DE618850C - Production of objects with high and constant permeability, low coercive force and low hysteresis - Google Patents

Description

Bibliofheek
fcssr. Ind. Self-dom

150CT. 1935

ISSUED ON
SEPTEMBER 20, 1935

REICH PATENT OFFICE

PATENT LETTERING

CLASS 40 b GROUP 14

Electrical Research Products, Inc. in New York

Patented in the German Empire on July 27, 1926

The subject of the invention is a process for the production of objects with high and constant permeability, low coercive force and low hysteresis. The invention lies in the following: For the production of the objects are alloys having from 5 to 77% cobalt, 10 to 75 ° / o nickel and 10 to 37 ° used / ₀ pure iron. In order to obtain the transactions mentioned magnetic Eigenxo, the articles are heated at approximately-1100 ⁰ C for at least an hour and then allowed to cool slowly in the oven.

A special heating process consists in that the objects are first ^{brought from 900 to 1100 °} C. over ^{90 minutes, then annealed at 1100 °} for about 70 minutes and then ^{cooled from 1100 to 350 °} C. over 180 minutes.
The objects according to the invention serve, for example, as coils or piece loads and continuous loads of low and carrier frequency signal conductors in submarine and land lines for telephony and telegraphics, furthermore as loading coils for composite telephone and telegraph systems, transmission coils or transformers, in particular as battery supply coils, wave filter coils, for certain classes of relays, dynamo-electric machines, high frequency electromagnetic devices and magnetic circuits of electrical measuring instruments.

The subjects of the invention can be particularly advantageous for continuous Load on telephone lines or long undersea telegraph cables with high Signaling speed can be used. Compared to the use of materials with variable permeability within the range of magnetizing forces, as they have been used so far, great advantages are achieved hereby.

What is known is the fact that certain alloys have a relatively constant permeability over a certain range of magnetic forces and also have a relatively low hysteresis loss. Furthermore, magnetic substances have also become known which consist of nickel and iron and which contain a very small amount of cobalt as an impurity. Finally alloys are already known, the pure iron, 40 to 70 ° / "Nickel and contain up to ro ° / ₀ cobalt. These alloys have proven themselves well with regard to their mechanical, chemical and electrical properties at low temperatures (below freezing point). They have not been used as a magnetic material.

The invention is further illustrated by means of individual examples.

ι. example

A particular magnetic material according to the invention consists of approximately 5 to 45 ° / ₀ nickel, 25% cobalt and 30% iron with about 0.5% manganese, which is added to increase the processing ability. The material has a face-centered cubic-crystalline structure. The curves given in FIGS. 1 to 9 inclusive relate to this example and serve to explain the invention. The object made of this magnetic material is to be treated at a high temperature. The specific heat treatment to be carried out will be described later.

In all the figures of the drawing are the magnetizing forces and flux densities ao. plotted in CGS units.

The magnetization curve in Fig. 1 shows that the material has the high flux density of 15,000 CGS units with a magnetizing force of 45 Gauss. The curve (Fig. 2) shows the great constancy of the permeability up to a magnetizing force of almost two Gauss; thereafter the initial permeability is about 460 for this particular material. Curve α of Fig. 3 represents the upper half of the hysteresis loop for flux densities up to 600 CGS units, which appears as a straight line. No hysteresis loss could be detected by ballistic methods; Coercive force and remanence are therefore practically zero. Using more accurate inductance bridge methods applicable to low inductions, the hysteresis loss was found to be 0.024 X io ~

erg cm ³

per period

found at an induction of 100 CGS units. This value is almost negligible, so that the hysteresis loss could not be shown on the scale of the drawing. The hysteresis loop therefore appears as a straight line. Curves b and c show the corresponding values for Silitstahl and Armco iron.
Fig. 4 to 9 contain half hysteresis loops of the material for different maximum inductions and illustrate the hysteresis losses with increasing induction. The ascending branch indicated by circles and the descending branch indicated by dots in Fig. 4 coincide and form a straight line that goes through the starting point and indicates the absence of hysteresis, remanence and coercive force. A comparison of Fig. 4 with Fig. 2 shows that the initial permeability is constant up to inductions of 600 CGS units.

Figs. 5 to 8 show the hysteresis losses when the flux density increases even further. In Fig. 5 and 6 the hysteresis is already noticeable, but the areas of the Loops are relatively small and the hysteresis loss is therefore insignificant. if but the flux density reaches values of 1500 or more, as shown in Figs the hysteresis loss increases rapidly; nevertheless are noteworthy Remanence and coercive force are still practically zero.

Fig. 9 shows one half of the hysteresis loop for a flux density of approximately "15000 CGS units. This loop takes the general form of the ordinary hysteresis loop, which you get with iron and other magnetic materials. she differs fundamentally from the curves in Figs. 7 and 8 in that the coercive force and remanence are considerable, albeit less than most magnetic ones Materials. This is especially true for the remanence. The hysteresis loss at this high maximum flux density is therefore relatively low in comparison with that of other magnetic materials.

2nd example

The curves of fig. 10 to 14 inclusive relate to a magnetic material according to the invention containing 60 ° / ₀ nickel, 15 ° / ₀ cobalt and 25% iron. The initial permeability in this case is 631 and remains constant up to 700 CGS units. Fig. 10 shows both a magnetization curve and a hysteresis loop for B == 13 250. Fig. 11 is a graphical representation of the permeability for fluctuating values of the magnetizing force. Figs. 12 to 14 inclusive are halves of hysteresis loops for individual induction values. Figs. 13 and 14 also show magnetization curves and hysteresis loops for the material of this example.

3rd example

A material consisting of approximately 70% nickel, 15% cobalt and 15% iron, has an initial permeability of 390 and no significant change in permeability up to induction of CGS units.

4th example

The curves in Fig. 15 to iS including- > borrowed relate to a material made of approximately 73.3% nickel, 6% cobalt and

20.5% iron and 0.2% manganese, which has an initial permeability of 1430 and constancy the permeability up to 715 CGS units Figure 15 is the graph of permeability in Dependence on the field strength. Figures 16 through 18 illustrate halves of hysteresis loops for individual induction values. The maximum permeability is about 5600 with a magnetizing force of i, i Gauss.

5th example

A composition of approximately 20 ° / o nickel, 50% cobalt and 30 ° / ₀ iron shows a negligible change in the permeability at 4 Gauss magnetizing forces of which produces a flux density of 450 CGS units in this case.

6th example

The curves of Figs. 19 to 22 including. lent refer to a material of approximately 50 ° / ₀ nickel, 30 ° / ₀ cobalt and 20% iron, which has an initial permeability of 231, up to the values of B = 716, H = 3.1 is constant.

7th example

Fig. 23 to 28 inclusive relate to a material of 10 ° / ₀ nickel, 70 ° / o cobalt and 20 ° / o iron, less than 1 ° / o manganese, which constant initial and no hysteresis loss has up to a flux density of 225 , the permeability in this area being 57. In addition to half a hysteresis loop for 80 Gauss, Fig. 24 also shows the magnetization curve of the material indicated by dots. In summary, it should be noted that in the magnetic materials according to the invention, hysteresis loss, coercive force and remanence for inductions of 500 to 1000 are negligible. They also have very low coercivity and remanence, often approaching zero, with inductions as high as 5000 CGS units.

To achieve the highest values of the initial permeability combined with constancy the permeability should, as tests have shown, the nickel at least 20% of the include magnetic material content. The highest degree of constancy of permeability, combined with high initial permeability and low hysteresis loss, has been achieved with percentages of iron, which extend up to 37%.

In order to further explain the properties of these materials, the following additional data is given. The composition of 45% nickel, 25 ° / o cobalt and 30 ° / ₀ iron (. Cf. Example 1) has a resistance of 19 micro-ohm / cm; a maximum permeability of 2075 at H = 4.12; Remanence of 3400 and coercive force of 1.3 at H = 50 Gauss. The hysteresis loss is negligible at a maximum flux density of 570 CGS units and amounts to

^{9 '54} Έη ^ ^{pr0 period at}

5> ⁶ 5 erg at

960; 93.2 erg at 1500; 1185 erg at 5050: 2500 erg at 8480 and 3375 erg at 14900. The material, which contains 60 ° / ₀ nickel, 15 ° / ₀ cobalt and 25 ° / ₀ iron (see example 2), has a flux density of 13,250 CGS units at H = 30.7; a resistance of 17.5 micro-ohms / cm; Remanence and coercive force of 1700 and 0.7 for h -f- 30.7 Gauss and. a maximum permeability of 2680 at H = 2.45. The hysteresis loss is negligible up to ß = 895 and amounts to

1.24% per period at a maximum

Flux density of 725 CGS units; 8.4 ergs at S40; 27 erg at 1050; 8S erg at 1250; 632 erg at 5400; 1240 erg at 8230; 150S erg at 13 250.

The material of 73.3% nickel, 6 ° / ₀ cobalt, 20.5 ° / ₀ iron and 0.2 ° / ₀ manganese (see. Example 4) has one. Resistance of 15.5 micro-ohms / cm, remanence and coercive force of 2700 or 3.5 at H = 21 Gauss, maximum permeability of 5600 at 1.1 H and negligible hysteresis loss at flux densities of up to 715 CGS units. The hysteresis loss per cm ³ and period is 23 ergs at a flux density of 1520 CGS units; 348 ergs for 5125 and 785 ergs for 11,500.

The material of 10% nickel, 70% cobaite and 20% iron with a fraction of ι% manganese (see. Example 7) has a resistance of 15.36 micro-ohms / cm; Remanence and coercive force of 9340 and 3.56 at 80 Gauss, maximum permeability of 1545 at H = 6.5 and negligible hysteresis loss at flux densities up to CGS units. The hysteresis loss per cubic centimeter and period is erg at a flux density of 340 CGS units; 150 erg at 620; 1040 erg at 1700; 2740 ergs for 3950, and 14 160 ergs for 500 CGS units.

Any of the above exemplified compositions Small amounts of manganese can either be used as an impurity or as an additive included to make the material more machinable. Chromium or similar elements or substances can be added to increase the specific resistance of the material or for other purposes.

A special property of the material according to the invention is that after application of a strong direct current or a rectified magnetizing force of large values and subsequent reduction to a low value, it has a greatly increased permeability for superimposed weak and alternating magnetizing forces. In a particular case ίο a temporary field strength increased by about 25 Gauss in the alloy of 45 ° / ₀ nickel, 25% cobalt and 30% iron, the initial permeability of 435 to 750th

In other words, the permeability curve follows the curve in Fig. 2 for increasing applied magnetizing fields; at . Decrease in the field, however, by small steps the measured values of the permeability deviate from the curve in Fig. 2. This deviation is not great until the point of maximum permeability is reached. Left but from the point of maximum permeability the value of the permeability is higher Magnetization considerably above the curve and has in the particular mentioned above Trap an initial value of 750. So if a sample of the material is highly magnetized becomes, the characteristic of constant permeability for a range of magnetizing Forces disturbed. To bring the initial permeability back to a lower value, the material must be demagnetized. In order to restore the constancy of the permeability to the highest degree, is it is essential to give the material a new heat treatment.

Another property that is usually evident in these materials is that the magnetization curve for high values of induction often lies partially outside the hysteresis loop. This is e.g. For example, in Fig. 10 the case where the magnetization curve (indicated by dots) crosses the lower branch of the hysteresis loop (indicated by circles) at an induction of B = 500 and merges with it at an induction of 2? = about 7000 reunited. In Fig. 14 the magnetization curve crosses the loop and has a small part lying outside the hysteresis loop. The magnetization curve for inductions greater than that shown in Fig. 14 always has a part outside the hysteresis loop. Another peculiarity is that the hysteresis loss reaches a maximum at a certain value of the flux density, and thus does not increase any further for higher flux densities.

The magnetic properties of the Werko materials according to the invention are under the influence mechanical stresses and tensions are subject to change and must consequently with their use with Handle with care to avoid undue stress and tension.

For the production of the magnetic materials according to the invention, metals can be more commercially available Purity can be melted together in an induction furnace. The molten alloy is in bars or Ingots are cast, which are processed into the desired shapes by rolling, pressing or pulling will.

After the mechanical production of the objects, these are subjected to the thermal process subjected to the generation of the desired magnetic properties. The temperature to which the object heats up and the degree of cooling determine to a large extent the desired magnetic properties.

The object can be annealed in the crucible as usual to prevent oxidation. The annealing takes place at about 100 ° C. for at least one hour, after which the object is allowed to cool in the oven to room temperature. This is the process used in the manufacture of articles from alloys, the magnetic characteristics of which are shown in Figures r through 22. In a special case the object was placed in a chrome-nickel crucible. The crucible was placed in an electric oven as soon as the temperature was at about 900 ⁰ C. In 90 minutes, the temperature of the crucible rose to 1,100 ⁰ C and kept at this temperature for 70 minutes. The object then cooled in the furnace, reaching a temperature of 350 ⁰ C in 180 minutes of cooling time.

The annealed in the crucible article may after-cooling to room temperature again .erhitzt to about 725 ⁰ C. The cooling can be carried out faster than in the first case, with a Ivühlgeschwindigkeit of 2 ° C to 5 ⁰ C per second, down to about 350 ⁰ C down, after which the refrigeration to room temperature with no belie- biger speed.

It can also be used for the annealed object in the crucible after reheating about 725 ° C can be cooled quickly, for example, that this is on a large Copper plate is placed in the open air.

Claims (10)

Patent claims: i. Method of making objects with high and constant Permeability, low coercive force and low hysteresis, which means that draws that alloys with 5 to 77 % cobalt, 10 to 75 ° / ₀ nickel and 10 to 37 ^{% pure iron are used for the production of the objects, and the objects are heated at about 1100 0} C for at least ι hour and then slowly in Let the oven cool down. 2. Embodiment I of the process according to claim, characterized in that accommodated in the heat treatment, the articles initially during 90 minutes from 900 to 1100 ⁰ C, then annealed at 1100 ⁰ about 70 minutes, and then within iso minutes from 1100 to 35 °° C. 3. The use of a material with the composition 5 to 77% cobalt. 10 to 76 ⁰ I ₀ nickel, 10 to 37% pure iron, less than 1% manganese, and ο to i ° / “chromium for the production and heat treatment of objects according to claim 1 or 2. 4. The use of a material with the composition 45% nickel, 25 ° / ,, Cobalt, 30% pure iron for the manufacture and heat treatment of objects according to claim 1 or 2. 5. The use of a material with the composition 73.3% nickel, 6.0% cobalt, 20.5% pure iron, 0.2% 3c manganese for manufacture and heat treatment of objects according to claim ι or 2. 6. The use of a material with the composition 50% nickel, 30% Cobalt, 20% pure iron for the manufacture and heat treatment of objects according to claim 1 or 2. 7. The use of a material with the composition 10 ° / ₀ nickel, 70 ° / ₀ cobalt, 20% pure iron for the production and heat treatment of objects according to claim 1 or 2. 8. The use of a material with the composition 60% nickel, 15% Cobalt, 25% pure iron, used in the manufacture and heat treatment of objects after. Claim 1 or 2. 9. The use of a material of the composition 2o ° / ₀ nickel, 50% cobalt, 30 ° / 'pure iron for the manufacture and heat treatment of objects according to claim 1 or second 10. The use of a material with the composition 70% nickel, 15% Cobalt, 15% pure iron used in the manufacture and heat treatment of objects according to claim 1 or 2. For this purpose 2 sheets of drawings