SU1585073A1 - Method of producing composite magnetic circuits - Google Patents

Abstract

The invention relates to the technology of manufacturing composite magnetic cores by powder metallurgy methods and can be used in the manufacture of parts of magnetic systems in the radio engineering and electrical industries. The aim of the invention is to improve the magnetic properties, the quality of the magnetic cores and the efficiency of the process. The molded part obtained by extrusion is sintered in a protective atmosphere, after sintering it is plastic or mechanically processed, pressed into powder, and the collecting magnetic core is sintered at a temperature 50–150 ° C below the sintering temperature of the male part. Get composite magnetic circuits of iron powders with enhanced magnetic properties and accuracy. The yield is 98-99%. 4 tab.

Description

The invention relates to the technology of manufacturing composite magnetic conductors by powder metallurgy methods and can be used in the manufacture of parts for magnetic systems in the radio and electrical industries.

The aim of the invention is to improve the magnetic properties, the quality of the magnetic cores and the efficiency of the process.

The essence of the invention lies in the fact that according to the method of manufacturing composite magnetic cores, including pressing the male part, pressing it with powder to the female part and sintering the preform in a protective atmosphere, before assembling the male part

sintering in a protective atmosphere, after sintering, plastic or mechanical processing is carried out, and the composite product is sintering at a temperature of 50-150 ° C below the sintering temperature of the male part.

For example, in the case of the manufacture of a male part from iron powder, it is sintered at 1100-1200 ° C; in the production of the male part from iron-phosphor material, it is sintered at 1200-1250 ° C (liquid phase sintering).

At these temperatures, the sintering process takes place most completely, the sintered products acquire mechanical properties commensurate with the properties

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about

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you compact materials, and an appropriate structure.

However, their geometrical dimensions do not meet the requirements for details of magnetic systems, the accuracy of which corresponds to grade 2 accuracy or 6-7 grade. The reason for this is uneven shrinkage during sintering.

Plastic or mechanical refining is carried out to give details of the appropriate dimensions. In the manufacture of parts made from iron powder, this may be, for example, compression, with the additional goal of increasing density, or calibration.

In the case of the manufacture of male parts made of iron-phosphorus, due to the high density after liquid-phase sintering (7.4-7.5 g / cm), pressing is not required and the parts are processed to size by calibration or mechanical refinement (centerless grinding).

The pressing of the female part and the assembly is carried out by compaction of the powder relative to the male part. In this case, the destruction of the covered parts does not occur, as they have sufficient strength after sintering.

The prefabricated product is sintered at a temperature of 50-150 ° C below the sintering temperature of the parts covered. At the same time, due to the fact that the sintering processes in the covered parts were sufficiently completed, the repeated shrinkage at lower sintering temperatures is almost zero and amounts to 0.01-0.04%, which does not affect the accuracy of the products.

Re-sintering (annealing) of the male parts in the composite product removes the work hardening and hardening of the surface layer and improves the structure, which favorably affects the magnetic properties.

The shrinkage of the female part during sintering is, depending on the material and density, 0.5-2.0% in diameter, thus the strength of the joint of the male and female parts during the sintering of the assembly

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The magnetic properties of the products correspond to the properties of the solid design of the magnetic circuit, since there is no gap between the male and female components.

The choice of the temperature difference between sintering of the male part and the assembly (LT 50-150 ° C) is conditioned by the requirements for obtaining an optimal combination of magnetic and physicomechanical characteristics.

Example 1. The assembly of a magnetic component (composite magnetic circuit) of a 10GD dynamic head system was carried out. The part to be covered (core) was pressed from a mixture of iron powder of the PLR VZ brand with 0.8-1.2% of phosphorus at a pressure of 7–8 t / cm2. The density of the core after pressing was 6.9-7.0 g / cm3.

Pressings were sintered in dissociated ammonia according to the mode: - 2 hours; 1250 ° С - 4 h, cooling with a furnace to 50.0 СР. Density after sintering 7.4 - 7.5 g / cm3.

After sintering the cores were processed on the centerless grinding wall

in size 0 25 (0,007)

mm Then

0.020

The core was placed in a matrix, a PZhRVZ brand of iron powder was filled around it, and the latter was compacted at a pressure of 8–10 t / cm2. The density of the female part (flange 0 80 mm) after pressing was 7.15 - 7.25 g / cm3. The prefabricated product was sintered in an environment of dissociated ammonia according to the following conditions: cages at 800 ° С; heating to hold 2 hours; cooling with a stove up to 800 C. Density of the flange after sintering 7.2-7.3 g / cm3.

After sintering, the core had a size of 0 25 - (fl flo) mm which corresponds to

requirements of design documentation (CD). Maximum deviations due to core non-perpendicularity with respect to the flange within 0.1 mm, which also meets the requirements of the design documentation.

Measurements of magnetic induction in the working gap of systems manufactured by

Does it increase, because the process is specica-proposed and known methods,

neither under pressure of the female part to be covered by different shrinkage, and diffusion processes are intensified. After caking

are given in table. one.

The magnetization of the systems was carried out at a magnetic field strength of 0.8 T.

are given in table. one.

The systems were magnetized at a magnetic field strength of 0.8 T.

Induction measurements were made using a differential coil and a miliber-fiber meter.

PRI mme R 2. Conducted the manufacture of a composite part of the magnetic system of the dynamic head type 15 DG (composite magnetic core).

The part to be covered (the core) was pressed from annealed iron powder ПЖ4СЗ- at a pressure of 7-8 t / cm2. The density of compacts 6.7-6.9. Pressings were sintered in an environment of dissociated ammonia according to the following conditions: cages at 800 ° С; heating to 1150 ° C; shutter speed 2 h; cooling with oven to 800 ° C. Density after sintering 6.8-7.0 g / cm3 After sintering, the cores were pressed at a pressure of 8-10 t / cm2 to a density of 7.3-7.5 g / cm3. Core sizes 0

,,, 0.020

5 - n "" h mm then the core was placed

In the matrix, an iron powder of the PLRVZ brand was filled around it, and the latter was compacted at the pressure of 8–10 t / cm2. The density of the female part (flange D80 mm) was 7.15-7.25 g / cm3. The prefabricated product was sintered in dissociated ammonia at 1100 ° C. The density of the flange after sintering is 7.2-7.3 g / cm3. After sintering, the core size was 0 25, 0.020. H), 04G

mm, which meets the requirements of the design documentation.

Measurements of magnetic induction are given in table. 2

Example 3. Conducted the manufacture of modular parts of the magnetic system of a horn loudspeaker type 10GR (composite magnetic core).

The part covered (core) was pressed from annealed iron powder ПЖ4СЗ at a pressure of 7-8 g / cm2. The density of compacts 6.8-6.9 g / cm3.

Pressings were sintered in dissociated ammonia in containers according to the mode: charge at 800 ° С} heating to 1200 ° С; shutter speed 2 h; cooling with

furnace up to 800 C. Density after SPECA-50 pressing covered detail spec-

Nor 6.9-7.0 g / cm3. After sintering, the cores were pressed at a pressure of 8-10 t / cm2 to a density of 7.3-7.5 g / cm3.

Core sizes 050- () mm-. Then the core was placed in a matrix, produced

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around it was filled up with an iron powder of the PYARVZ brand, and the latter was compacted at a pressure of 8-10 t / cm2.

The density of the male part (flange 0 124 mm) was 7.0-7.2 g / cm3. The prefabricated product was sintered in dissociated ammonia medium for two hours. The flange density after sintering is 7.1-7.3 g / cm3. After sintering the core was measured

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five

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five

mm that corresponds

0 50 - (° ° 8) p V0.12 requirements of the design documentation. Dimensional tolerances in the tolerance.

Measurements of magnetic induction are given in table. 3

As follows from the table. 1-3, the magnetic conductors manufactured by the proposed method are characterized by higher magnetic properties as compared with similar magnetic conductors obtained in a known manner.

In tab. 4 compares the quality indicators (dimensional accuracy) and the yield for the preparation of composite magnetic cores using the proposed and known methods.

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It follows from Table 4 that the proposed method allows to improve the quality of the magnetic cores by increasing the accuracy of their dimensions, as well as to increase the efficiency of the process by increasing the yield of the useful one from 60-80% for the known method to 98-99%.

Claims (1)

Invention Formula  A method of manufacturing composite magnetic cores, comprising pressing the male part, pressing it with powder of the female part and special composite billet in a protective atmosphere, characterized in that, in order to improve the magnetic properties, the quality of the magnetic cores and the efficiency of the process, the cabin is in a protective atmosphere, the sintered billet is subjected to plastic or mechanical processing, and the sintering of the composite billet is carried out at a temperature 50-150 ° C below the sintering temperature of the male part. Table 1 .- .. allowance for-4 Density, g / cm3 Induction) Note student tv raskoflantsa core than the gap, G the famous 7.6-7.65 7.5-18200 Geometric 7.55 dimensions and maximum deviations do not meet the requirements YU ruled 7.2-7, e 7.4-13500 - 75 T a b l and 2 The method according to-4 Density, g / cm5 Induction Note Radiofravlaf core than the gap,. Gs Known 7.6–7.65 7.5–10600 Geometry7, 55th dimensions and maximum deviations do not meet the requirements of “ni CT” Proposed 7.2–7.3 7.3– 11400 - I: 5 Yes- / one Table3 Method Density, g / cm Induction Note --In OYa.bo- making  than for " core flange I zore, Gs Famous 7.6 7.6 14250 Geometric dimensions and maximum deviations do not meet the requirements of the design documentation Proposed 7.1-7.3 7.3- 14750 7.5