JPS6014721A - Electrode material of vacuum interrupter and method of producing same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode material for a vacuum interrupter and a method for manufacturing the same.

In general, the electrodes of a vacuum interrupter have the following characteristics: 1) have a high ability to carry and interrupt large currents, 2) have high insulation strength, 3) have good welding resistance, and 4) can interrupt small currents well ( It is required that the electrode conditions such as small cutting current value be satisfied.

Conventionally, various electrode materials have been proposed to satisfy all of the above electrode conditions. However, at present, none of the electrode materials fully satisfies the above-mentioned electrode conditions. No. 41-12131 (see U.S. Patent Classification No. 3.246.979), the electrode is made of copper containing 0.5 molar pinumuth (hereinafter referred to as Cu-0,5Bi electrode). λ, Ma7'rJ, Japanese Patent Publication No. 48-36071 (U.S. Pat.
96.027) are known.

Although electrodes containing these high vapor pressure materials have excellent large current interrupting ability, brush welding properties, and conductivity, they have the disadvantage that the insulation strength, especially at the large current interrupting portion, is significantly reduced. Moreover, since the cutting current value is as high as IOA, the cutting surge may be killed when the current is cut off, so there is a drawback that it is not possible to cut off the delayed small current well, and therefore the electrical equipment on the load side There was a risk of causing dielectric breakdown.

tit, for example, as an electrode intended to overcome the above-mentioned drawbacks of electrodes containing the above-mentioned high vapor pressure materials.
Those made of an alloy of copper and a low vapor pressure material (high melting point material), such as 20-i, which is disclosed in Japanese Patent Publication No. 36121/1983 (see U.S. Pat. No. 3,811,939). % of copper and 80% by weight of tungsten, or the one disclosed in Japanese Patent Application Laid-open No. 1572843/1984 (see British Patent Application Publication No. 2.024.257) is known. There is.

Although electrodes containing these low vapor pressure materials have the advantage of increased insulation strength in view of the electrode conditions described above, it is difficult to interrupt large currents such as short-circuit currents. There were drawbacks.

The present invention has been made in view of the above-mentioned technical level, and
The purpose of this is to greatly increase the insulation strength while maintaining good welding resistance to the extent that it does not cause any disadvantages, and to provide a nitrous nitride that can handle and interrupt both large currents and small tit currents. An object of the present invention is to provide an interrupter electrode material and a manufacturing method thereof.

In order to achieve the above object, the present invention is directed to a vacuum interrupter electric material (material number ←a) and a manufacturing method.

The specific invention is an electrode material made of gold 5 to 40 times I#, - iron and 5
It is composed of a composite metal of ~40 pieces of chromium, 1~1oM size of molybdenum or tungsten, and the rest copper.

Other inventions related to electrode materials include iron powder of 5 to 40 weight and 5 to 401! -fft% chromium powder, and 1
~10% by weight of molybdenum or tungsten powder is infiltrated into a porous substrate that is diffusion-bonded with the remaining weight of tungsten powder. : Constructed from composite metals.

The invention of - relating to the method for producing a superfine powder according to the above-mentioned specified invention is, first, in a non-oxidizing atmosphere, heating a mixed powder of iron, chromium, and molybdenum or tungsten at a temperature lower than the melting point of iron. , a porous base material is formed by diffusion bonding these metals to each other, and then a steel material is placed on the base material in a non-oxidizing atmosphere, and the porous negative base I↓ and the steel material are A method of forming a composite metal by infiltrating a porous base material with steel material by heating at a temperature lower than the melting point and higher than the melting point of copper.
Another invention related to the method for manufacturing an electrode material according to the above-mentioned specific invention is to first place a mixed powder of iron, chromium, molybdenum or tungsten together in a non-oxidizing atmosphere, and then A porous base material is formed by heating at a temperature lower than the melting point of copper to mutually diffuse bond the metals of the mixed powder, and then heated at a temperature higher than the melting point of copper and lower than the melting point of iron to form a porous base material. This is a method of infiltrating steel material into base I by heating the base material and copper@ to form a crude alloy Mk.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings and the drawings.

FIG. 1 is a longitudinal sectional view of an fc pure nitrogen interrupter equipped with electrodes according to the present invention. The ink club A includes a plurality of (two in this example) insulating cylinders t, i' made of cylindrically molded glass or a stretched material such as insulating ceramics.
t, Fe-Ni-Co fixed to both ends of each insulating cylinder 1
Thin annular sealing fittings 2, 2 made of metal such as alloy.・
... by coaxially joining one of them to form an integral insulating cylinder, and both openings of this integral insulating cylinder are connected through the other metal fittings 2, 2 made of stainless steel or the like. The inside of the container, which is closed by disc-shaped end plates 6, 6 and consists of an integral insulating cylinder and metal end plates 6, 6, is evacuated to a high wall to form J4-empty container 4. , this vacuum container 4
The inner trap is a pair of electrode rods in which a pair of disk-shaped electrodes 5.5 are introduced from the center of each whole-island end plate 6 so as to be able to approach and separate from each other while maintaining the airtightness of the Makabe container 4. Through 6,6,
It is generally configured so that it can be brought into contact with and separated from it (contact and separation).

In FIG. 1, C is a bellows, and 8 is an intermediate potential shield concentrically surrounding each electrode 5.

Each electric '@! , 5 is 5-40 weight of iron and 5-4゜l
f: l1ii: Consists of a composite metal material consisting of % of chromium, 1 to 10% of chromium, 1 to 10% of chromium, 1 to 10% of buden or tungsten, and the rest of plane.

This electrode material contains -1oo mesh iron powder 5 to 40 heavy fi! , -% and -100 mesh chromium powder 5-4
0 weight i% and -100 mesh molybdenum or tungsten powder 1 to 10 ni% are mutually granulated,
In addition, a porous base material is formed by diffusion bonding, and the base material has a metal decay structure in which the remaining weight -M% of copper is infiltrated.

Hereinafter, a method for manufacturing the above-mentioned electrode material will be explained.

First manufacturing method First, iron is 5 to 40% by weight, chromium is 5 to 40% by weight,
Molybdenum or tungsten is adjusted to have a composition ratio of 1 to 10% by weight, and the grain size is f10.
A predetermined amount of iron powder, chromium powder, and molybdenum or tungsten powder (e.g., equivalent to one 7c electrode, taking into account the cutting allowance for post-processing) with a mesh size of 0 is mechanically mixed.

Next, the obtained metal mixed powder is mixed with iron and chromium.

It is stored in a container with a circular cross section made of a material that does not react with either molybdenum, tungsten, or copper, such as alumina, and the stored contents are stored in a non-oxidizing atmosphere (for example, in a vacuum at a pressure of 5 x 10' Tarr or less). Heating and holding (in hydrogen gas, nitrogen gas, argon gas, etc.) at a temperature lower than the melting point of iron (1,535℃)
For example, the iron powder, chromium powder, and molybdenum or tungsten powder are diffused and bonded to each other by combing at 600 to 1,000° C. for about 5 to 60 minutes to produce a porous substrate T-film.

Next, in the same or different non-oxidizing atmosphere as in the above diffusion bonding step, a steel material such as a copper block or copper powder is placed on the porous base material, and the porous base material and the copper material are bonded to each other at the melting point of copper. (1,083℃) or above, and the melting point of iron (1,083℃)
535° C.) for about 5 to 20 minutes to infiltrate the molten copper material into the porous base material. This allows iron and chromium.

Manufacture a composite metal material consisting of molybdenum or tungsten and copper.

The first manufacturing method described above is characterized by the fact that the step of forming a porous base material (diffusion bonding) and the step of infiltrating the steel material into this porous base material are completely separated. No copper material is placed in this container when the porous base material is formed by diffusion bonding inside the container.

Therefore, in the first manufacturing method, the formation of a porous base material is carried out in a gas such as full hydrogen gas, nitrogen gas, or argon gas, and the infiltration of the copper material into this porous base material is carried out under true nitrogen drawing. It is also possible.

In addition, a porous columnar base material that can be made into many electrodes in various non-oxidizing atmospheres is manufactured, and this porous columnar base material is cut into the required thickness and shape to form, for example, one electrode. After processing into a porous base material for use, infiltration of the copper material into the porous base material may be carried out by drawing down $e.

Second manufacturing method In the second manufacturing method, a mixed powder of iron powder, chromium powder, molybdenum powder or tungsten powder, and copper material are placed in the same container, and a diffusion bonding process of the mixed powder and copper material is carried out. The feature is that the material infiltration process is performed consistently by changing the heating temperature in the same non-oxidizing atmosphere.

In the second manufacturing method, first, iron is
Iron powder and chromium powder adjusted to have a composition ratio of 40% by weight, 5 to 40% by weight of chromium, 1 to 1oILf/IC- of molybdenum or tungsten, and a particle size of 1100 mesh. and a predetermined amount of molybdenum or tungsten powder.

Then, iron and chromium were added to the obtained whole island mixed powder.

It is housed in a container with a circular cross section made of a material that does not react with either molybdenum, tungsten, or copper, such as alumina, and a steel material is placed on the metal mixed powder.

Next, the contents in the container are placed in a non-oxidizing atmosphere (for example, 5
First, heat and hold at a temperature lower than the melting point of copper (for example, 600
~1,000℃ for about 5 to 60 minutes), and as a result,
Iron powder, chromium powder, and molybdenum or tungsten powder are diffusion bonded to each other to produce a porous base tube.

Next, the melting points (1,
083℃) and lower than the melting point of iron (1,535℃) (e.g. 1,100℃) for about 5 to 20 minutes to infiltrate the molten steel into the porous base material. This results in the production of a composite gold material consisting of iron, chromium, molybdenum or tungsten, and copper.

In addition, 1. In either case of the second method, a vacuum is preferable as a non-oxidizing atmosphere since it has the advantage that degassing can be carried out simultaneously during heating and holding. Of course, there is no problem in practical use as an electrode for a vacuum interrupter even when the electrode is manufactured in a gas other than the back air. fc The diameter t- of each metal particle in each of the above metal powders
The reason for setting the mesh to -100 is to ensure that each metal particle is uniformly dispersed in the metal structure of the electrode material and that mutual diffusion bonding is good.

In addition, the heating temperature and time required for interdiffusion bonding of metal powders depend on the furnace conditions, the shape and size of the porous substrate to be formed,
It is heated and maintained in such a way that it satisfies the desired properties as an electrode material, taking into account the conditions such as the above, and the processing properties, etc., for example, at 600°C for 60 minutes, or at 1,000°C for 5 minutes.
The work is carried out under heating conditions such as minutes.

Next, the total bending structure t-second factor according to the example of the electrode material manufactured by the above-mentioned second manufacturing method (the non-oxidizing atmosphere was in a vacuum of 5 X 10' Torr),
■), (C), (Ll and lJQ and Figure 3 (4)
), Monkey).

Shown in (C), 0)) and (f).

Figure 2 Prisoner, 3rd grade. (03, (p3 and (6) are the electrode materials according to Example-1, and the iron is 23 times
This is a characteristic photograph taken by an X-ray microanalyzer of an electrode material having a composition ratio of 22% by weight of H, chromium, 5% by weight of molybdenum, and 50% by weight of iron.

FIG. 2(g) is a characteristic photograph showing a secondary electron image, and FIG. Figure 2 (Q is a characteristic X-ray image of dispersed chromium Cr, and the scattered white parts are chromium. Figure 2 V) is a characteristic X@ image of dispersed molybdenum MO, and the scattered white parts are is molybdenum. Maf
Figure 2 (g) is a characteristic X-ray image of infiltrated @Cu.
The white part is copper.

As can be seen from this Figure 2, iron (Fe) and chromium (Cr).

Each molybdenum MO powder (powder) is mutually diffusion-bonded to form a porous base material.

Then, by infiltrating the pores (gap) of this porous base material with copper Cu, the composite gold titanium becomes a strong bond as a whole.
- It can be seen that it is forming.

In addition, in ω) to ■ in Figure 2, the white parts indicate the respective elements, and the white parts (parts with many white dots) indicate that the concentration of that element is high. The same applies to Figure 3.) Figure 3 Prisoner, (g),
(C), CD) and (G) are electrode materials according to Example-2, with iron at 23% by weight, chromium at 22% by weight, tungsten at 5% by weight, and copper at 50% by weight.
This is a characteristic photograph taken using an X-ray microanalyzer of an electrode material with a composition ratio of .

Figure 3 is a characteristic photograph showing a secondary electron image, and Figure 3 (C) and U are dispersed white images similar to those in Figure 2), (Q and (G)). The portions represent iron (Fe), chromium (Cr), and copper (Cu), respectively.

FIG. 3(D) is a characteristic X-ray image of dispersed tungsten W. As can be seen from FIG. 3, the scattered white parts are tungsten, Fe, and chromium Cr.

The tungsten W powders are mutually diffusion-bonded to form a porous gold base material. It can be seen that by infiltrating the pores (gap) of this porous base material with copper Cu, a composite metal of a strong bond is formed as a whole.

Example-1 having the whole island structure illustrated and detailed as above
and the electrode material of Example-2, with a diameter of 50 mm and a thickness of 6.5 mm.
The electrode was formed into a circular plate with an R=4 dragon rounded edge around it, and this electrode was assembled into a pair of Sensei's vacuum interrupters shown in Figure 1, and the various performances of this vacuum interrupter were evaluated. I examined it carefully.

The verification results were as follows.

Note that the electrode made of the electrode material containing tungsten shown in FIG. 3 of Example 2-2 is different from that of Example-1 shown in FIG.
1 consisting of an electrode material containing molybdenum! If the performance differs from the standard, it will be noted.

1)? The electrical conductivity (IAC8) of the 11-pole material was 3 to 20% in the case of Example-1, and 2 to 30% in the case of Example-2.

Between these electrodes 5.5'l, a current of 3 kArms is applied.
After applying current for seconds (IEC short-time current standard), both electrodes 5
After that, the increase in contact resistance was limited to 2 to 8 inches.

gf In addition, both electrodes 5,5 and 5,000 times were pressurized with a force of 5,000 times, and a current of 50 kArms was applied between these electrodes 5,5 for 3 seconds. The contact resistance could be removed without any problem with a static tripping force of 10 cm, and the increase in contact resistance after that was limited to 2 to 7 cm.

Subsequently, the welding resistance was maintained well to the extent that it did not cause any inconvenience in terms of use.

3) Cutting current value When the test current was 30 At, the cutting current value was on average 3. s h (standard deviation σ.=1.8
, number of samples n = 100).

In addition, in the case of the %L electrode material containing tungsten in Example-2, the average cutting current value was 3.8A (σ□=i, a, n
=1oo) 1) Tsuta.

4) Large current breaking ability It was possible to completely cut off the current of 12 kArms.

5) Insulation strength Maintaining the gap between electrodes at a total of 3.0, an impulse withstand voltage test was performed, and the result was ±120kV (variation ±10kV).
kV).

6) The insulation strength of the interrupted part was 12 kA, and the gap between the electrodes was maintained at 3.0 mm, and the impulse withstand voltage test was carried out several times. The withstand voltage value is shown.

7) Insulation strength after small current switching A small current continuous switching test was conducted 10,000 times at a current of 80 A. The withstand voltage value varied rapidly from the initial stage to the io and ooo cycles.

8) Leading small current interrupting ability 1.25 Voltage 84 x -77-kV - Current 80 AO Leading small current interrupting test (JEC181) 110,000 times - achieved. No restriking occurred between both electrodes 5.5.

Next, in the electrode material having the composition according to the present invention, iron.

The severing current value (average value when 30A current is applied) and the impulse withstand voltage value when changing the composition ratios of chromium, molybdenum, and aluminum or the composition ratios of iron, chromium, tungsten, and copper are calculated as follows: Shown in the front and second layer.

(Left below) Composition ratios of Fe, Cr, MO and Cu and Table 1 Current cut-off value and impulse withstand strength (Note - Composition ratios are M
Table 2 Breaking current value and impulse stiffness pressure (Note: Composition ratio is weight %, gap between electrodes is 3.0%) Composition ratio of Fe, Cr, W and Cu .O
yxm) As can be seen from the above-mentioned items 1) to 8), a vacuum interac having an electrode made of the electrode material of the present invention,
It has excellent performance, and when compared with the performance of a vacuum interrupter having a Cu-0,5Bi electrode having the same shape as the electrode according to the present invention, the results were as follows.

a) Large current breaking force Between the two.

b) The insulation strength of the pair of Cu-0,5Bi electrodes is 10WI.
The impulse withstand voltage value shown at I+ and the impulse withstand voltage value shown by the pair of electrodes according to the present invention at an electrode gap of 3.0- were the same. Therefore, the electrode according to the present invention has a dielectric strength three times more than that of the Cu-0,5Bl electrode.

C) Welding resistance The welding resistance of the electrode according to the present invention is 70% of the welding resistance of the Cu-0,5Bi electrode. However, in practice, there is almost no problem, and if necessary, the tripping force at the instant of electrode separation can be increased.

d) Ability to advance and interrupt small currents The electrode according to the invention is capable of interrupting loads with twice the capacitance compared to Cu-0,5B1 electrodes.

e) Cutting current value The cutting current value of the electrode according to the present invention is Cu-o, sn
The cutting current value was reduced to 30% of the t-electrode cutting current value.

In addition, electrodes with compositions other than those shown in Tables 1 and 2 have almost the same performance as the compositions of Example-1 and Example-2 in comparison with the Cu-0,5Bi electrode. showed that.

However, when the iron content was less than 5 times i--, the breaking current value suddenly increased, and on the other hand, when it exceeded 40% by weight, the large current breaking ability suddenly decreased.

Furthermore, when the amount of chromium was less than 5% by weight, the breaking current value suddenly increased, while when it exceeded 40% by weight, the large current breaking ability decreased rapidly.

Furthermore, when the amount of molybdenum or tungsten was less than 1% by weight, the insulation strength sharply decreased, and on the other hand, when it exceeded 10% by weight, the large current interrupting ability decreased rapidly.

Furthermore, if the copper content is less than 10% by weight, the contact resistance after energization increases rapidly, as seen from the short-time current test results, and in other words, the conductivity of the electrode decreases rapidly.
Joule heat increases rapidly when the rated current is applied, and copper 1
The practicality of electrodes below 0 wt.

On the other hand, when the copper content exceeded 89%, the dielectric strength and welding resistance rapidly decreased.

As mentioned above, the specified invention consists of 5 to 40 weight iron and 5 to 40 weight iron.
This electrode is a vacuum interrupter electrode made of a composite metal of 40% by weight of chromium, 1 to 10% by weight of molybdenum or tungsten, and the remaining copper, so this electrode is similar to a Cu-0,5Bi electrode. Compared to conventional electrodes containing a high vapor pressure material, the insulation strength of the Makabe interrupter can be dramatically increased, and the cutting current value 1c can be dramatically reduced. Also, the conventional 20Cu-
Compared to an electrode containing a low vapor pressure material such as 80W, large current can be cut off better. Therefore, the electrode material according to the specific invention can effectively perform large current interruption, leading small current interruption, and delayed small current interruption.

Also, 5 to 40 weight iron powder related to the electrode material, and 5 to 40 weight iron powder.
This is an electrode material for a vacuum interrupter, which is made by infiltrating a porous base material in which ~40 weight of chromium powder and 1 to 10 weight of molybdenum or tungsten powder are mutually diffusion-bonded and infiltrated with the remaining weight of steel material. Therefore, in addition to the various effects mentioned above, it is possible to improve the mechanical strength of the electrode.

Also, regarding the method for manufacturing the electrode material according to the specified invention -
In the invention, a mixed powder of iron, chromium, and molybdenum or tungsten is held in a non-oxidizing atmosphere at a predetermined temperature for a predetermined period of time, so that they are mutually diffused and bonded to form a porous base material. Since the electrode material gold is manufactured by placing a steel material and infiltrating the porous base material in a non-oxidizing atmosphere, the bonding between each metal is good and the dispersion state is uniform. In addition, another invention related to a method for manufacturing an electrode material according to the specified invention is a mixture of iron, chromium, and molybdenum or tungsten. The powder and steel material are placed together in a predetermined container, and then, mutual diffusion bonding of the mixed powder and infiltration t-m of the copper material are carried out in the same non-oxidizing atmosphere. Therefore, in addition to the effect associated with the invention mentioned above, there is an effect that a part of the pear making process can be omitted.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a vacuum interrupter having electrodes made of the electrode material according to the present invention;
C), G)) and (g) are iron 23 weight cake, chromium 2
An X-ray microanalyzer image of the characteristics of an electrode material made of a composite material having a composition of 2% by weight, 5% by weight of molybdenum, and 50% by weight of copper. Figure 2 shows the secondary electron image of the electrode material. FIG. 2(B), (0,0) and proviso) show characteristic X-ray images of iron, chromium, molybdenum and infiltrated steel in a dispersed state. Figure 3 (At, (B)
, (C), Q) O, m and (G) are iron 23% by weight,
22% chromium, 5% tungsten and 50% copper
Fig. 3 (4) shows a secondary electron image of the electrode material; (C), (DJ and (to) are iron in a dispersed state;
chromium. Characteristic X@ images of tungsten and infiltrated steel are shown. ;: to 'i' :? ,b',',ζ1(\゛・ζB,
Q;

Claims (4)

[Claims] (1) An electrode material for a vacuum interrupter made of a composite metal of 5 to 40 wt% iron, 5 to 40 wt% chromium, 1 to 10 wt% molybdenum or tungsten, and the remainder silk. (2) 5 to 40 weight iron powder and 5 to 403! An electrode material for an X-empty interconnect made of a composite metal made of a porous base material in which a quantity of chromium powder and a molybdenum or tungsten powder of 1 to 1 oxrt% are mutually diffused and infiltrated with a remaining quantity of silk. (3) First, in a non-oxidizing atmosphere, a mixed powder of iron, chromium, and molybdenum or tungsten is heated at a temperature lower than the melting point of iron to diffuse and bond the metals in the barber powder to each other. Then, in a non-oxidizing atmosphere, a steel material is placed on the porous base material, and the porous base material and the arm stock are heated at a temperature lower than the melting point of iron, and fc, heating at a temperature higher than the melting point of copper to infiltrate the copper material into the porous base material to form a composite metal;
A method for manufacturing electrode materials for vacuum interrupters. (4) First, a mixed powder of iron, chromium, molybdenum or tungsten and a steel material are placed together in a non-oxidizing atmosphere, and then heated at a temperature lower than the melting point of copper to make each of the above mixed powders A porous base material is formed by diffusion bonding metals to each other, and then the copper material is made porous by heating the porous base material and the copper material at a temperature higher than the melting point of copper and lower than the melting point of iron. A method for producing an electrode material for a vacuum interrupter using composite gold by infiltrating it into a solid base material.