JP2001307602A - Contact material for vacuum valve and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide contact material for a vacuum valve used in a vacuum breaker and the like improving an breaker performance and a manufacturing method of the same. SOLUTION: Contact material is manufactured by pressure-forming mixed powder of Cu powder or the like as a conductive element and Cr powder or the like as an arc resistant element. A surface obtained corresponding to an breaker surface of the contact material and the adjacent part are melted by for example irradiation of laser beam (1 mm or more depth from the surface), and then are rapidly solidified to fine structure of the material. An average particle size of the arc resistant element is maintained as 50 μm or less then the surface is pressed or machined to be smoothed to surface roughness of 10 μm or less and processed in a contact shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to the characteristics required for a contact material of a vacuum valve used in a vacuum circuit breaker and the like.
In particular, the present invention relates to a contact material for a vacuum valve capable of improving the breaking performance and a method for producing the same.

[0002]

2. Description of the Related Art The characteristics required for a contact material for a vacuum valve include three basic requirements represented by the respective properties of a breaking characteristic, a withstand voltage characteristic, and a welding resistance characteristic, and an electric resistance (bulk resistance and contact resistance). It is an important requirement that the temperature rise is low and stable.

However, since these requirements have conflicting characteristics, it is not possible to satisfy all requirements with a single metal material. For this reason, in many contact materials that have been put into practical use, two or more elements that can mutually compensate for the insufficient performance, such as a combination of a conductive component and an arc-resistant component, such as for a large current or a high voltage. Contact materials suitable for specific applications are being developed, and materials having excellent characteristics have been developed and put into practical use. It goes without saying that current can be opened and closed with a high probability from the purpose of use as a switch.

In order to improve the shutoff characteristics of a vacuum valve,
Refinement of the contact structure (particularly, the structure near the pair of contact facing surfaces), reduction of the gas content (particularly, reduction of the gas content near the pair of contact facing surfaces), and unevenness on the contact facing surfaces It is desired that the number is small.

[0005] As a manufacturing process which simultaneously satisfies the miniaturization of the contact structure and the reduction of the gas content, a method in which both a conductive component and an arc-resistant component are melted and then rapidly solidified as in an arc melting method (for example, No. 59-143031) is known.

However, in the case of this arc melting method, since all the contact materials are melted and manufactured, compared with the contacts manufactured by the solid phase sintering method, irregularities (projections) due to fine welding are formed on the contact surface at the time of opening. There is a problem that occurs. The point that should be further improved by the arc melting method is that, in accordance with the current requirements for increasing the breaking current and the flowing current, Te, which is an element for improving the welding characteristics,
When Bi or the like is to be added, since Te, Bi, and the like are high vapor pressure elements, they tend to evaporate, and the addition thereof is difficult.

On the other hand, after a contact material is manufactured by a solid-phase sintering method, one surface of the contact (a cut-off surface which is an opposing surface of a pair of contacts) is melted by an arc, an electron beam, an ion beam, or the like (for example, see Japanese Patent Application Laid-Open No. No. 223075) was developed.

However, in this method, cracks and pores are liable to be formed in the molten portion, which may cause a substance having a degraded performance such as detached particles or a sudden gas between contacts when a large current is interrupted. there were.

In the conventional contact material, the entire contact material or the vicinity of the surface can be made finer with a low gas. However, as the breaking current value increases, the material having a lowering of the breaking performance (disconnected contact constituent material, gas component). Or the probability of occurrence of concavities and convexities on the contact cutoff surface at the time of opening is increased, and the previously expected cutoff performance may not be obtained.

[0010]

As described above, in the conventional contact material, it is difficult to suppress the occurrence of a substance having a degraded interrupting performance and the occurrence of unevenness on the surface serving as the interrupting surface of the contact when the current is interrupted. There was a drawback to decrease.

The present invention suppresses the generation of a substance having a degraded breaking performance and the occurrence of irregularities on the surface of the contact-blocking surface, miniaturizes the vicinity of the surface of the contact-blocking surface and reduces the gas, thereby improving the required breaking characteristics. It is an object of the present invention to obtain a vacuum valve contact material that can be used and to provide a method of manufacturing the vacuum valve contact material.

[0012]

In order to achieve the above object, the invention of claim 1 is to provide a conductive component mainly composed of at least one of Cu and Ag, and Cr, W, Nb, Ta, T
a region containing at least one of i, Mo and these carbides, having an arc-resistant component having an average particle diameter of 50 μm or less and a maximum surface roughness of 10 μm or less, and melting the interruption surface and its vicinity Was 1 mm or more from the surface and did not reach the opposite surface.

[0013] Accordingly, it is possible to suppress the generation of a substance having a deteriorating performance in a contact material of a vacuum valve used in a vacuum circuit breaker or the like and to prevent the occurrence of irregularities on the surface of the contact breaking surface, thereby improving the required performance of the breaking performance. Can be used as a contact material.

According to a second aspect of the present invention, there is provided a contact material comprising a conductive component and an arc-resistant component, the contact material being pressurized to produce a contact material; After the corresponding surface and its vicinity are melted by injection of high energy and then rapidly solidified, a fine-graining step for finely refining the structure of the contact material is performed. This is a contact material for a vacuum valve manufactured by a smoothing process for processing into a contact shape.

Therefore, according to the second aspect of the present invention, it is possible to improve the breaking performance, which is a characteristic required for a contact material of a vacuum valve used in a vacuum circuit breaker or the like.

[0016]

Embodiments of the present invention will be described below. First, the configuration of a vacuum valve to which the contact material of the present invention is applied will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a shut-off chamber. The shut-off chamber 1 includes an insulating container 2 formed of an insulating material in a substantially cylindrical shape, and sealing fittings 3a, 3b at both ends.
And the metallic lids 4a and 4b provided through the intermediary of airtight. A pair of electrodes 7 and 8 which are attached to opposite ends of the conductive rods 5 and 6 and are relatively close to each other are disposed in the shut-off chamber 1. Is a movable electrode. A bellows 9 is attached to the electrode rod 6 of the movable electrode 8 to enable the electrode 8 to move in the axial direction while keeping the inside of the shut-off chamber 1 airtight. A shield 10 is provided to prevent the bellows 9 from being covered with arc vapor. Reference numeral 11 denotes a metallic arc shield provided in the cut-off chamber 1 so as to cover the electrodes 7 and 8, and prevents the inner surface of the insulating container 2 from being covered with the arc vapor. Further, the fixed and movable electrodes 7 and 8 are fixed to the conductive rods 5 and 6 by brazing or crimped by crimping. On opposite surfaces of the movable and fixed electrodes 7, 8, contacts 12a, 12b made of a contact material manufactured according to the present invention are fixed to the electrodes 7, 8 by brazing, respectively.

In order to improve the breaking characteristics of a contact material for a vacuum valve, for example, a Cu-Cr contact, it is necessary to make the structure near the contact surface finer and lower the gas and to make the surface smooth even after current interruption. Some things have been mentioned earlier.

Therefore, in the present invention, a contact material was manufactured by the method described below. That is, as a contact material, a mixed powder of a raw material Cu powder and a raw material Cr powder is subjected to pressure molding (material manufacturing step) to obtain a contact material. At this time, it is desirable that the relative density of the green compact after pressing in the contact material is 90% or more. Degas by heat treatment if necessary. This degassing treatment is performed by heating in a non-oxidizing atmosphere, preferably a hydrogen atmosphere or a vacuum atmosphere.

The surface corresponding to the cutoff surface of the contact material and the vicinity thereof are injected with high energy, for example, by electron beam irradiation, ion beam irradiation, laser irradiation, melting by arc generation, etc., and then by rapid solidification. The structure is refined (miniaturization step). The surface of the contact material corresponding to the current-carrying surface and the area where the vicinity thereof is melted are 1 mm or more from the contact surface and do not reach the opposite surface. One surface of the contact material is made to have an average particle diameter of 50 μm or less of Cr, which is an arc-resistant component of a structure refined by melting and rapid solidification. The atmosphere for making the particles fine by melting and rapid solidification is a non-oxidizing atmosphere, preferably a vacuum atmosphere.

Next, for the purpose of reducing the presence of pores near the contact surface and smoothing the contact surface, a contact material is manufactured by a smoothing step of applying pressure or machining.
Here, the maximum surface roughness after smoothing the surface of the contact material whose structure has been refined is set to 10 μm or less.

In the above-described embodiment, the description has been given of the case where the degassing process is performed after the material manufacturing process. However, the material is sintered when the degassing process is heated. Since the bonding force of the conductive component as the matrix is weak and the degree of freedom is large, it is possible to suppress the occurrence of cracks and pores in the contact material in the subsequent miniaturization step by rapid solidification.

Furthermore, the present invention is not limited to Cu-Cr contacts, but is also applicable to contact materials comprising other conductive components, arc resistant components, and auxiliary components added as necessary. That is, the conductive component of the contact material has at least one of Cu and Ag as a main component, and the arc resistant component of the contact material includes Cr, W, Nb, Ta,
It contains at least one of Ti, Mo, and these carbides. Further, the auxiliary component of the contact material is at least one of Bi, Te, Se, Sb, and Co.
Contains types. Here, the total content of the auxiliary components in the contact material is desirably 5 wt% or less.

The sintering of the contact material manufactured in this manner is likely to progress due to the subsequent assembly process of the vacuum valve, in particular, the brazing process of the contact material and the electrode material made of Cu, which may cause a dimensional change. However, the influence of the dimensional change can be eliminated by adjusting the pressing force in the first material manufacturing process to make the relative density of the green compact 90% or more.

By manufacturing the contact material in the above-described process, the structure near the surface of the contact can be made finer and less gaseous, and the contact can have a smooth surface, which can improve the breaking performance. A contact material can be obtained.

Next, referring to FIG. 2, the contact material for a vacuum valve according to the present invention, a method for manufacturing the same, and the measurement results of the breaking characteristics will be described. (Comparative Examples 1 to 4, Examples 1 and 2) In Comparative Example 1, Cu-50Cr contacts were manufactured by a solid phase sintering method. The Cu powder and the Cr powder are mixed at a weight ratio of 1: 1 and filled in a crucible of φ60 mm, and then 1000 ° C. in a vacuum of the order of 10-3 Pa.
Sintering was performed for 5 hours. The obtained sintered body was molded at 10 t / cm2 in a mold having a diameter of 60 mm, and then sintered again under the same conditions to obtain a Cu-50Cr alloy. After processing this Cu—Cr alloy into a predetermined contact shape (φ50 mm, t5 mm), it was assembled in a vacuum valve and a cutoff test was performed. Block test is 5
The maximum breaking current was measured by gradually increasing the current value from kA. Based on the measurement results of Comparative Example 1, the other measurement results are shown as relative values.

In Comparative Example 2, Cu-50C was used by the arc melting method.
An r-contact was manufactured. Cu-50Cr produced by powder metallurgy
The consumable electrode having the composition of, for example, is injected on the anode side with high-purity Ar, for example, and the consumable electrode is dissolved in a vacuum of the order of 10 ⁴ Pa, and Cu-50 is placed in the opposed water-cooled Cu crucible.
A Cr ingot was obtained. The structure of this Cu—Cr alloy was refined. As a result of performing a cutoff test by incorporating the Cu—Cr alloy into a vacuum valve, the maximum cutoff current was slightly improved.
However, a protrusion was observed on the contact surface after the test, which was a cause of a decrease in the reliability of the breaking performance.

In Comparative Example 3, a Cu-50Cr alloy was obtained by the solid-phase sintering method as in Comparative Example 1, and 10 ⁴
After being irradiated with an electron beam (injection energy is, for example, 1 W / mm ² ) in an Ar atmosphere of the order of Pa, it was rapidly solidified. Although the vicinity of the surface of the Cu-Cr alloy was finer, pores and cracks were observed around the boundary between the molten region and the non-melted region (this is considered to be the effect of partial melting and rapid solidification). ). As a result of performing a cutoff test by incorporating the Cu—Cr contact into a vacuum valve, the performance was almost the same as that of Comparative Example 1.

In Comparative Example 4, Cu-50Cr was used by the sintering infiltration method.
After obtaining the alloy, Ar on the order of 10 ⁴ Pa was applied to one of the bottom surfaces.
After being irradiated with an electron beam in an atmosphere, it was rapidly solidified. Cr
Cr skeleton and infiltrant C produced by compacting the powder under pressure and sintering it in a hydrogen atmosphere at 1150 ° C for 1 hour
u is placed up and down in a crucible and heated at 1150 ° C. in a hydrogen atmosphere to infiltrate Cu, which is a conductive component.
After producing a Cu-Cr alloy containing 50 wt% of Cr and then irradiating with an electron beam (injection energy is, for example, 1 W / mm ² ),
Rapid solidification was performed. Near the surface of this Cu-Cr alloy,
Although it was miniaturized as in Comparative Example 3, pores and cracks were observed around the boundary between the molten region and the non-melted region.
The maximum breaking current of the u-Cr contact was almost equal to Comparative Example 1.

[0029] In contrast Example 1, Cu powder and Cr powder weight ratio of 1: after forming at 10t / cm @ 2 in a mixture mold φ50mm and to be 1, the 10 ⁴ Pa order Ar
After irradiating one of the bottom surfaces with an electron beam (injection energy is, for example, 1 W / mm ² ) in an atmosphere, rapid solidification was performed, and the contact surface was smoothed by machining. This Cu-C
Since the r-contact is not sintered before electron beam irradiation, the bonding of the Cu matrix, which is a conductive component, is weak, and it is possible to flexibly cope with changes in physical properties due to melting, so that pores and cracks are hardly observed. Was. The maximum breaking current of this Cu—Cr contact was slightly improved, and was 1.2 times that of Comparative Example 1.

In the second embodiment, as in the first embodiment, Cu powder and Cr powder are mixed at a weight ratio of 1: 1 to obtain φ5
After molding at 10 t / cm2 with a 0 mm mold, 10 ⁴ P
After irradiating one of the bottom surfaces with an electron beam (injection energy is, for example, 1 W / mm ² ) in an Ar atmosphere of the order of a, rapid solidification was performed. After slightly shaving off the side,
When molded with a 50 mm mold at 10 t / cm 2, no pores or cracks were crushed, and no observation was made.
The maximum breaking current of this Cu—Cr contact was slightly improved, and was 1.2 times that of Comparative Example 1. (Comparative Example 5, Examples 3 and 4) In Comparative Example 5 and Examples 3 and 4, the pressing force in the material manufacturing process was adjusted to produce a Cu-50Cr compact using the relative density as a parameter. After laser irradiation (injection energy is, for example, 2 W / mm ² ) on one of the bottom surfaces in a reduced-pressure Ar atmosphere, rapid solidification was performed, and the contact surface was placed in a mold and smoothed by pressing.

In Comparative Example 5, the relative density of the green compact was 88%
However, at the time of assembling the vacuum valve after the miniaturization step and the smoothing step, the dimensions of the contacts greatly changed after brazing to the electrodes, and it was determined that the contact dimensions were not suitable for the cutoff test, and the cutoff test was not performed.

In Examples 3 and 4, the relative densities of the green compacts were 92% and 96%, respectively. After the miniaturization step and the smoothing step, they were assembled into a vacuum valve and subjected to an interruption test. The current was 1.2 times and 1.3 times that of Comparative Example 1, respectively. (Comparative Examples 6-7, Examples 5-6) In Comparative Examples 6-7 and Examples 5-6, the implantation energy in the step of miniaturizing the contact surface was adjusted, and the depth of miniaturization was set as a parameter.
A u-50Cr alloy was produced. The energy is Cu
-50Cr was injected by generating an arc, rapidly solidified, machined into a predetermined shape (φ50mm, t5mm) by machining, and the surface was smoothed.

In Comparative Example 6, the depth of the fine layer was about 0.6 mm from the surface, and the maximum breaking current was almost equal to Comparative Example 1. As a result of observing the cross section of the contact after the cutoff test, almost no fine layer existing before the test was observed due to the consumption of the contact at the time of current cutoff.

In Example 5 and Example 6, the depth of the fine layer was 2.1 mm and 3.7 mm from the surface, respectively. In each case, it was 1.2 times that of Comparative Example 1.

In Comparative Example 7, a part of the fine layer reached the opposite side of the contact (the depth of the fine layer was 5 m
m) At the time of assembling the vacuum valve, the brazing condition was poor at a rate of about 1/3. Observation of the brazed part of the sample with poor brazing revealed that the brazing material (silver brazing) layer soaked into the contact point, especially at the part where the fine layer reached the opposite side, and the brazing material was thin. It is considered that the strength was weak. (Embodiment 7) In Comparative Examples 1 to 7 and Examples 1 to 6, the example in which only the pressure molding using a mold was performed in the material manufacturing process was described. After the molding, a heating step in a non-oxidizing atmosphere (preferably a hydrogen atmosphere or a vacuum atmosphere) for degassing was performed.

In the seventh embodiment, Cu-30 is formed by pressure molding.
After preparing a compact of Cr, degassing is performed at, for example, 1000 ° C. in a hydrogen atmosphere, and further, smoothing is performed by machining after a finer process by ion beam irradiation (implantation energy is, for example, 0.5 W / mm ² ). After the process, Cu-30
A Cr contact was manufactured. The maximum breaking current of this contact material is
It was 1.2 times that of Comparative Example 1. (Comparative Example 8, Examples 8 to 9) In Comparative Example 8 and Examples 8 to 9, the injection energy and the cooling rate of rapid solidification in the step of miniaturizing the contact surface were adjusted to adjust the size of the Cr particles in the fine layer. A Cu-50Cr alloy having a diameter as a parameter was produced. In addition, energy was injected by irradiating Cu-50Cr with an electron beam, and then the surface was smoothed by pressurization using a φ50 mm mold.

In Comparative Example 8, as a result of using a Cu-50Cr contact having a Cr particle diameter of about 70 μm, the maximum breaking current was almost equal to Comparative Example 1.

In Examples 8 and 9, the Cr particle diameter was 30 μm and 5 μm, respectively, and the maximum breaking current was 1.2 times and 1.3 times that of Comparative Example 1, respectively. (Examples 10 to 11) Comparative Examples 3 to 8 and Examples 1 to 9
Then, the atmosphere in the miniaturization step is 1 in which Ar is implanted.
0 ⁴ has been described examples of the vacuum atmosphere Pa order,
The present invention is not limited to this.

[0039] In Examples 10 and 11, the atmosphere in the fine process, as a high vacuum atmosphere in the vacuum atmosphere and 10- ² Pa order of 3 × 10 ⁴ Pa injected with nitrogen, C
After an arc (for example, 1V, 3000A) is generated at the u-25Cr contact point, it is rapidly solidified and machined to a predetermined shape.
(φ50 mm, t5 mm) and the surface was smoothed. As a result of evaluating the breaking characteristics of these two types of contacts, the maximum breaking current was 1.2 times that of Comparative Example 1 in both Example 10 and Example 11. (Comparative Example 9, Examples 12 to 13) Comparative Example 9 and Example 12
In Nos. To 13, the machining conditions (type of machining tool, machining speed, and the like) in the smoothing process, which is a post-process of the material production process and the miniaturization process, are adjusted, and the surface roughness of the smooth surface is used as a parameter. A -10Cr contact was made.

In Comparative Example 9, the maximum roughness was 15 μm, and the maximum breaking current was almost equal to Comparative Example 1.

In Examples 12 and 13, the maximum roughness was 8 μm and 3 μm, respectively, and the maximum breaking current was 1.2 times and 1.3 times that of Comparative Example 1, respectively.

(Embodiment 14) In the fourteenth embodiment, φ50 m
Using a mold of m, the Cr powder is placed on the oxygen-free copper block, and then pressurized to adopt a material manufacturing process in which the compact of Cr is bonded on the Cu block by pressing force. did. By irradiating the Cr surface with an electron beam and melting and rapidly solidifying, the finely divided Cu
A graded Cu-Cr alloy having a -50Cr layer was obtained.
The Cu—Cr alloy was subjected to a smoothing step by machining to produce a Cu—Cr contact material, and the breaking performance was evaluated. As a result, the maximum breaking current was 1.2 times that of Comparative Example 1.

In the fourteenth embodiment, a combination of a powder of Cu, which is a block of a conductive component, and a powder of Cr, which is an arc-resistant component, has been described. However, the present invention is not limited to this. For example, a combination of a conductive component block, an arc-resistant component and a conductive component mixed powder, a conductive component block and an arc-resistant component wire rod, and a combination of a conductive component powder and an arc-resistant component powder can also be used. (Examples 15 to 20) In Comparative Examples 1 to 8 and Examples 1 to 14, the arc resistant component was Cr.
Although the case of the contact material in which the conductive component is Cu has been described, the present invention is not limited to this.

In Example 15, a Cu-20 wt% W contact in which the arc resistant component was W and the conductive component was Cu was manufactured by making the contact material surface fine and smooth, and as a result of evaluating the breaking characteristics, the maximum breaking was determined. The current was 1.2 times that of the Cu-W contact material when manufactured by a normal solid-phase sintering method that did not go through a miniaturization step or the like.

In Examples 16 to 18, the arc-resistant components were Nb, WC, Cr + W, and the conductive component was Cu.
The contact material was manufactured under the same conditions as in Example 15 and the breaking characteristics were evaluated. As a result, the maximum breaking current was as shown in Examples 16 to 18.
In all cases, the contact material was 1.2 times as large as that of the contact material manufactured by the ordinary solid-phase sintering method without passing through the miniaturization step and the like.

In Examples 19 and 20, contact materials were manufactured under the same conditions as in Example 15 to evaluate the breaking characteristics, with the conductive components being Ag and Ag + Cu, respectively, and the arc resistant component being WC. The maximum breaking current in both Examples 19 and 20 was 1.3 times that of the contact material when manufactured by the ordinary solid-phase sintering method without passing through the miniaturization step and the like. (Examples 21 to 23) Comparative Examples 1 to 8 and Examples 1 to 2
In the case of 0, an example of a contact material composed of a conductive component and an arc-resistant component was described, but this is an embodiment in which an auxiliary component is added to this.

In Examples 21 to 23, Bi, Te, and Te + Se were used as auxiliary components, respectively, and a contact material was manufactured under the same conditions as in Example 15 and the breaking characteristics were evaluated. In all of Examples 21 to 23, the contact material was 1.2 times as large as that of the contact material when manufactured by the ordinary solid-phase sintering method which did not go through the miniaturization step and the like.

As shown by the above results, the contact material for a vacuum valve obtained by the manufacturing method of the present invention can improve the cutoff characteristics.

The arc resistance component is described using Cr, W, Nb, WC, Cr + W in the embodiment of the invention, but Cr, W, Nb, Ta, Ti, Mo, and these are used. At least one of the carbides may be used as a secondary arc resistant component.

The conductive component is also Cu or Ag.
If is used as a main component, a combination with another material can be adopted.

Further, as for the auxiliary component, in the embodiment of the present invention, Bi, Te, Te + Se are described.
At least one of i, Te, Se, Sb, and Co may be used as an auxiliary component.

[0052]

As described above, according to the present invention, it is possible to provide a contact material for a vacuum valve capable of improving the cutoff characteristics and a method for producing the same.

[Brief description of the drawings]

FIG. 1 is a sectional view of a vacuum valve to which a contact material according to the present invention is applied.

FIG. 2 is an explanatory view of a comparative example and an example for explaining the effect of the present invention.

[Explanation of symbols]

1: shut-off chamber, 2: insulating container, 3a, 3a: sealing fitting, 4a, 5b: lid, 5, 6: conductive rod, 7: fixed electrode, 8: movable electrode, 9: bellows, 10: arc shield , 11: Arc shield, 12a, 12
b: contact

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Kusano 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Works Co., Ltd. Terms (reference) 5G026 BA01 BB02 BB04 BB12 BB14 BB15 BB16 BB17 BB18 BC03 BC05 BC07 5G050 AA01 AA12 AA13 AA25 AA27 AA46 AA48 AA51 BA01 BA10 CA04 DA03 EA02 EA11

Claims (10)

[Claims] 1. A conductive component mainly composed of at least one of Cu and Ag, and Cr, W, Nb, Ta, Ti, Mo.
And at least one of these carbides, having an average particle diameter of 50 μm or less and a maximum surface roughness of 10
A contact material for a vacuum valve, having an arc-resistant component of not more than μm, wherein an area for melting a blocking surface and its vicinity is 1 mm or more from the surface so as not to reach the opposite surface. A contact material comprising a conductive component and an arc-resistant component; a material manufacturing step of manufacturing a contact material by pressing the contact material; and a surface corresponding to an interrupting surface of the contact material and its vicinity. Is melted by injecting high energy and then rapidly solidified to form a finer step of refining the structure of the contact material, and a smoothing step of smoothing the finer surface of the structure of the contact material and processing it into a predetermined contact shape. A method for producing a contact material for a vacuum valve, wherein the contact material for a vacuum valve is produced by the process of forming the contact material. 3. The method for producing a contact material for a vacuum valve according to claim 2, wherein the contact material comprises a conductive component, an arc-resistant component and an auxiliary component. 4. The method for producing a contact material for a vacuum valve according to claim 2, wherein the relative density of the green compact after pressurization of the contact material is 90% or more. 5. An area for melting a surface corresponding to a cutoff surface of a contact material and its vicinity is 1 mm or more from the contact surface,
The method for producing a contact material for a vacuum valve according to claim 2, wherein the contact material does not reach the opposite surface. 6. The method for producing a contact material for a vacuum valve according to claim 2, wherein an average particle diameter of the arc resistant component of the microstructure is 50 μm or less. 7. The method for producing a contact material for a vacuum valve according to claim 2, wherein the maximum roughness of the surface after smoothing the finely divided surface is 10 μm or less. 8. The arc resistant component of the contact material is Cr, W, Nb,
The method for producing a contact material for a vacuum valve according to any one of claims 2 to 7, further comprising at least one of Ta, Ti, Mo and a carbide thereof. 9. An auxiliary component of the contact material is Bi, Te, S
The method for producing a contact material for a vacuum valve according to any one of claims 2 to 8, further comprising at least one of e, Sb, and Co. 10. The method for producing a contact material for a vacuum valve according to claim 2, wherein the total content of the auxiliary components in the contact material is 5 wt% or less.