours or Op pre-sintered, the pre-sintered material in a ball or drum mill wet to a specific surface of between 5000 to 10,000 cm / g (Blaine) ground, the sus pens ion-spraying miller and the body pressed from the granules two to sfechs hours at temperatures between 950 and 1000 ⁰ C sintered in air or Op Process according to item 2, characterized in that the sintered bodies are rapidly cooled in air to a temperature of 700 ^° C. and then cooled slowly to room temperature,. , , ·