JP7062504B2 - Manufacturing method of contact material for vacuum valve and contact material for vacuum valve - Google Patents

Description

An embodiment of the present invention relates to a contact material for a vacuum valve and a method for manufacturing a contact material for a vacuum valve.

The contact material for a vacuum valve (hereinafter, also simply referred to as a contact material) is mainly composed of a conductive component, an arc resistant component, and the like. Then, the type of each component constituting the contact material is appropriately selected according to the use of the contact material.

For example, in a Cu—Cr-based contact material, Cu has conductivity and Cr has arc resistance. In the Cu—Cr-based contact material, in order to further improve the arc resistance, a substance having a melting point higher than the melting point of Cr, particularly fine particles of the substance may be added.

Japanese Unexamined Patent Publication No. 2006-032036

However, the above-mentioned high melting point substance has a weak binding force with Cu, which is a matrix of contact materials. Therefore, when the contacts of the vacuum valve are opened and closed, the substance may be separated from the contact material due to a mechanical impact, an arc impact, or the like. Further, even if the substance does not separate from the contact material, there is a high possibility that cracks or chips will occur on the surface of the contact material, which will be the starting point of breakage of the contact material. When the substance is detached from the contact material or cracks occur in the contact material, the withstand voltage characteristics and breaking characteristics of the contact material deteriorate.

Further, in the contact material, it is required to uniformly form an arc resistant component in the conductive component to improve the withstand voltage characteristic of the contact material.

The problem to be solved by the present invention is that even if a substance having excellent withstand voltage characteristics and improving arc resistance is contained, the substance is detached or cracks on the surface are generated due to an impact at the time of current interruption. It is an object of the present invention to provide a contact material for a vacuum valve and a method for manufacturing a contact material for a vacuum valve that can be suppressed.

The contact material for a vacuum valve of the embodiment is formed in the conductive matrix, a particle-like first arc-resistant component made of chromium formed in the conductive matrix, and the conductive matrix. It is composed of a particle-shaped second arc-resistant component surrounded by the first arc-resistant component and a particle-shaped additive component formed in the conductive matrix and surrounded by the first arc-resistant component. ..

It is sectional drawing which shows typically the contact material for the vacuum valve of embodiment. It is sectional drawing which shows schematically the vacuum valve provided with the contact material for a vacuum valve of an embodiment. It is an enlarged sectional view schematically showing the contact structure of the vacuum valve provided with the contact material for a vacuum valve of an embodiment. 6 is an SEM image of a cross section of a contact material for a vacuum valve manufactured in Example 1. It is an image which mapped the Cu element in the cross section of the contact material for a vacuum valve manufactured in Example 1. It is an image which mapped Cr element in the cross section of the contact material for a vacuum valve manufactured in Example 1. It is an image which mapped the Mo element in the cross section of the contact material for a vacuum valve manufactured in Example 1.

Hereinafter, embodiments will be described with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing a contact material 1 for a vacuum valve according to an embodiment.

As shown in FIG. 1, the contact material 1 for a vacuum valve of the embodiment (hereinafter, also simply referred to as contact material 1) has a conductive matrix 2 and a first arc-resistant component 3 formed in the conductive matrix 2. , A second arc-resistant component 4, and an additive component 5. The contact material 1 is a Cu—Cr-based vacuum valve contact material containing copper (Cu) having conductivity and chromium (Cr) having arc resistance.

The conductive matrix 2 which is the matrix of the contact material 1 is a conductive component of the contact material 1. The conductive matrix 2 is made of Cu.

The contact material 1 contains Cu constituting the conductive matrix 2 in terms of mass ratio, for example, 5% by mass or more and 90% by mass or less, and further 25% by mass or more and 70% by mass or less with respect to the entire contact material 1. When the mass ratio of Cu contained in the contact material 1 is 5% by mass or more, the conductive characteristics of the contact material 1 are improved. Further, when the mass ratio of Cu is 90% by mass or less, the withstand voltage characteristic and the cutoff characteristic of the contact material 1 are improved.

The first arc-resistant component 3 formed in the conductive matrix 2 is composed of a plurality of particulate structures and is uniformly dispersed inside the conductive matrix 2. Further, the first arc-resistant component 3 is a component that is not formed in the vicinity of the second arc-resistant component 4 and the vicinity of the added component 5 (hereinafter, also referred to as the first arc-resistant component 3a) and the second arc-resistant component. It is composed of a component formed in the vicinity of 4 (hereinafter, also referred to as a first arc resistant component 3b) and a component formed in the vicinity of the additive component 5 (hereinafter, also referred to as a first arc resistant component 3c).

Here, the first arc-resistant component formed in the vicinity of each component is a component that surrounds the periphery of each component. In other words, the first arc-resistant component 3b surrounds the second arc-resistant component 4. The first arc-resistant component 3c surrounds the additive component 5. Further, the first arc-resistant component 3a does not surround the periphery of the second arc-resistant component 4 and the periphery of the additive component 5, and is uniformly and alone dispersed in the conductive matrix 2.

Microscopically, the first arc-resistant component 3b gathers around the second arc-resistant component 4, and the first arc-resistant component 3c gathers around the additive component 5, but the contact material 1 as a whole. All the components including the first arc-resistant components 3a, 3b, and 3c, that is, the first arc-resistant component 3, are uniformly dispersed in the conductive matrix 2.

The first arc-resistant component 3 is made of Cr. The contact material 1 contains Cr constituting the first arc resistant component 3 in terms of mass ratio, for example, 5% by mass or more and 50% by mass or less, and further 10% by mass or more and 40% by mass or less with respect to the entire contact material 1. do. When the mass ratio of Cr contained in the contact material 1 is 5% by mass or more, the arc resistance of the contact material 1 increases. Further, when the mass ratio of Cr is 50% by mass or less, the phase separation between the conductive matrix 2 made of Cu and the first arc-resistant component 3 made of Cr is suppressed, and the first arc-resistant component 3 becomes. It is more evenly dispersed in the conductive matrix 2. Therefore, the withstand voltage characteristic and the cutoff characteristic of the contact material 1 are improved.
In the following, unless otherwise specified, the average particle size of each component was determined in the same manner as the average particle size of the structure constituting the first arc-resistant component 3.

The second arc-resistant component 4 formed in the conductive matrix 2 is composed of a plurality of particulate structures and is uniformly dispersed inside the conductive matrix 2. The second arc-resistant component 4 is three-dimensionally surrounded by a plurality of structures constituting the first arc-resistant component 3b.

By surrounding the second arc resistance component 4 with the first arc resistance component 3b, the second arc resistance component 4 from the contact material 1 is caused by the mechanical impact of the contact material 1, the impact of the arc, and the like. Detachment and the occurrence of cracks and chips on the surface of the contact material 1 are suppressed. Therefore, the withstand voltage characteristic and the cutoff characteristic of the contact material 1 are improved.

The second arc-resistant component 4 has a melting point higher than the melting point of Cr constituting the first arc-resistant component 3. For example, the second arc resistant component 4 is composed of at least one element selected from the group consisting of niobium (Nb) and vanadium (V). Further, the second arc resistance component 4 may be composed of one kind of the above-mentioned elements, or may be composed of two or more kinds of elements.

The contact material 1 contains the second arc resistant component 4 in terms of mass ratio, for example, 5% by mass or more and 50% by mass or less, and further 10% by mass or more and 40% by mass or less with respect to the entire contact material 1. When the mass ratio of the second arc resistance component 4 contained in the contact material 1 is 5% by mass or more, the arc resistance of the contact material 1 increases. Further, when the mass ratio of the second arc-resistant component 4 is 50% by mass or less, the separation of the second arc-resistant component 4 from the contact material 1 and the generation of cracks on the surface of the contact material 1 are efficient. Is suppressed. Therefore, the withstand voltage characteristic and the cutoff characteristic of the contact material 1 are improved.

The additive component 5 formed in the conductive matrix 2 is composed of a plurality of particulate structures and is uniformly dispersed inside the conductive matrix 2. The additive component 5 is three-dimensionally surrounded by a plurality of structures constituting the first arc-resistant component 3c.

By the presence of the additive component 5 in the conductive matrix 2, the first arc-resistant component 3c is formed in the vicinity of the additive component 5. In other words, the first arc-resistant component 3c surrounds the additive component 5. The first arc-resistant component 3c is made finer than the raw material powder of the first arc-resistant component used when the contact material 1 is manufactured. Furthermore, the phase separation between the conductive matrix 2 and the first arc-resistant component 3 is suppressed. Therefore, the first arc-resistant component 3c formed in the conductive matrix 2 is miniaturized and made uniform. Therefore, the withstand voltage characteristic and the cutoff characteristic of the contact material 1 are improved.

The additive component 5 is composed of at least one substance selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum carbide, and tungsten carbide. Further, the additive component 5 may be composed of one kind of the above-mentioned substance, or may be composed of two or more kinds of substances.

The contact material 1 contains the additive component 5 in terms of mass ratio, for example, 0.1% by mass or more and 10% by mass or less, and further, 1% by mass or more and 5% by mass or less with respect to the entire contact material 1. When the mass ratio of the additive component 5 contained in the contact material 1 is 0.1% by mass or more, the miniaturization and homogenization of the first arc-resistant component 3c are efficiently improved. Therefore, the withstand voltage characteristic and the cutoff characteristic of the contact material 1 are improved.

Note that FIG. 1 shows an example in which a plurality of tissues formed by gathering together with respect to the second arc-resistant component 4 are surrounded by the first arc-resistant component 3b, but they are formed independently without gathering with each other. One structure may be surrounded by the first arc resistant component 3b. The same applies to the additive component 5, and one structure may be surrounded by the first arc-resistant component 3c.

Further, with respect to the first arc-resistant component 3, the second arc-resistant component 4, and the additive component 5, a plurality of particulate structures are independently composed as shown in FIG. 1, but a plurality of particulate structures are formed. Organization may be continuously composed. However, the abundance ratio of each continuously composed component is smaller than that of each independently composed component 3, 4, 5 with respect to the entire contact material 1.

Next, a method for manufacturing the contact material 1 for a vacuum valve according to the embodiment will be described.

In the method for producing the contact material 1, at least a heat treatment for producing a liquid phase of the conductive material is performed, as will be described later. The method for producing the contact material 1 is not particularly limited as long as the contact material 1 as shown in FIG. 1 can be produced by such heat treatment. The following shows some methods for manufacturing the contact material 1.

First, a method S10 for manufacturing the contact material 1 by the liquid phase sintering method will be described below.

The manufacturing method S10 of the contact material 1 by the liquid phase sintering method includes a step S11 for preparing a mixture (hereinafter, also referred to as a preparation step S11) and a step S12 (hereinafter, also referred to as a molding step S12) for obtaining a molded product of the mixture. It has a step S13 (hereinafter, also referred to as a heat treatment step S13) for heat-treating a molded body made of the mixture.

First, the preparation step S11 will be described.

The mixture prepared in the preparation step S11 is composed of a conductive material made of Cu, a first arc-resistant material made of Cr, a second arc-resistant material, and an additive material, and is a mixture of these materials. be. Further, the mixture may be produced by mixing commercially available products of each material, or may be produced by pulverizing and mixing the raw materials of each material. The conductive material, the first arc-resistant material, the second arc-resistant material, and the additive material are each in the form of particles.

The conductive material consists of a plurality of particles of Cu having conductivity. The average particle size of the conductive material is a median diameter (D ₅₀ ), for example, 0.1 μm or more and 150 μm or less, and further 30 μm or more and 70 μm or less. When the average particle size of the conductive material is 0.1 μm or more, the gas content of the contact material is suppressed. Further, when the average particle size of the conductive material is 150 μm or less, the dispersibility of the conductive material in the heat treatment step S13 increases. Therefore, the phase separation between the conductive matrix 2 and the first arc-resistant component 3 in the contact material 1 is suppressed.

In the following, unless otherwise specified, the average particle size of each material is represented by the median diameter (D ₅₀ ). The median diameter (D ₅₀ ) is a median diameter calculated as a particle size corresponding to 50% of the integrated distribution curve from the number-based particle size distribution.

The first arc resistant material is composed of a plurality of particles of Cr having arc resistance. The average particle size of the first arc-resistant material is, for example, 0.1 μm or more and 150 μm or less, and further 0.1 μm or more and 100 μm or less. When the average particle size of the first arc-resistant material is 0.1 μm or more, the gas content of the contact material is suppressed. Further, when the average particle size of the first arc-resistant material is 150 μm or less, the dispersibility of the first arc-resistant material in the heat treatment step S13 increases. Therefore, the phase separation between the conductive matrix 2 and the first arc-resistant component 3 is suppressed.

The second arc-resistant material is composed of a plurality of particles of the material having arc resistance and a melting point higher than the melting point of Cr. For example, the second arc resistant material is composed of at least one element selected from the group consisting of Nb and V. Further, the second arc-resistant material may be composed of one kind of the above-mentioned elements, or may be composed of two or more kinds of elements.

The average particle size of the second arc-resistant material is, for example, 0.1 μm or more and 150 μm or less, and further 30 μm or more and 70 μm or less. When the average particle size of the second arc-resistant material is 1 μm or more, the gas content of the contact material is suppressed. Further, when the average particle size of the second arc-resistant material is 150 μm or less, the dispersibility of the second arc-resistant material in the heat treatment step S13 increases. Therefore, the second arc-resistant component 4 is likely to be surrounded by the first arc-resistant component 3.

The additive material consists of a plurality of particles of the material having arc resistance. For example, the additive material is composed of at least one substance selected from the group consisting of Mo, W, molybdenum carbides, and tungsten carbides. Further, the additive material may be composed of one kind of the above-mentioned substance, or may be composed of two or more kinds of substances.

The average particle size of the added material is, for example, 0.1 μm or more and 10 μm or less, more preferably 0.5 μm or more and 5 μm or less. When the average particle size of the added material is 0.1 μm or more, the gas content of the contact material is suppressed. Further, when the average particle size of the added material is 10 μm or less, the dispersibility of the added material in the heat treatment step S13 increases, and the first arc-resistant component 3c is likely to be formed in the vicinity of the added component 5. Therefore, the miniaturization and homogenization of the first arc-resistant component 3c formed in the conductive matrix 2 is improved.

Further, the average particle size of the added material is preferably smaller than the average particle size of the first arc-resistant material, and the ratio of the average particle size of the added material to the average particle size of the first arc-resistant material (additional material). The average particle size of the first arc-resistant material) is more preferably 1/10 or less.

Next, the molding step S12 will be described.

In the molding step S12, the mixture prepared in the preparation step S11 is molded to obtain a molded product of the mixture. The molding method is not particularly limited as long as a molded product can be obtained. For example, by placing the mixture in a mold having a predetermined shape and pressurizing the mixture at a predetermined pressure, a molded product which is a green compact of the mixture can be produced.

Next, the heat treatment step S13 will be described.

In the heat treatment step S13, the molded body made of the mixture is heated to a temperature 100 ° C. lower (T _Cu -100 ° C.) or higher than the melting point T _Cu (1083 ° C.) of Cu, which is a conductive material, or 200 ° C. higher than T _Cu (T _Cu +200). ℃) Heat below. The heat treatment of the molded product is performed in a non-oxidizing atmosphere such as a vacuum atmosphere.

When the molded product is heated in the above temperature range, the conductive material made of Cu melts to form a liquid phase of Cu. At this time, at least a part of the first arc-resistant material is solid-solved in the Cu melt. In addition, the second arc-resistant material and the additive material do not melt. Then, the first arc-resistant component 3 which was solid-dissolved in the melt by cooling the molded body is the periphery of the second arc-resistant component 4, the periphery of the additive component 5, and the second arc-resistant component. It precipitates in the melt other than around 4 and the additive component 5, and Cu is solidified. As a result, as shown in FIG. 1, a contact point composed of a conductive matrix 2 and a first arc-resistant component 3, a second arc-resistant component 4, and an additive component 5 formed in the conductive matrix 2. Material 1 can be manufactured.

By heat-treating the molded body in this way, the conductive material is the conductive matrix 2 in the contact material 1, the first arc-resistant material is the first arc-resistant component 3, and the second arc-resistant material is the second arc-resistant material. The arcuate component 4 and the additive material are the additive component 5.

Here, when the heating temperature of the molded product is T _Cu -100 ° C. or higher, the first arc-resistant material is likely to dissolve in the conductive material. When the heating temperature of the molded product is T _Cu + 200 ° C. or lower, the shape of the molded product is maintained during heating.

The heating time of the molded product at the above-mentioned heating temperature is more preferably 0.5 hours or more and 10 hours or less, for example. When the heating time of the molded product is 0.5 hours or more, the first arc-resistant material is sufficiently dissolved in the conductive material.

Next, a method S20 for manufacturing the contact material 1 by the sintering and infiltration method will be described below.

The method S20 for manufacturing the contact material 1 by the sintering and infiltration method includes a step S21 for preparing a mixture (hereinafter, also referred to as a preparation step S21) and a step S22 for obtaining a molded product of the mixture (hereinafter, also referred to as a molding step S22). The step S23 (hereinafter, also referred to as a leaching step S23) of immersing the conductive material in the molded body is provided.

First, the preparation step S21 will be described.

The mixture prepared in the preparation step S21 is a mixture of a material containing a first arc-resistant material made of Cr, a second arc-resistant material, and an additive material. Similar to the preparation step S11, the mixture prepared in the preparation step S21 may be produced by mixing commercially available products, or may be produced by pulverizing and mixing raw materials.

Next, the molding step S22 will be described.

In the molding step S22, the mixture obtained in the preparation step S21 is molded to obtain a molded product. Similar to the molding step S12, the molding method of the molding step S22 is not particularly limited.

Next, the infiltration step S23 will be described.

In the infiltration step S23, a melt of a conductive material made of Cu is infiltrated into the molded body.

The method for infiltrating the conductive material is not particularly limited as long as the contact material can be produced. For example, a conductive material such as a plate or particles is installed on at least one of the upper surface and the lower surface of the molded body so that the conductive material and the molded body come into contact with each other. Subsequently, the conductive material and the molded product are heated to T _Cu -100 ° C. or higher and T _Cu + 200 ° C. or lower in the same manner as in the heat treatment step S13 described above. The heat treatment of the conductive material and the molded product in the infiltration is performed, for example, in a non-oxidizing atmosphere.

When the conductive material and the molded product are heated in the above temperature range, the conductive material melts and a liquid phase of Cu is formed. The Cu melt enters the pores present in the molded product. At this time, at least a part of the first arc-resistant material is solid-solved in the Cu melt. In addition, the second arc-resistant material and the additive material do not melt. Then, by cooling the molded body, Cu is solidified and the contact material 1 is obtained.

The heating time of the conductive material and the molded product at the above-mentioned heating temperature is, for example, 0.5 hours or more and 10 hours or less. When the heating time of the conductive material is 0.5 h or more, the melt of the conductive material sufficiently permeates into the molded body, and the first arc-resistant material is sufficiently dissolved in the conductive material.

Here, in the manufacturing method S20 by the sintering and infiltration method, an example in which the conductive material is not contained in the mixture prepared in the preparation step S21 has been described, but the conductive material may be contained in the mixture.

Next, the manufacturing method S30 of the contact material 1 by the melting method will be described below.

The method S30 for producing the contact material 1 by the melting method includes a preparation step S11 and a step S32 for heat-treating the mixture (hereinafter, also referred to as a heat treatment step S32).

The preparation step S11 of the manufacturing method S30 is the same as the preparation step S11 of the manufacturing method S10 described above.

Next, the heat treatment step S32 will be described.

In the heat treatment step S32, the mixture obtained in the preparation step S11 is heated to a melting point T _Cr or higher of Cr, which is the first arc resistant material. The heat treatment of the mixture is carried out, for example, in a non-oxidizing atmosphere.

When the mixture is heated in the above temperature range, the conductive material and the first arc resistant material are melted to form a liquid phase of Cu and Cr. At this time, at least a part of Cr is dissolved in the Cu melt. In addition, the second arc-resistant material and the additive material do not melt.

Subsequently, by cooling the melt, Cr that had been solid-dissolved in the Cu melt was formed around the second arc-resistant component, around the additive component, and in the second arc-resistant component 4 and the additive component 5. Precipitated in a melt of Cu other than the surroundings, Cu is solidified, and the contact material 1 is obtained.

Here, when the heating temperature of the mixture is T _Cr or higher, the first arc-resistant material is surely melted, so that the first arc-resistant material is easily dissolved in the Cu melt.

The heating time of the mixture at the above heating temperature is, for example, 0.5 hours or more and 10 hours or less. When the heating time of the mixture is 0.5 hours or more, the gas contained in the mixture decreases, so that the gas content of the contact material decreases.

Further, the manufacturing method S30 may further include a step S33 (hereinafter, also referred to as a heating step S33) for heating the contact material after the heat treatment step S32.

In the heating step S33, the contact material obtained in the heat treatment step S32 is heated to a temperature lower than or lower than T _Cu , preferably 400 ° C. lower than T _Cu (T _Cu −400 ° C.) or higher and 20 ° C. lower than T _Cu (T _Cu -20 ° C.). ) Heat below. When the contact material 1 is heated in the above temperature range, the residual stress of the contact material decreases, so that the dielectric breakdown voltage of the contact material increases. The heat treatment of the contact material is performed, for example, in a non-oxidizing atmosphere.

Further, the heating time of the contact material at the heating temperature of the heating step S33 is, for example, 0.5 hours or more and 10 hours or less. When the heating time of the contact material is 0.5 hours or more, the residual stress of the contact material is sufficiently reduced.

Next, a method S40 for manufacturing the contact material 1 by a liquid phase sintering method in which sintering and pressurization of the sintered body are repeated will be described below.

The manufacturing method S40 includes a preparation step S11, a molding step S12, a step S43 for sintering the molded body (hereinafter, also referred to as a sintering step S43), and a step S44 for pressurizing the sintered body (hereinafter, pressurizing step S44). Also referred to as), and a step S45 (hereinafter, also referred to as a heat treatment step S45) for heat-treating the pressed sintered body.

The preparation step S11 and the molding step S12 of the manufacturing method S40 are the same as the preparation step S11 and the molding step S12 of the manufacturing method S10 described above, respectively.

Next, the sintering step S43 will be described.

In the sintering step S43, the molded body obtained in the molding step S12 is heated to sinter the molded body to obtain a sintered body. The method for sintering the molded product is not particularly limited as long as the sintered body can be obtained. Sintering of the molded product is performed, for example, in a non-oxidizing atmosphere.

The heating temperature of the molded product is, for example, 800 ° C. or higher and 1300 ° C. or lower, and further 1000 ° C. or higher and 1250 ° C. or lower. When the heating temperature of the molded product is 800 ° C. or higher, the sinterability is improved. When the heating temperature of the molded product is 1300 ° C. or lower, the materials constituting the molded product do not melt and the molded product is sintered.

Further, the heating time of the molded product at the above-mentioned heating temperature is, for example, 0.5 hours or more and 10 hours or less. When the heating time of the molded product is 0.5 hours or more, the sinterability is improved.

Next, the pressurizing step S44 will be described.

In the pressurizing step S44, the sintered body obtained in the sintering step S43 is pressurized. By pressurizing the sintered body, the sintered body is compressed. Therefore, the size of the sintered body after pressurization is smaller than that of the sintered body before pressurization. The method for pressurizing the sintered body is not particularly limited as long as the sintered body can be compressed. For example, a compressed sintered body can be obtained by pressurizing the sintered body with a pressure molding machine.

The force for pressurizing the sintered body is, for example, 0.1 t / cm ² or more and 15 t / cm ² or less, and further 1 t / cm ² or more and 10 t / cm ² or less. When the force for pressurizing the sintered body is 0.1 t / cm ² or more, the sintered body is compressed and the pores contained in the sintered body are reduced. When the force for pressurizing the sintered body is 15 t / cm ² or less, damage to the sintered body due to pressurization is suppressed.

Next, the heat treatment step S45 will be described.

In the heat treatment step S45, the sintered body pressurized by the pressurizing step S44 is heat-treated. In this heat treatment, the sintered body composed of the mixture is heated to T _Cu -100 ° C. or higher and T _Cu + 200 ° C. or lower. The difference between the heat treatment step S45 and the above-mentioned heat treatment step S13 is that the heat treatment step S45 heat-treats the sintered body, whereas the heat treatment step S13 heat-treats the molded body.

In the heat treatment step S45, a pressed and compressed sintered body, that is, a sintered body having a reduced porosity is heat-treated. Therefore, for the contact material, the electrical conductivity increases and the gas content decreases.

In the manufacturing method S40, the sintering step S43 and the pressurizing step S44 may be repeated a plurality of times. That is, the sintered body pressurized in the pressurizing step S44 may be sintered again in the sintering step S43. By repeating the sintering step S43 and the pressurizing step S44 a plurality of times in this way, the electrical conductivity of the contact material is further increased, and the gas content is further lowered.

As described above, the contact material can be manufactured by various manufacturing methods. Then, the method for manufacturing the contact material can be appropriately selected according to the required characteristics of the contact material, the type of the material used for manufacturing the contact material, and the like.

Next, the vacuum valve provided with the contact material 1 (1a, 1b) for the vacuum valve of the embodiment will be described.

FIG. 2 is a cross-sectional view schematically showing a vacuum valve 21 including the contact materials 1a and 1b for the vacuum valve of the embodiment. FIG. 3 is an enlarged cross-sectional view schematically showing the contact configuration of the vacuum valve 21 provided with the contact materials 1a and 1b for the vacuum valve of the embodiment.

As shown in FIG. 2, the sealing metal fittings 23a on the fixed side and the sealing metal fittings 23b on the movable side are provided on the opening surfaces at both ends of the tubular vacuum insulating container 22 by brazing, respectively. A current-carrying shaft 24a on the fixed side is pierced and fixed to the sealing metal fitting 23a on the fixed side.

As shown in FIG. 3, the electrode 25a on the fixed side is fixed to the lower end of the current-carrying shaft 24a on the fixed side by the brazing material 26a. Further, the contact material 1a on the fixed side is fixed to the lower surface of the electrode 25a on the fixed side by the brazing material 27a. The electrode 25a on the fixed side may be crimped to the current-carrying shaft 24a on the fixed side by caulking or the like.

Further, the contact material 1b on the movable side is fixed to the upper surface of the electrode 25b on the movable side by the brazing material 27b so as to be in contact with and detachable from the contact material 1a on the fixed side. The movable side electrode 25b is fixed to the upper end portion of the movable side energizing shaft 24b by the brazing material 26b. The movable electrode 25b may be crimp-connected to the movable current-carrying shaft 24b by caulking or the like.

Further, as shown in FIG. 2, the current-carrying shaft 24b on the movable side movably penetrates the central opening of the sealing metal fitting 23b on the movable side. A stretchable bellows 28 is provided by brazing between the current-carrying shaft 24b on the movable side and the opening of the sealing metal fitting 23b on the movable side.

Further, a support member 30 is brazed to the outer periphery of the cylindrical arc shield 29 that surrounds the contact material 1a on the fixed side and the contact material 1b on the movable side. The support member 30 is fixed to a protruding portion 22a protruding from the inner surface of the vacuum insulating container 22.

Since the vacuum valve 21 has such a configuration, the contact material 1a on the movable side can be brought into contact with and detached from the contact material 1b on the fixed side while keeping the inside of the vacuum insulating container 22 in a vacuum.

The vacuum valve 21 can be applied to, for example, a vacuum breaker. When the contact materials 1a and 1b having improved withstand voltage characteristics and breaking characteristics are used for the switch of the vacuum circuit breaker, the characteristics of the vacuum circuit breaker are improved.

As described above, according to the contact material of the embodiment and the method for producing the contact material, the contact material includes a second arc resistant component and an additive component surrounded by the first arc resistant component. By surrounding the second arc-resistant component with the first arc-resistant component, the detachment of the second arc-resistant component from the contact material and the occurrence of cracks on the surface of the contact material are suppressed. Further, by surrounding the added component with the first arc-resistant component, the miniaturization and uniformity of the first arc-resistant component formed in the conductive matrix are improved. Therefore, the withstand voltage characteristics and the cutoff characteristics of the contact material are improved.

According to the embodiment described above, even if a substance having excellent withstand voltage characteristics and improving arc resistance is contained, detachment of the substance and generation of cracks on the surface due to an impact at the time of current interruption are suppressed. It is possible to provide a contact material for a vacuum valve and a method for manufacturing a contact material for a vacuum valve.

Hereinafter, a detailed description will be given with reference to examples. The present invention is not limited to these examples.

(Example 1)
In Example 1, the contact material E1 of Cu-30Cr-15Nb-1Mo was produced by the liquid phase sintering method. The number before the element symbol indicates mass%. The manufacturing method of the contact material E1 is shown below.

First, Cu particles having an average particle size of 70 μm, Cr particles having an average particle size of 100 μm, Nb particles having an average particle size of 50 μm, and Mo particles having an average particle size of 1 μm are mixed at a mass ratio of 54:30:15: 1, and Cu is used. A mixture consisting of particles, Cr particles, Nb particles and Mo particles was obtained.

Subsequently, the mixture was placed in a mold having an inner diameter of 25 mm. Then, the mixture was pressed with a pressure of 10 t / cm ² to obtain a molded product.

Subsequently, the molded product was heated at 1200 ° C. for 5 hours in a hydrogen atmosphere to melt Cu. The heating temperature of 1200 ° C. at this time was 117 ° C. higher than that of T _Cu . Then, the heated molded product was naturally cooled. In this way, the contact material E1 was obtained.

FIG. 4 is an SEM image of a cross section of the contact material E1. Further, FIG. 5 is an image in which the Cu element in the cross section of the contact material E1 is mapped, FIG. 6 is an image in which the Cr element in the cross section of the contact material E1 is mapped, and FIG. 7 is an image in which the Cr element in the cross section of the contact material E1 is mapped. It is an image which mapped the Mo element.

Specifically, FIG. 4 shows an image in which the manufactured contact material E1 is cut and the cut surface of the contact material E1 is observed by SEM. Further, the SEM images of FIG. 4 are shown in FIGS. 5 to 7 in which element mapping is performed by EPMA (electron probe microanalyzer). With respect to FIGS. 5 to 7, the higher the concentration of each element in the observed portion, the whiter (lighter color) the portion, and the lower the concentration of each element, the blacker (darker) the relevant portion.

From FIGS. 5 to 7, the first arc-resistant component made of Cr and the additive component made of Mo were formed in the conductive matrix made of Cu, and the added component was surrounded by the first arc-resistant component. Further, although not shown in the figure, the second arc-resistant component composed of Nb was formed in the conductive matrix and surrounded by the first arc-resistant component. Further, the first arc-resistant component which is dispersed alone in the conductive matrix without surrounding the second arc-resistant component and the added component was also formed.

Moreover, the hardness of the contact material E1 was measured. Specifically, the manufactured contact material E1 was cut, and the Rockwell hardness (HRB) of the cut surface of the contact material E1 was measured. As a result, the HRB of the contact material E1 was 30.

In addition, the contact material E1 was tested for withstand voltage characteristics. Specifically, in the test of withstand voltage characteristics, the contact material E1 processed into a cylinder having a diameter of 20 mm and a thickness of 3 mm was placed facing each other through a gap of 1 mm in a vacuum chamber simulating the vacuum valve shown in FIG. , The dielectric breakdown voltage was measured 10 times, and the arithmetic average value of the 10 measured values was calculated as the dielectric breakdown voltage. With the dielectric breakdown voltage of the contact material C1 of Comparative Example 1 described later as 1 (reference), the breakdown voltage of the contact material E1 was 1.2 times, and the withstand voltage characteristic of the contact material E1 was improved.

(Example 2)
In Example 2, the contact material E2 of Cu-30Cr-15Nb-1Mo was produced by the sintering and infiltration method. The manufacturing method of the contact material E2 is shown below.

First, Cu particles having an average particle size of 70 μm, Cr particles having an average particle size of 100 μm, Nb particles having an average particle size of 50 μm, and Mo particles having an average particle size of 1 μm are mixed at a mass ratio of 23.4: 50: 25: 1.6. Then, a mixture consisting of Cu particles, Cr particles, Nb particles and Mo particles was obtained.

Subsequently, the mixture was placed in a mold having an inner diameter of 25 mm. Then, the mixture was pressurized to obtain a molded product having a relative density of 59 to 61% (60 ± 1%).

Subsequently, a plate-shaped Cu piece was placed on the upper surface of the molded body. Then, in a hydrogen atmosphere, the molded body and the Cu piece were heated at 1200 ° C. to melt the Cu piece, so that Cu was infiltrated into the molded body. Then, the molded product in which Cu was infiltrated was naturally cooled. In this way, the contact material E2 was obtained.

The contact material E2 was observed by SEM and EPMA. As a result, in the contact material E2, the same structure as that of the contact material E1 was observed.

Further, as in Example 1, the hardness of the contact material E2 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material E2 was 35. Further, the dielectric breakdown voltage of the contact material E2 was 1.3 times higher than the dielectric breakdown voltage of the contact material C1 described later, and the withstand voltage characteristic of the contact material E2 was improved.

(Comparative Example 1)
In Comparative Example 1, the contact material C1 of Cu-30Cr-15Nb-1Mo was produced by the solid phase sintering method. The manufacturing method of the contact material C1 is shown below.

First, a mixture was obtained in the same manner as in Example 1 to obtain a molded product.

Subsequently, the molded product was heated at 1050 ° C. for 1 hour in a hydrogen atmosphere to sinter the molded product. The heating temperature of 1050 ° C. at this time was 33 ° C. lower than that of T _Cu . Further, in this heat treatment, a liquid phase of Cu particles was not generated. Then, the heated molded product was naturally cooled. In this way, the contact material C1 was obtained.

Contact material C1 was observed by SEM and EPMA. As a result, in the contact material C1, the second arc-resistant component made of Nb and the additive component made of Mo are not surrounded by the first arc-resistant component made of Cr, and the first arc-resistant component and the second arc-resistant component. The arc-resistant component and the additive component were dispersed in the conductive matrix made of Cu. The structure of the first arc-resistant component is almost the same as the shape and size of the Cr particles as the raw material, and the structure of the second arc-resistant component is almost the same as the shape and size of the Nb particles. The texture of the components was similar to the shape and size of the Mo particles.

Further, as in Example 1, the hardness of the contact material C1 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material C1 was 20.

As described above, since the first arc-resistant component covers the circumference of the second arc-resistant component, the hardness of the contact materials E1 to E2 is improved as compared with the contact material C1. Therefore, the detachment of the second arc-resistant component from the contact materials E1 to E2 and the generation of cracks on the surfaces of the contact materials E1 to E2 were suppressed. Further, since the first arc-resistant component covers the periphery of the added component, the first arc-resistant component is finely and uniformly precipitated as compared with the contact material C1. Therefore, the withstand voltage characteristics of the contact materials E1 and E2 are improved.

(Example 3)
In Example 3, the contact material E3 of Cu-25Cr-5Nb-1Mo _2C was produced by the dissolution method. The manufacturing method of the contact material E3 is shown below.

First, Cu particles having an average particle size of 50 μm, Cr particles having an average particle size of 100 μm, Nb particles having an average particle size of 50 μm, and Mo ₂ C particles having an average particle size of 1 μm are mixed at a mass ratio of 69: 25: 5: 1. , Cu particles, Cr particles, Nb particles and Mo ₂ C particles were obtained.

Subsequently, 3 kg of the mixture was placed in an alumina crucible. The mixture was then heated at about 1800 ° C. in an argon atmosphere reduced to 400 Torr. Then, the melt was poured into a mold and rapidly cooled. In this way, the contact material E3 was obtained.

The contact material E3 was observed by SEM and EPMA. As a result, the second arc-resistant component made of Nb and the additive component made of Mo ₂ C were surrounded by the first arc-resistant component made of Cr. Further, the first arc-resistant component which is dispersed alone in the conductive matrix made of Cu without surrounding the second arc-resistant component and the added component was also formed.

Further, as in Example 1, the hardness of the contact material E3 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material E3 was 35. Further, the dielectric breakdown voltage of the contact material E3 was 1.4 times that of the dielectric breakdown voltage of the contact material C2 of Comparative Example 2 described later, and the withstand voltage characteristic of the contact material E3 was improved.

(Example 4)
In Example 4, the contact material E4 of Cu-25Cr-5Nb-1Mo _2C was produced by the dissolution method. The manufacturing method of the contact material E4 is shown below.

First, the contact material E3 was obtained in the same manner as in Example 3.

Subsequently, the contact material E3 was heated at 800 ° C. in a hydrogen atmosphere. The heating temperature of 800 ° C. at this time was 283 ° C. lower than that of T _Cu . After that, the heated contact material was naturally cooled. In this way, the contact material E4 was obtained.

The contact material E4 was observed by SEM and EPMA. As a result, in the contact material E4, the same structure as that of the contact material E3 was observed.

Further, in the same manner as in Example 1, the hardness of the contact material E4 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material E4 was 33. Further, the dielectric breakdown voltage of the contact material E4 was 1.5 times higher than that of the contact material C2, which will be described later, and the withstand voltage characteristic of the contact material E4 was improved.

(Comparative Example 2)
In Comparative Example 2, the contact material C2 of Cu-25Cr-5Nb-1Mo _2C was produced by the solid phase sintering method. The manufacturing method of the contact material C2 is shown below.

First, a mixture was obtained in the same manner as in Example 3.

Subsequently, the mixture was placed in a mold having an inner diameter of 25 mm. Then, the mixture was pressed with a pressure of 10 t / cm ² to obtain a molded product.

Subsequently, the molded product was heated at 1050 ° C. for 1 hour in a hydrogen atmosphere to sinter the molded product. Then, the heated molded product was naturally cooled. In this way, the contact material C2 was obtained.

Contact material C2 was observed by SEM and EPMA. As a result, in the contact material C2, the second arc-resistant component made of Nb and the additive component made of Mo ₂ C are not surrounded by the first arc-resistant component made of Cr, and are not surrounded by the first arc-resistant component. The second arc-resistant component and the added component were dispersed in the conductive matrix made of Cu.

Further, as in Example 1, the hardness of the contact material C2 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material C2 was lower than 33.

As described above, since the first arc-resistant component covers the circumference of the second arc-resistant component and the surrounding of the additive component, the hardness and withstand voltage characteristics of the contact materials E3 to E4 are compared with those of the contact material C2. Has improved. Further, in the contact material E4 obtained by heat-treating the contact material E3, the residual stress was reduced, so that the withstand voltage characteristics were further improved.

(Example 5)
In Example 5, the contact material E5 of Cu-20Cr-10V-0.5W was produced by a liquid phase sintering method in which sintering and pressurization of the sintered body were repeated. The manufacturing method of the contact material E5 is shown below.

First, Cu particles having an average particle size of 50 μm, Cr particles having an average particle size of 100 μm, V particles having an average particle size of 50 μm, and W particles having an average particle size of 0.1 μm are mixed in a mass ratio of 69.5: 20: 10: 0.5. To obtain a mixture consisting of Cu particles, Cr particles, V particles, and W particles.

Subsequently, the mixture was placed in a mold having an inner diameter of 25 mm. Then, the mixture was pressed with a pressure of 3 t / cm ² to obtain a molded product.

Subsequently, the molded product was heated at 1000 ° C. for 2 hours in a vacuum atmosphere to sinter the molded product. The heating temperature of 1000 ° C. at this time was 83 ° C. lower than that of T _Cu . Then, the heated molded product was naturally cooled. In this way, a sintered body was obtained.

Subsequently, the sintered body was pressurized and compressed at a pressure of 10 t / cm ² .

Subsequently, the pressurized sintered body was heated at 1250 ° C. for 2 hours in a vacuum atmosphere to dissolve Cu. The heating temperature of 1250 ° C. at this time was 167 ° C. higher than that of T _Cu . Then, the heated sintered body was naturally cooled. In this way, the contact material E5 was obtained.

The contact material E5 was observed by SEM and EPMA. As a result, the second arc-resistant component made of V and the additive component made of W were surrounded by the first arc-resistant component made of Cr. Further, the first arc-resistant component which is dispersed alone in the conductive matrix made of Cu without surrounding the second arc-resistant component and the added component was also formed. Further, the size of the structure of the first arc-resistant component surrounding the added component and the size of the structure of the first arc-resistant component dispersed independently were substantially the same.

Further, in the same manner as in Example 1, the hardness of the contact material E5 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material E5 was 30. Further, the dielectric breakdown voltage of the contact material E5 was 1.6 times higher than the dielectric breakdown voltage of the contact material C3 of Comparative Example 3 described later, and the withstand voltage characteristic of the contact material E5 was improved.

(Comparative Example 3)
In Comparative Example 3, the contact material C3 of Cu-20Cr-10V-0.5W was produced by the solid phase sintering method. The manufacturing method of the contact material C3 is shown below.

First, a mixture was obtained in the same manner as in Example 5.

Subsequently, the mixture was placed in a mold having an inner diameter of 25 mm. Then, the mixture was pressed with a pressure of 10 t / cm ² to obtain a molded product.

Subsequently, the molded product was heated at 1050 ° C. for 1 hour in a hydrogen atmosphere to sinter the molded product. Then, the heated molded product was naturally cooled. In this way, the contact material C3 was obtained.

Contact material C3 was observed by SEM and EPMA. As a result, in the contact material C3, the second arc resistant component composed of V and the additive component composed of W are not surrounded by the first arc resistant component composed of Cr, and the first arc resistant component and the second arc resistant component are present. The arc-resistant component and the additive component were dispersed in the conductive matrix made of Cu.

Further, as in Example 1, the hardness of the contact material C3 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material C2 was lower than 30.

In this way, in addition to the first arc-resistant component wrapping around the second arc-resistant component and around the additive component, it is formed independently of the structure of the first arc-resistant component surrounding the additive component. Since the structure of the first arc-resistant component is almost the same size, the hardness and withstand voltage characteristics of the contact material E5 are improved as compared with the contact material C3.

(Example 6)
In Example 6, the contact material E6 of Cu-25Cr-10V-2WC was produced by the liquid phase sintering method. The manufacturing method of the contact material E6 is shown below.

First, Cu particles having an average particle size of 50 μm, Cr particles having an average particle size of 70 μm, V particles having an average particle size of 30 μm, and WC particles having an average particle size of 10 μm are mixed at a mass ratio of 63:25: 10: 2, and Cu is used. A mixture consisting of particles, Cr particles, V particles and WC particles was obtained.

Subsequently, the mixture was placed in a mold having an inner diameter of 25 mm. Then, the mixture was pressed with a pressure of 15 t / cm ² to obtain a molded product.

Subsequently, the molded product was heated at 1100 ° C. for 0.5 hours in a hydrogen atmosphere to melt Cu. The heating temperature of 1100 ° C. at this time was 17 ° C. higher than that of T _Cu . Then, the heated molded product was naturally cooled. In this way, the contact material E6 was obtained.

The contact material E6 was observed by SEM and EPMA. As a result, the second arc-resistant component made of V and the additive component made of WC were surrounded by the first arc-resistant component made of Cr. Further, the first arc-resistant component which is dispersed alone in the conductive matrix made of Cu without surrounding the second arc-resistant component and the added component was also formed.

Further, in the same manner as in Example 1, the hardness of the contact material E6 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material E6 was 32. Further, the dielectric breakdown voltage of the contact material E6 was 1.4 times higher than the dielectric breakdown voltage of the contact material C4 of Comparative Example 4 described later, and the withstand voltage characteristic of the contact material E6 was improved.

(Example 7)
In Example 7, the contact material E7 of Cu-25Cr-10V-2WC was carried out by the same method as in Example 6 except that the WC particles having an average particle size of 10 μm in Example 6 were changed to WC particles having an average particle size of 1 μm. Manufactured.

The contact material E7 was observed by SEM and EPMA. As a result, in the contact material E7, basically the same structure as that of the contact material E6 was observed. Specifically, in the contact material E7, the structure of the additive component made of WC was finer than that of the contact material E6, and the structure of the first arc-resistant component surrounding the additive component was finer.

Further, in the same manner as in Example 1, the hardness of the contact material E7 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material E7 was 35. Further, the dielectric breakdown voltage of the contact material E7 was 1.6 times based on the dielectric breakdown voltage of the contact material C4 described later, and the withstand voltage characteristic of the contact material E7 was improved.

(Comparative Example 4)
In Comparative Example 4, the contact material C4 of Cu-25Cr-10V-2WC was produced by the solid phase sintering method. The manufacturing method of the contact material C4 is shown below.

First, a mixture was obtained in the same manner as in Example 6.

Subsequently, the mixture was placed in a mold having an inner diameter of 25 mm. Then, the mixture was pressed with a pressure of 10 t / cm ² to obtain a molded product.

Subsequently, the molded product was heated at 1050 ° C. for 1 hour in a hydrogen atmosphere to sinter the molded product. Then, the heated molded product was naturally cooled. In this way, the contact material C4 was obtained.

Contact material C4 was observed by SEM and EPMA. As a result, in the contact material C4, the second arc resistant component composed of V and the additive component composed of WC are not surrounded by the first arc resistant component composed of Cr, and the first arc resistant component and the second arc resistant component are present. The arc-resistant component and the additive component were dispersed in the conductive matrix made of Cu.

Further, in the same manner as in Example 1, the hardness of the contact material C4 was measured and the withstand voltage characteristics were tested. As a result, the HRB of the contact material C4 was lower than 35.

As described above, since the first arc-resistant component covers the circumference of the second arc-resistant component and the surrounding of the additive component, the hardness and withstand voltage characteristics of the contact materials E6 to E7 are compared with those of the contact material C4. Has improved. Further, by making the average particle size of the WC particles used in the contact material E7 1/10 or less of the average particle size of the Cr particles, the withstand voltage characteristics of the contact material E7 were further improved.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1,1a, 1b ... Contact material for vacuum valve, 2 ... Conductive matrix, 3,3a, 3b, 3c ... First arc resistant component, 4 ... Second arc resistant component, 5 ... Additive component, 21 ... Vacuum Valve, 22 ... Vacuum insulated container, 22a ... Projection, 23a, 23b ... Sealing metal fittings, 24a, 24b ... Energizing shaft, 25a, 25b ... Electrodes, 26a, 26b, 27a, 27b ... Wax material, 28 ... Bellows, 29 ... arc shield, 30 ... support member.

Claims (10)

A conductive matrix made of copper and
A particulate first arc-resistant component made of chromium formed in the conductive matrix and
A particulate second arc-resistant component formed in the conductive matrix, surrounded by the first arc-resistant component, and composed of at least one element selected from the group consisting of niobium and vanadium .
Addition in the form of particles formed in the conductive matrix, surrounded by the first arc-resistant component , and composed of at least one substance selected from the group consisting of molybdenum, tungsten, molybdenum carbide, and tungsten carbide. Consists of ingredients ,
A contact material for a vacuum valve, characterized in that the average particle size of the added component is smaller than the average particle size of the second arc-resistant component . The second arc-resistant component contains niobium and contains niobium.
The contact material for a vacuum valve according to claim 1, wherein the additive component contains molybdenum carbide. The second arc-resistant component contains vanadium and contains vanadium.
The contact material for a vacuum valve according to claim 1, wherein the additive component contains tungsten or a tungsten carbide. A second arc-resistant material composed of a conductive material made of copper, a first arc-resistant material made of chromium, a second arc-resistant material composed of at least one element selected from the group consisting of niobium and vanadium , and molybdenum, tungsten, and molybdenum carbides. And a step of preparing a mixture consisting of an additive material composed of at least one substance selected from the group consisting of tungsten carbide , and
The mixture is heat-treated to form a conductive matrix made of copper, a particulate first arc-resistant component made of chromium formed in the conductive matrix, and the first arc-resistant component formed in the conductive matrix. A particulate second arc-resistant component surrounded by an arc-resistant component and composed of at least one element selected from the group consisting of niobium and vanadium , and the first arc-resistant component formed in the conductive matrix. A contact material for a vacuum valve surrounded by an arc resistant component and composed of a particulate additive component composed of at least one substance selected from the group consisting of molybdenum, tungsten, molybdenum carbide, and tungsten carbide . Has a step to obtain ,
A method for producing a contact material for a vacuum valve , wherein the average particle size of the added component is smaller than the average particle size of the second arc-resistant component . The method for producing a contact material for a vacuum valve according to claim 4 , wherein in the step of obtaining the contact material for a vacuum valve, the mixture is heated to a temperature equal to or higher than the melting point of the first arc-resistant material. Further comprising a step of molding the mixture prepared in the step of preparing the mixture to obtain a molded product.
In the step of obtaining the contact material for a vacuum valve, the molded body made of the mixture is 100 ° C. lower than the melting point T of the conductive material (T-100 ° C.) or higher and 200 ° C. higher than the melting point T of the conductive material. The method for manufacturing a contact material for a vacuum valve according to claim 4 , wherein the material is heated to a temperature (T + 200 ° C.) or lower. A step of molding the mixture prepared in the step of preparing the mixture to obtain a molded product, and a step of obtaining a molded product.
A step of sintering the molded body obtained in the step of obtaining the molded body to obtain a sintered body, and a step of obtaining the sintered body.
It further includes a step of pressurizing the sintered body obtained in the step of obtaining the sintered body.
In the step of obtaining the contact material for a vacuum valve, the sintered body made of the mixture is heated to a temperature 100 ° C. lower than the melting point T of the conductive material (T-100 ° C.) or higher and 200 ° C. from the melting point T of the conductive material. The method for manufacturing a contact material for a vacuum valve according to claim 4 , wherein the material is heated to a high temperature (T + 200 ° C.) or lower. From the group consisting of molybdenum, tungsten, molybdenum carbide, and tungsten carbide, the first arc resistant material composed of chromium and the second arc resistant material composed of at least one element selected from the group consisting of niobium and vanadium . A step of preparing a mixture containing an additive material composed of at least one selected substance , and
The step of molding the mixture to obtain a molded body and
A melt of a conductive material made of copper is impregnated into the molded body, and a conductive matrix made of copper, a particle-like first arc-resistant component made of chromium formed in the conductive matrix, and the above-mentioned A particulate second arc-resistant component formed in a conductive matrix, surrounded by the first arc-resistant component, and composed of at least one element selected from the group consisting of niobium and vanadium, and the above-mentioned second arc-resistant component. A particulate additive component formed in a conductive matrix, surrounded by the first arc resistant component , and composed of at least one substance selected from the group consisting of molybdenum, tungsten, molybdenum carbides, and tungsten carbides. Has a process of obtaining contact materials for vacuum valves composed of
A method for producing a contact material for a vacuum valve , wherein the average particle size of the added component is smaller than the average particle size of the second arc-resistant component . The second arc-resistant component contains niobium and contains niobium.
The method for producing a contact material for a vacuum valve according to any one of claims 4 to 8, wherein the additive component contains molybdenum carbide. The second arc-resistant component contains vanadium and contains vanadium.
The method for producing a contact material for a vacuum valve according to any one of claims 4 to 8, wherein the additive component contains tungsten or a tungsten carbide.

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