JP2009252550A - Contact material, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact material for combining cut-off performance, withstand voltage performance and weld releasing performance, and to provide a manufacturing method thereof. <P>SOLUTION: The contact material consists of Cu, Cr, Te. Cr particles, Cu-Cr-Te particles in which Te-Cu-Cr phases and Cu-Te phases are mixed, and Cr-Te particles are dispersed in a base material mainly consisting of Cu, where Te-containing phases are formed in particle boundaries between the base material and the Cr particles and a Cr content is 40-50 mass%, a Te content is 0.1-2.0 mass%, and the rest is Cu. In the manufacturing method, mixed powder is filled in a sintering mold, and pulse energization pressure sintering is applied thereto at a temperature of 700-1,080°C and a pressure of 30-200 MPa. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a contact material and a manufacturing method thereof, and more particularly to a contact material suitable for a vacuum valve used for a vacuum circuit breaker and the like and a manufacturing method thereof.

  The demand for larger capacity, higher pressure resistance, and smaller size of circuit breakers, especially vacuum circuit breakers, has become more severe, and it is desired to improve the performance of vacuum valves mounted in vacuum circuit breakers. In a vacuum valve, a fixed electrode and a movable electrode are coaxially opposed to each other in an insulating container maintained at a high vacuum, and the movable electrode is connected to an operation mechanism unit via a bellows so as to move in an axial direction. When an overload current or a short circuit current occurs, the electrode is instantaneously opened and cut off. The contact material used in the contact portion between the fixed electrode and the movable electrode of such a vacuum valve is mainly required to have a breaking performance, a withstand voltage performance, and a low welding power performance.

  However, since these required characteristics require mutually contradictory properties for the contact material, it is difficult to manufacture the contact material from a single material, and conventionally, it is made of a material combining two or more elements. Contact material is used. As a contact material for a vacuum valve, a Cu—Cr material excellent in breaking performance and withstand voltage performance is known (for example, Patent Document 1). In addition, a contact material to which Te is added in order to reduce the welding force of the Cu—Cr material has been proposed (for example, Patent Document 2).

JP-B-54-71375 (7th line from the bottom of the right column on page 1 to 4th line from the bottom of the top left column on page 2) JP 2006-140073 A (page 2 claim 2)

  In contact materials used for vacuum valves and the like, contact surfaces are melted by Joule heat generated when current is applied for a short time or arc heat generated when current is interrupted, and then solidified to cause welding. The conventional Cu—Cr material has a large welding force, and it is necessary to provide a mechanism having a large operating force in the vacuum circuit breaker in order to remove the welded contact. For this reason, there is a demand for a material that can be easily removed even after welding or a material that is difficult to weld. It has been conventionally known that Cu—Cr material containing Te has an effect of making the base material Cu brittle and reducing the welding tear-off force. However, due to Joule heat during energization and arc heat during current interruption, Te evaporates and fouls the inside of the vacuum valve, lowering the degree of vacuum, resulting in reduced withstand voltage performance and unstable interruption performance. is there.

  On the other hand, in the conventional sintering method, when the Cr content is more than 40% by mass, the sinterability is poor and densification is difficult, and the gas content is large, so that the interruption performance is deteriorated. Further, the infiltration method has a problem that Te evaporates in the heating / infiltration process, resulting in a composition deviation of the contact material and a variation in composition.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a contact material that can be easily removed by welding. Another object of the present invention is to provide a contact material that is excellent in breaking performance and withstand voltage performance and that can be easily removed by welding and a method for manufacturing the contact material.

  A first contact material of the present invention is characterized in that a contact material containing Cr and Te in a Cu base material contains Cr—Te particles.

  A second contact material of the present invention is a contact material containing Cr and Te in a Cu base material, and includes a Cr-containing particle and a Te-containing phase formed at a grain boundary between the base material and the Cr particle. It is what.

  The third contact material of the present invention includes a Cu base material, Cr particles, Cu—Cr—Te particles in which a Te—Cu—Cr phase and a Cu—Te phase are mixed, Cr—Te particles, and the above Cu base material. And a Te-containing phase formed at a grain boundary with the Cr particles.

  In the method for producing a contact material of the present invention, Cr powder having an average particle size of 35 μm or more and 150 μm or less is in a range of 40% by mass or more and 50% by mass or less, and Te powder having an average particle size of 1 μm or more and 100 μm or less is 0 A mixture containing Cu powder with a balance of 1% by mass to 2% by mass and an average particle size of 1 μm to 75 μm as a balance is charged into a sintered mold to be 700 ° C. or higher and 1080 ° C. or lower, 30 MPa or higher and 200 MPa or lower. The pressure sintering is performed under a pressure in the range.

  Both the first and second contact materials of the present invention have the effect of being able to realize excellent welding and tearing-out properties, and have the effect of being able to be removed by welding with a low operating force. The third contact material has an effect that it can realize excellent welding / detachability while ensuring the breaking performance and withstand voltage performance, and when the contact material of the present invention is used for a vacuum valve, In addition, it is possible to ensure the breaking performance and the withstand voltage performance with a short distance between the electrodes, and to have the effect that the welding can be removed with a low operating force. The contact material manufacturing method of the present invention is effective in manufacturing such a high-performance contact material.

Embodiment 1 FIG.
1 and 2 illustrate Embodiment 1 of the present invention. FIG. 1 is a cross-sectional view of an example of a contact material of the present invention, and FIG. 2 is an example of a circuit breaker having the contact material. It is sectional drawing which shows the vacuum valve mounted in a vacuum circuit breaker.

  In FIG. 2, the shut-off chamber 9 of the vacuum valve 8 is constituted by an insulating container 10 made of an insulating material formed in a cylindrical shape, and metal lids 12a and 12b provided at both ends via sealing metal fittings 11a and 11b. The inside of the shut-off chamber 9 is vacuum-tight. The fixed electrode 15 and the movable electrode 16 are attached to the ends of the fixed electrode rod 13 and the movable electrode rod 14 in the blocking chamber 9 by brazing so as to face each other. A fixed contact 17 is attached to the contact portion of the fixed electrode 15, and a movable contact 18 is attached to the contact portion of the movable electrode 15 by brazing. A bellows 19 is attached to the movable electrode rod 14 to allow the movable electrode 16 to move in the axial direction while keeping the inside of the shut-off chamber 9 vacuum-tight. The fixed contact 17 and the movable contact 18 are made of the contact material of the present invention, and both are made of the same material.

  In addition to the flat plate electrode, the fixed electrode 15 and the movable electrode 16 include a spiral electrode with a spiral groove cut to improve the blocking performance, a control electrode with a cup-shaped contact groove, and an arc generated between the electrodes. A longitudinal magnetic field electrode that applies a magnetic field in parallel with the magnetic field is used. A metal bellows arc shield 20 is provided on the top of the bellows 19. The bellows arc shield 20 prevents metal vapor generated from the arcing region from adhering to the bellows 19. In addition, a metal insulating container arc shield 21 is provided in the shutoff chamber 9 so as to cover the fixed electrode 15 and the movable electrode 16, whereby metal vapor generated from the arcing region adheres to the inner surface of the insulating container 10. To prevent it. The opening / closing operation of the vacuum valve is performed via a movable electrode rod 14 connected to a driving mechanism (not shown).

  In FIG. 1, in a base material 1 (hereinafter referred to as Cu base material) 1 mainly composed of Cu, there are Cr particles (things with hatching of the right-down line) 2, Cu-Te phase 3 and Te-Cu-Cr phase 4. Cu—Cr—Te particles 5 and Cr—Te particles 6 (having a left-down line hatching) dispersed therein, and the base material 1 and each of the Cr particles 2 Te-containing phases 7 (shown by thick black lines) are present at each grain boundary.

  Next, the composition of the contact material of the present invention will be described. As the Cu base material 1 in each of the first to third contact materials, a small amount of inevitable impurities contained in the Cu raw material, such as Ag, Al, Fe, Si, P, O, N, and H, are included. If each is less than 0.01 mass%, you may contain them.

  In the first to third contact materials, the Cr content is preferably 40% by mass to 50% by mass. If the Cr content is less than 40% by mass, the withstand voltage performance is insufficient and 50% by mass. If it exceeds, the shut-off performance decreases. On the other hand, the Te content is preferably 0.1% by mass or more and 2% by mass or less. When the amount of Te is less than 0.1% by mass, the weldability is poor, and when it exceeds 2% by mass, the weldability is improved, but the material itself becomes brittle and is unsuitable for practical use as a contact material.

  In the first contact material of the present invention, the average diameter of the Cr—Te particles is 5 μm or less, and the average area of the Cr—Te particles in the total cross-sectional area of the contact material is the total cross-sectional area. What is 0.5 area% or less is preferable. In addition, if the average diameter is too small, there is a problem in that the weld-peelability becomes poor. On the other hand, if the average diameter is too large, there is a problem in that the variation in withstand voltage performance is large. If the total area occupied is too small with respect to the total area of the cross section, there is a problem in that the weldability is poor, whereas if it is excessive, there is a problem in that the variation in withstand voltage performance is large, The average diameter of the Cr—Te particles is 0.1 μm or more and 5 μm or less, and the average area of the Cr—Te particles is particularly preferably 0.001 area% or more and 0.5 area% or less of the total cross-sectional area.

  In the second contact material of the present invention, the Te-containing phase further preferably has an average thickness of 5 μm or less and a Te content of 90% by mass or less. On the other hand, if the average thickness is excessively large, there is a problem in that the variation in withstand voltage performance is large, and if the content is too small, the problem is that the weldability is poor. On the other hand, if the content is excessive, there is a problem in that the material itself becomes brittle. Therefore, the Te-containing phase has an average thickness of 0.1 to 5 μm and a Te content of 50 to 90% by mass. % Or less is particularly preferred.

  In the third contact material of the present invention, the Cr particles, Cu—Cr—Te particles in which Te—Cu—Cr phase and Cu—Te phase are mixed, Cr—Te particles, and the Cu base material and the above The Te-containing phase formed at the grain boundary with the Cr particles is included, but by including both the Cr-Te particles and the Te-containing phase, the above-described remarkable effects can be obtained. In that case, Cr content is the range of 40 mass% or more and 50 mass% or less, and Te content is the range of 0.1 mass% or more and 2 mass% or less. In addition, about the preferable range and reason of Cr content and Te content are as above-mentioned.

  If the average particle diameter is too small, the Cr particles have a problem in that the withstand voltage performance is lowered. On the other hand, if the average particle diameter is too large, there is a problem in that the variation in the breaking performance increases. Further, when the area ratio of the Cr particles is too small, the withstand voltage performance is insufficient, and when it is excessive, there is a problem in that the blocking performance is lowered. Therefore, the average particle diameter of Cr particles is 150 μm or less, preferably the average particle diameter is 35 μm or more and 150 μm or less. The average area of the Cr particles in the total cross-sectional area of the contact material is 55 area% or less, preferably 45 area% or more and 55 area% or less of the total cross-sectional area.

  Cu-Cr-Te particles have a problem in that if the average particle size is too small, the weld-peeling property is deteriorated. On the other hand, if the average particle size is too large, the variation in withstand voltage performance increases. There is a problem, and if the content is too small, there is a problem in that the weldability is reduced. On the other hand, if the content is excessive, there is a problem in that the variation in withstand voltage performance becomes large. Therefore, the average particle diameter of the Cu—Cr—Te particles is 100 μm or less, and preferably the average particle diameter is 1 μm or more and 100 μm or less. And the average area of the said Cu-Cr-Te particle which occupies in the total cross-sectional area of contact material is 2.5 area% or less of the said total cross-sectional area, Preferably it is 0.1 area% or more and 2.5 area% or less is there. In addition, there is no restriction | limiting in particular about the abundance ratio of the Te-Cu-Cr phase and Cu-Te phase in Cu-Cr-Te particle, It is the abundance ratio which arises with the manufacturing method of the contact material of this invention mentioned later. The area of the Cu—Te phase is about 0.3 to 1.2 with respect to the area 1 of the Te—Cu—Cr phase.

  If the average particle size is too small, Cr-Te particles have a problem in that the ability to weld and peel becomes poor. On the other hand, if the average particle size is too large, there is a problem in that the variation in withstand voltage performance increases. is there. If the total area occupied by the Cr-Te particles is too small with respect to the total area of the cross section, there is a problem in that the weldability is poor, whereas if it is excessive, the variation in withstand voltage performance becomes large. There's a problem. Therefore, the average particle diameter of the Cr—Te particles is 5 μm or less, preferably 0.1 μm or more and 5 μm or less. The average area of the Cr—Te particles is 0.5 area% or less of the total cross-sectional area, preferably 0.001 area% or more and 0.5 area% or less of the total cross-sectional area.

  The Te-containing phase has a problem in that if the average thickness is too small, the welding and peeling property is poor. On the other hand, if the average thickness is too large, there is a problem in that the variation in withstand voltage performance becomes large. If the content is too small, there is a problem in that the weldability of the weld becomes poor. On the other hand, if the content is excessive, there is a problem in that the material itself becomes brittle. Therefore, the Te-containing phase has an average thickness of 5 μm or less, preferably an average thickness of 0.1 μm or more and 5 μm or less. Moreover, Te content is 90 mass% or less, Preferably Te content is 50 to 90 mass%.

Further, when each of the above contact materials of the present invention is used as a contact material for a vacuum valve, it is used in a high vacuum. Therefore, the residual gas inside the contact material is small, and the density ratio is preferably close to the theoretical density. In particular, those having a density ratio of 90% or more that do not adversely affect performance are preferable. The density ratio is obtained from the following equation.
Density ratio = (the density of the sintered body / theoretical density of the contact material obtained from the composition analysis value) × 100

In the present invention, Cr particles, Cr-Te particles, and Cu-C contained in the contact material
Each average particle diameter and each average area of r-Te particles, Cu- contained in Cu-Cr-Te particles
The average thickness of the Te phase and the Te-Cu-Cr phase, and the average thickness of the Te-containing phase are determined by polishing the cross section of the contact material and observing the polished surface with a scanning electron microscope (SEM). Each particle diameter, area, and thickness of each phase were integrated by image processing, and calculated within the observation region to obtain each average value. Specifically, five locations where observation regions of about 200 μm square were randomly selected were observed, and average values of the particle diameter, area, and thickness of each observation region were obtained.
The content of Cr particles, Cu—Cr—Te particles, and Cr—Te particles contained in the contact material is obtained by observing the polished surface with an SEM and integrating the total area of each particle in the observation region by image processing. Determined within the observation area. Specifically, five locations where 200 μm square observation regions were randomly selected were observed, and the area ratio (area%) of each particle in each observation region was averaged.
The Te content of the Te-containing phase is the arithmetic average value obtained by conducting quantitative analysis by wavelength dispersive X-ray spectroscopy (WDS) method using an electron probe microanalyzer (EPMA) and measuring five randomly selected Te-containing phases. It calculated | required as mass%.

  In each of the first and second contact materials according to the present invention, a composition containing a necessary amount of component metals constituting each contact material is heated and fired at a temperature of 700 ° C. to 1080 ° C. and a pressure of 30 MPa to 200 MPa. It can be manufactured by tying. At that time, the average diameter and content of the Cr—Te particles in the first contact material can be adjusted by adjusting the contents of Cr and Te in the composition to be heat-sintered. The average thickness and content of the Te-containing phase can be adjusted by adjusting the content of Te in the composition to be heat-sintered. On the other hand, also in the production of the third contact material, a composition containing a necessary amount of component metals constituting the contact material is subjected to pulsed electric pressure firing under conditions of a temperature of 700 ° C. to 1080 ° C., a pressure of 30 MPa to 200 MPa. By bonding, a contact material having a structure in which a Cu-Te phase, a particle in which a Cu-Te phase and a Te-Cu-Cr phase are mixed, a Cr-Te particle is dispersed and a Te-containing phase is formed is manufactured. can do.

  In the production of the first to third contact materials according to the present invention, if the temperature during the heat sintering is low, a high pressure of 200 MPa or more is required to obtain a sintered body having a density ratio of 90% or more. However, up to 200 MPa is preferable from the viewpoint of the strength of the carbon material forming the press die. On the other hand, when sintering is performed at a temperature of 1083 ° C. or higher, which is the melting point of Cu, the molten Cu is poured into the gaps of the press die, causing a composition shift. Moreover, when sintered under a low pressure of less than 30 MPa, a sintered body having a density ratio of 90% or more cannot be obtained. Therefore, in the production of the first to third contact materials according to the present invention, a composition containing a necessary amount of component metals constituting each contact material is subjected to a temperature of 720 ° C. to 1000 ° C., a pressure of 40 MPa to 150 MPa. It is preferable to heat sinter under the following conditions, further, a temperature of 750 ° C. to 950 ° C. and a pressure of 50 MPa to 100 MPa.

  Note that the third contact material is pulsed and pressurized and sintered in addition to the above temperature and pressure. The pulsed and pressurized sintering is a well-known pulsed and pressurized sintering apparatus widely used in the field. May be used. The preferable conditions for pulse energization are, for example, an energization pulse current of 500 to 5000 A and a pulse interval time of about 3 ms. In the present invention, each of the first to third contact materials may be formed so that the contact material produced by heat-sintering has a desired shape and dimensions, but the mixed powder to be processed is formed into a desired shape. In addition, when sintered in a carbon mold having a size, the sintered product can be put to practical use directly or after being subjected to a light post-treatment. Next, the present invention will be described in more detail with reference to examples and comparative examples.

Example 1.
Cu powder having an average particle size of 35 μm and a purity of 99.9% by mass, Cr powder having an average particle size of 40 μm and a purity of 99.9% by mass, Te powder having an average particle size of 40 μm and a purity of 99.9% by mass, Was 59.5% by mass, Cr was 40% by mass, and Te was 0.1% by mass, and mixed by a V mixer. The obtained mixed powder was filled into a carbon mold having an inner diameter of 25 mm, and the carbon mold was subjected to pressure sintering in a vacuum of 6 Pa at a pressure of 50 MPa and a sintering temperature of 1050 ° C. for 60 minutes to obtain a diameter of 25 mm, a thickness of 5 mm, A Cu—Cr—Te contact material having a density ratio of 98.5% was obtained. When the Cu-Cr-Te contact material was quantitatively analyzed by the above-described method, the produced Cr-Te particles had an average particle size of 0.5 μm and a content of 0.001 area%.

Examples 2-4
In Examples 2 to 4, Cr is 40% by mass and Te is 2% by mass (Example 2), Cr is 50% by mass and Te is 0.1% by mass (Example 3). Each compound was blended so that Te would be 2% by mass (Example 4) at 50% by mass, and then mixed and sintered under the same conditions as in Example 1 to obtain the obtained Cu—Cr—Te contact material. Quantitative analysis was performed in the same manner as in Example 1. As a result, in Example 2, the average particle size of Cr—Te particles is 3 μm and the content thereof is 0.1 area%. In Example 3, the average particle size of Cr—Te particles is 1 μm and the content is 0. In Example 4, the average particle diameter of the Cr—Te particles was 5 μm, and the content thereof was 0.3 area%.

With respect to each of the Cu—Cr—Te contact materials of Examples 1 to 4, the welding trip force (hereinafter abbreviated as “welding trip force”) was measured by the following method and conditions. The welding external force of the contact material of Comparative Example 3 (with a Cu: Cr: Te ratio of 60: 40: 0) described later was 1.1 kN. On the other hand, in all of Examples 1 to 4, the welding pull-out force was in the range of 0.5 to 0.6 kN, which was as small as about 1/2 that of Comparative Example 3, and was easy to remove. .
Welding pulling force: A contact pressure of 30 kgf was applied to a vacuum valve incorporating a contact material to be tested having a diameter of 20 mm and a thickness of 5 mm, a current of 12.5 kA was applied for 2 seconds, and the welding external force was measured and evaluated by a tensile test.

Examples 5-8
Cu powder having an average particle size of 35 μm and a purity of 99.9% by mass, Cr powder having an average particle size of 40 μm and a purity of 99.9% by mass, Te powder having an average particle size of 20 μm and a purity of 99.9% by mass, 59.5% by mass, Cr 40% by mass, Te 0.1% by mass (Example 5), Te 0.5% by mass (Example 6), Te 1% by mass (Example 7), Each of them was blended so that Te was 2% by mass (Example 8), and mixed with a V mixer.

  Each obtained mixed powder was filled in a carbon mold having an inner diameter of 25 mm, and the carbon mold was subjected to pressure sintering in a vacuum at a pressure of 50 MPa and a sintering temperature of 800 ° C. for 20 minutes to obtain a diameter of 25 mm, a thickness of 5 mm, and a density. Four Cu—Cr—Te contact materials with a ratio of 98.5% were obtained. When each Cu—Cr—Te contact material was analyzed by the above method, the Te-containing phase in Example 5 thus produced had an average thickness of 0.1 μm, and its Te content was 85% by mass. The Te-containing phase in Example 1 has an average thickness of 0.4 μm, the Te content is 70% by mass, the Te-containing phase in Example 7 has an average thickness of 1 μm, and the Te content is 60% by mass. The Te-containing phase in Example 8 had an average thickness of 3 μm, and the Te content was 55% by mass.

  When each of the Cu-Cr-Te contact materials of Examples 5 to 8 was measured for welding external force by the above-mentioned method and conditions, the properties of the contact material of Comparative Example 3 were set as 1, and the relative comparison was made. In all of Nos. 5 to 8, the welding pull-out force was in the range of 0.5 to 0.6 kN, which was as small as about 1/2 of that of Comparative Example 3, and was easy to remove.

Example 9
A Cu powder having an average particle size of 35 μm and a purity of 99.9%, a Cr powder having an average particle size of 80 μm and a purity of 99.9% by mass, and a Te powder having an average particle size of 40 μm and a purity of 99.9% by mass, They were blended so that 59.5% by mass, Cr was 40.0% by mass, and Te was 0.5% by mass, and mixed by a V mixer. The obtained mixed powder is filled into a carbon mold having an inner diameter of 25 mm, and the carbon mold is subjected to pulse energization under the conditions of a sintering pressure of 50 MPa, a sintering temperature of 800 ° C. for 20 minutes, a peak current of 1200 A, and a current pulse interval of 3 ms. Pressure sintering was performed to obtain a Cu—Cr—Te contact material having a diameter of 25 mm, a thickness of 5 mm, and a density ratio of 99%.

  The contact material was cut using a wet cutting machine, and the polished surface of the cross section was enlarged by SEM and EPMA for observation / analysis. As in FIG. 2, in the Cu base material, Cr particles, Cu -Te phase and Te-Cu-Cr phase co-existing Cu-Cr-Te particles, Cr-Te particles exist in a dispersed state, and further exist at the grain boundary between the base material 1 and Cr particles. A Te-containing phase was observed. The same applies to the subsequent embodiments. Next, the size and content of each particle and the average thickness and average Te content of the Te-containing phase 7 were quantitatively analyzed by the above-described image processing method (this is the same in the subsequent examples). However, the Cr particles have an average particle size of 80 μm and a content of 45 area%, and the Cu—Cr—Te particles have an average particle diameter of 40 μm and a content of 0.5 area%, and the Cr—Te particles The average particle diameter is 1 μm, the content is 0.002 area%, the Te-containing phase has an average thickness of 0.5 μm, the Te content is 70% by mass, the density ratio is 99%, The breaking performance was acceptable, the withstand voltage performance was 1.0, and the welding pulling external force was 0.5 to 0.6 kN.

In the present invention, the breaking performance and withstand voltage performance were measured and judged by the following methods and conditions, respectively. The measurement and determination are the same for the following examples and comparative examples.
Breaking performance: A contact material to be tested having a diameter of 30 mm and a thickness of 5 mm was incorporated in a vacuum valve, and a short-circuit breaking test was performed with a distance between contacts of 4.5 mm and a breaking current of 12.5 kA. The case was rejected.
Withstand voltage performance: Contact material of a test sample having a diameter of 20 mm and a thickness of 5 mm is incorporated in a vacuum valve, an impulse voltage test is performed at a distance between contacts of 2 mm, and a contact material of Comparative Example 3 described later comprising 60 mass% Cu and 40 mass% Cr The withstand voltage characteristics were expressed as relative comparison values.

Example 10
It differs from Example 9 only in that Cu is 59.0% by mass and Te is 1.0% by mass, and the other is the same. A Cr—Te contact material was obtained. In the contact material, the Cr particles have an average particle diameter of 80 μm and the content is 45 area%, and the Cu—Cr—Te particles have an average particle diameter of 40 μm and a content of 1.3 area%. The Te particles have an average particle diameter of 3 μm and a content of 0.07 area%, the Te-containing phase has an average thickness of 3 μm, a Te content of 70% by mass, and a density ratio of 98%. The breaking performance was acceptable, the withstand voltage performance was 1.1, and the welding pulling external force was 0.5 to 0.6 kN.

Example 11
It differs from Example 9 only in that Cu is 58.0% by mass and Te is 2.0% by mass, and the others are the same. A Cr—Te contact material was obtained. In the point material, the Cr particles have an average particle diameter of 80 μm and the content is 45 area%, and the Cu—Cr—Te particles have an average particle diameter of 40 μm and a content of 2.6 area%. Te particles have an average particle size of 3 μm and a content of 0.1 area%, a Te-containing phase has an average thickness of 3 μm, a Te content of 70% by mass, a density ratio of 98%, The breaking performance was acceptable, the withstand voltage performance was 1.1, and the welding pulling external force was 0.5 to 0.6 kN.

Example 12
Example 9 differs from Example 9 only in that Cu is 54.5% by mass, Cr is 45% by mass, and Te is 0.5% by mass. Other than that, the diameter is 25 mm, the thickness is 5 mm, and the density ratio is the same. 98% Cu-Cr-Te contact material was obtained. In the contact material, Cr particles have an average particle diameter of 80 μm and a content of 50 area%, Cu—Cr—Te particles have an average particle diameter of 40 μm, a content of 0.6 area%, Cr— The Te particles have an average particle size of 1 μm and a content of 0.01 area%, the Te-containing phase has an average thickness of 0.5 μm, a Te content of 70% by mass, and a density ratio of 98. %, The breaking performance was acceptable, the withstand voltage performance was 1.1, and the welding pulling external force was 0.5 to 0.6 kN.

Example 13
It differs from Example 9 in that Cu is 49.9% by mass, Cr is 50.0% by mass, Te is 0.1% by mass, the sintering temperature is 900 ° C., and the sintering pressure is 80 MPa. Obtained a Cu—Cr—Te contact material having a diameter of 25 mm and a thickness of 5 mm under the same production conditions. In the contact material, Cr particles have an average particle size of 80 μm and a content of 55 area%, Cu—Cr—Te particles have an average particle diameter of 40 μm, a content of 0.1 area%, Cr— The Te particles have an average particle size of 1 μm and a content of 0.01 area%, the Te-containing phase has an average thickness of 0.1 μm, a Te content of 60% by mass, and a density ratio of 98. %, The breaking performance was acceptable, the withstand voltage performance was 1.3, and the welding pulling external force was 0.5 to 0.6 kN.

Example 14
The difference from Example 9 is that Cu is 48.0% by mass, Cr is 50.0% by mass, Te is 2.0% by mass, the sintering temperature is 900 ° C., and the sintering pressure is 80 MPa. Obtained a Cu—Cr—Te contact material having a diameter of 25 mm, a thickness of 5 mm, and a density ratio of 98% under the same production conditions. In the contact material, Cr particles have an average particle diameter of 80 μm and a content of 55 area%, Cu—Cr—Te particles have an average particle diameter of 40 μm, a content of 2.5 area%, Cr— Te particles have an average particle size of 5 μm and a content of 0.2 area%, a Te-containing phase has an average thickness of 3 μm, a Te content of 60% by mass, a density ratio of 98%, The breaking performance was acceptable, the withstand voltage performance was 1.1, and the welding pulling external force was 0.5 to 0.6 kN.

Example 15.
The difference from Example 9 is that Cu is 59.5% by mass, Cr is 40.0% by mass, Te is 0.5% by mass, the sintering temperature is 950 ° C., and the sintering pressure is 30 MPa. Obtained a Cu—Cr—Te contact material having a diameter of 25 mm and a thickness of 5 mm under the same production conditions. In the contact material, Cr particles have an average particle size of 80 μm and a content of 45 area%, and Cu—Cr—Te particles have an average particle diameter of 40 μm and a content of 0.7 area%. The Te particles have an average particle size of 0.7 μm and a content of 0.002 area%, the Te-containing phase has an average thickness of 0.8 μm, a Te content of 55% by mass, and a density ratio Was 98%, the breaking performance was acceptable, the withstand voltage performance was 0.9, and the welding external force was 0.5 to 0.6 kN.

Example 16
It differs from Example 9 in that Cu is 59.5% by mass, Cr is 40.0% by mass, Te is 0.5% by mass, the sintering temperature is 700 ° C., and the sintering pressure is 70 MPa. Obtained a Cu—Cr—Te contact material having a diameter of 25 mm and a thickness of 5 mm under the same production conditions. In the contact material, Cr particles have an average particle size of 80 μm and a content of 45 area%, and Cu—Cr—Te particles have an average particle diameter of 40 μm and a content of 0.7 area%. The Te particles have an average particle size of 0.2 μm and a content of 0.001 area%, the Te-containing phase has an average thickness of 0.5 μm, a Te content of 85% by mass, and a density ratio Was 98%, the breaking performance was acceptable, the withstand voltage performance was 0.9, and the welding external force was 0.5 to 0.6 kN.

  Here, an example in which the Cu—Cr—Te contact material of Example 10 is selected as a representative and its cross section is observed with an electron microscope will be described. Te in the material is sintered by the manufacturing method of the present invention, and Te is Cu-Cr-Te particles, Cu-Te phases, Cr-Te particles in which Te-Cu-Cr phase and Cu-Te phase are mixed. Furthermore, it is dispersed in the Te-containing phase present at the grain boundary between the Cu base material and the Cr particles, resulting in a structure in which the unique alloy phase of the present invention is dispersed. The Cu—Cr—Te particles were larger than 0 and 100 μm or less, and the Cr—Te particles were larger than 0 and 5 μm or less. There was a discontinuous Te-containing phase at the grain boundary between the Cr particles and the Cu base material, and the thickness was greater than 0 and 5 μm or less.

  The particle size of the Cu-Cr-Te particles changes depending on the Te particle size used as the starting material, while the single Cu-Te phase, Cr-Te particles, and Te-containing phase are the starting materials. The particle size is smaller than the Te particle size used in the present invention, and becomes a fine size independent of the Te particle size, Te blending amount, and sintering conditions in the present invention. Therefore, it is considered that a Cr-Te particle having a particle size greater than 0 and not more than 5 μm, and a discontinuous Te-containing phase between a Cr particle having a thickness greater than 0 and not more than 5 μm and a Cu base material are stable and preferable sizes.

Further, as a result of quantitative analysis of the mixed Cu—Te phase and Te—Cu—Cr phase by the WDS method using EPMA, the Cu—Te phase is Cu 51 mass% to 54 mass%, Te is 46 mass% to 49 mass%. The chemical structure was less than mass% and was close to Cu ₂ Te in terms of chemical structure. In the Te—Cu—Cr phase, Te was 63 mass% to 67 mass%, Cu was 23 mass% to 25 mass%, and Cr was 8 mass% to 12 mass%.

On the other hand, the fine Cr-Te particles and the Te-containing phase formed at the grain boundary between the Cu base material and the Cr particles were confirmed by surface analysis by EPMA and quantitative analysis by the WDS method. It seems to be composed of Cr ₃ Te ₄ , Cr ₂ Te ₃ , CrTe _3, etc., and the Te-containing phase is thought to be composed of Te—Cu—Cr alloy phase, Cu—Te alloy phase, etc. It was. Further, as a result of observation and analysis by SEM and EPMA, the particle diameter of Cr particles was mainly 35 μm or more and 150 μm or less, but a minimum of 0.5 μm Cr particles was confirmed. The diameter of the mixed phase of the Te—Cu—Cr phase and the Cu—Te phase was 75 μm or less, and a mixed phase having a minimum of 1 μm was confirmed. The Cr—Te phase was 0.5 μm or more and 5 μm or less. Although not shown in FIG. 1, it was also confirmed that a Cu—Te phase having a diameter of 1 μm or more and 20 μm or less was present alone.

Comparative Example 1
Example 9 differs from Example 9 in that Cu is 69.0% by mass, Cr is 30.0% by mass, and Te is 1.0% by mass. Other than that, the diameter is 25 mm and the thickness is 5 mm under the same manufacturing conditions. A Cu—Cr—Te contact material was obtained. In the contact material, the Cr particles have an average particle diameter of 80 μm and the content is 35 area%, and the Cu—Cr—Te particles have an average particle diameter of 40 μm and a content of 1.3 area%. Te particles have an average particle size of 1 μm and a content of 0.02 area%, a Te-containing phase has an average thickness of 1 μm, a Te content of 70% by mass, a density ratio of 99%, The interruption performance was negative, the withstand voltage performance was 0.9, and the welding external force was 0.4 to 0.6 kN.

Comparative Example 2
Example 9 differs from Example 9 in that Cu is 39.0% by mass, Cr is 60.0% by mass, Te is 1.0% by mass, the sintering temperature is 900 ° C., and the sintering pressure is 70 MPa. Obtained a Cu—Cr—Te contact material having a diameter of 25 mm and a thickness of 5 mm under the same production conditions. In the contact material, Cr particles have an average particle size of 80 μm and a content of 65 area%, and Cu—Cr—Te particles have an average particle diameter of 40 μm and a content of 1.2 area%. The Te particles have an average particle diameter of 1.2 μm and a content of 0.05 area%, the Te-containing phase has an average thickness of 1 μm, a Te content of 60% by mass, and a density ratio of 98. %, The breaking performance was negative, the withstand voltage performance was 1.2, and the welding pulling external force was 0.4 to 0.6 kN.

Comparative Example 3
Example 9 differs from Example 9 in that Cu is 60.0% by mass, Cr is 40.0% by mass, and Te is 0% by mass. Other than that, the diameter is 25 mm and the thickness is 5 mm under the same manufacturing conditions. A Cu-Cr contact material was obtained. In the contact material, Cr particles have an average particle size of 80 μm and a content of 45 area%, Cu—Cr—Te particles have a content of 0 area%, and Cr—Te particles have a content of 0 area. The Te-containing phase has a Te content of 0% by mass, a density ratio of 98%, an interrupting performance is possible, a withstand voltage performance is 1, and a welding pulling external force is 1.1 kN. It was.

Comparative Example 4
Example 9 differs from Example 9 in that Cu is 57.0% by mass, Cr is 40.0% by mass, and Te is 3.0% by mass. Other than that, the diameter is 25 mm and the thickness is 5 mm under the same manufacturing conditions. A Cu—Cr—Te contact material was obtained. In the contact material, the Cr particles have an average particle diameter of 80 μm and the content is 45 area%, the Cu—Cr—Te particles have a content of 3.9 area%, and the Cr—Te particles have a content of 3.9 area%, Te-containing phase has a Te content of 65% by mass, a density ratio of 98%, interrupting performance is negative, withstand voltage performance is 0.7, welding pulling external force Was 0.3 to 0.6 kN.

Comparative Example 5
Example 9 differs from Example 9 in that Cu is 59.0% by mass, Cr is 40.0% by mass, and Te is 1.0% by mass. A 5 mm Cu—Cr—Te contact material was obtained. In the contact material, Cr particles have an average particle diameter of 170 μm and a content of 45 area%, Cu—Cr—Te particles have a content of 1.3 area%, and Cr—Te particles have a content of It is 0.05 area%, and the Te-containing phase has a Te content of 65% by mass, a density ratio of 98%, a non-breaking performance, and a withstand voltage performance of 0.7 to 0.9. The welding pulling external force was 0.4 to 0.6 kN.

Comparative Example 6
Example 9 differs from Example 9 in that Cu is 59.0% by mass, Cr is 40.0% by mass, and Te is 1.0% by mass. Other than that, the diameter is 25 mm and the thickness is 5 mm under the same manufacturing conditions. A Cu—Cr—Te contact material was obtained. In the contact material, Cr particles have an average particle diameter of 10 μm and a content of 45 area%, Cu—Cr—Te particles have a content of 1.3 area%, and Cr—Te particles have a content of It is 0.05 area%, and the Te-containing phase has a Te content of 65% by mass, a density ratio of 98%, an interruption performance is possible, and a withstand voltage performance is 0.7 to 0.9. The welding pulling external force was 0.4 to 0.6 kN.

Comparative Example 7
Example 9 differs from Example 9 in that Cu is 59.0% by mass, Cr is 40.0% by mass, and Te is 1.0% by mass. Other than that, the diameter is 25 mm and the thickness is 5 mm under the same manufacturing conditions. A Cu—Cr—Te contact material was obtained. In the contact material, Cr particles have an average particle size of 80 μm and a content of 45 area%, and Cu—Cr—Te particles have an average particle diameter of 120 μm and a content of 1.3 area%, Cr— The Te particles have a content of 0.05 area%, the Te-containing phase has a Te content of 65% by mass, a density ratio of 98%, an interruption performance, and a withstand voltage performance of 0.8%. The welding pulling external force was 0.5 to 0.9 kN.

Comparative Example 8
The difference from Example 9 is that Cu is 59.0% by mass, Cr is 40.0% by mass, Te is 1.0% by mass, the sintering temperature is 900 ° C., and the sintering pressure is 25 MPa. A Cu—Cr—Te contact material having a diameter of 25 mm and a thickness of 5 mm was obtained under the same manufacturing conditions. In the contact material, Cr particles have an average particle size of 80 μm and a content of 45 area%, Cu—Cr—Te particles have a content of 1.3 area%, and Cr—Te particles have a content of The Te-containing phase has a Te content of 60% by mass, a density ratio of 89%, an interrupting performance of no, a withstand voltage performance of 0.8, and a welding pulling external force of 0. .4 to 0.6 kN.

Comparative Example 9
The difference from Example 9 is that Cu is 59.0% by mass, Cr is 40.0% by mass, Te is 1.0% by mass, the sintering temperature is 600 ° C., and the sintering pressure is 80 MPa. A Cu—Cr—Te contact material having a diameter of 25 mm and a thickness of 5 mm was obtained under the same manufacturing conditions. In the contact material, Cr particles have an average particle size of 80 μm and a content of 45 area%, Cu—Cr—Te particles have a content of 0 area%, and Cr—Te particles have a content of 0 area. The Te-containing phase has a Te content of 0 area%, a density ratio of 95%, a blocking performance of no, a withstand voltage performance of 0.9, and a welding pulling external force of 0.4. -0.6 kN.

Comparative Example 10
Cu is 59.0% by mass, Cr is 40.0% by mass, Te is 1.0% by mass, the sintering temperature is 1060 ° C., and the sintering pressure is 0 MPa. A Cu—Cr—Te contact material having a thickness of 5 mm was obtained. In the contact material, the Cr particles have an average particle size of 80 μm and the content is 45 area%, the Cu—Cr—Te particles have a content of 1 area%, and the Cr—Te particles have a content of 0 area. The Te-containing phase has a Te content of 0% by mass, a density ratio of 89%, an interrupting performance of no, a withstand voltage performance of 0.9, and a welding pulling external force of 0.4. -0.6 kN.

  When the above Examples 9-16 and Comparative Examples 1-10 are compared, Comparative Examples 1-6 are composition, the presence or absence of each alloy phase, Cr particle diameter, and each particle diameter of Cu-Cr-Te particle | grains. At least one does not satisfy the conditions of the contact material of the present invention. In Comparative Examples 7 to 9, at least one of pressure, sintering temperature, and sintering method does not satisfy the manufacturing conditions for the contact material of the present invention. The contact materials of Comparative Example 1 and Comparative Example 2 were in the case where the Cr amount did not satisfy the conditions of the contact material of the present invention, and although the pressure resistance performance and the welding detachability were obtained, the interruption performance was not possible. On the other hand, it has become clear that the contact materials of the present invention shown in Examples 9 to 14 have the effect of obtaining high breaking performance while maintaining the pressure resistance performance and the welding pulling external force. In addition, although the interruption | blocking performance of Example 14-Example 16 was falling a little compared with those of Example 9-Example 14, it was the range without a problem practically.

  Incidentally, as a result of observing and analyzing the cross-sectional structure of the contact material of Example 10 with SEM and EPMA, the particle size of the Cr particles is mostly from 38 μm to 150 μm, but the minimum is 0.5 μm Cr. Particles were confirmed. It was confirmed that the diameter of the Cu—Cr—Te particles in which the Te—Cu—Cr phase and the Cu—Te phase coexist is 75 μm or less and the minimum is 1 μm. The Cr—Te phase was 1 μm or more and 5 μm or less. Further, although not shown in FIG. 1, it was also confirmed that a Cu—Te phase having a diameter of 1 μm or more and 20 μm or less was present alone.

  On the other hand, Comparative Example 3 and Comparative Example 4 are a case where Te is not contained and a case where Te is 2.5 mass% and does not satisfy the Te amount condition of the present invention. In the case where Te was not contained, welding occurred, and the characteristics of Examples 1 to 8 were examined by setting the characteristics when removed at this time to 1. When the amount of Te exceeds 2% by mass, the resistance to withstand voltage is deteriorated but the breaking performance is not possible, although the weld resistance is obtained. In addition, the contact material itself became brittle and the workability decreased. In Comparative Example 5, the Cr particle size is 170 μm, which exceeds the upper limit of 150 μm of the Cr particle size of the present invention. When particles having a Cr particle size exceeding 150 μm were mixed, Cr particles were not uniformly dispersed in the Cu base material, resulting in variations in the blocking performance, and the blocking performance was not possible. In Comparative Example 6, the withstand voltage performance varied in the case of 35 μm or less which is the lower limit value of the Cr particle diameter of the present invention. Compared to Comparative Example 4 and Comparative Example 5, in Examples 9 to 16, good breaking performance and voltage resistance performance can be obtained while maintaining weldability, and the Cr particle size is from 35 μm to 150 μm. It turns out that it is a preferable range.

  Comparative Example 7 is a case where Te having a Te particle diameter of 120 μm was used and exceeded the upper limit of 100 μm of the Te particle diameter of the present invention. As a result, the particle size of the mixed phase of the Te—Cu—Cr phase and the Cu—Te phase exceeded 100 μm, and the dispersion became uneven, resulting in variations in the welding trip force. The comparative example 8 is a case where the pressure of manufacturing conditions is 25 MPa and is less than 30 MPa which is the lower limit value of the pressure of the present invention. The density ratio was as low as 89%, and the interruption performance was lowered, and the interruption performance was not possible. However, in order to improve the density ratio, the contacts of the present invention may be obtained by performing recompression and re-sintering, which are known methods. For example, the sintered body obtained in Comparative Example 8 may be recompressed at a pressure of 30 MPa or higher and then re-sintered at a temperature of 700 ° C. or higher and 1080 ° C. or lower.

  The comparative example 9 is a case where the sintering temperature of manufacturing conditions is 600 degreeC, and is less than 700 degreeC which is the minimum value of the sintering temperature of this invention. When manufactured under these conditions, Cr particles, a Cu—Te phase and a Te—Cu—Cr phase are formed and dispersed in the base material mainly composed of Cu. A Te-containing phase cannot be formed at the grain boundaries between Te particles, and further Cr particles and the base material, and the density ratio is also lower than in Examples 9-16. As a result, the withstand voltage performance was lowered and the interruption performance was not possible. Comparative Example 10 is a case where a green compact of 59% by mass of Cu, 40% by mass of Cr, and 1% by mass of Te is solid-phase sintered below the melting point of Cu and does not include the manufacturing process of the present invention. It is. In the base material mainly composed of Cu, Cr particles and particles in which a Te—Cu—Cr phase and a Cu—Te phase are mixed are formed and dispersed, but the Cu—Te phase, Cr—Te particles, and further Cr particles. A Te-containing phase was not formed at the grain boundary between the base material and the base material. Also, the density ratio is low compared to Examples 9-16. As a result, the withstand voltage performance was lowered and the interruption performance was not possible.

  The present invention has been described in detail with reference to the embodiments and examples. However, the present invention is not limited to these embodiments and examples, and various modifications may be made in accordance with the problems of the present invention and the spirit of the solution. Is also included.

  The present invention is likely to be used as a contact material for a vacuum circuit breaker, for example.

It is sectional drawing of an example of the contact material of this invention. It is sectional drawing which shows the vacuum valve which has the contact material of this invention.

Explanation of symbols

1: Cu base material, 2: Cr particles, 3: Cu—Te phase, 4: Te—Cu—Cr phase,
5: Cu—Cr—Te particles, 6: Cr—Te particles, 7: Te-containing phase, 8: Vacuum valve,
9: shut-off chamber, 10: insulating container, 11a: sealing metal fitting, 11b: sealing metal fitting, 12a: metal lid,
12b: metal lid, 13: fixed electrode rod, 14: movable electrode rod, 15: fixed electrode,
16: movable electrode, 17: fixed contact, 18: movable contact, 19: bellows,
20: Arc shield for bellows, 21: Arc shield for insulating container.

Claims (8)

  A contact material containing Cr and Te in a Cu base material, wherein the contact material contains Cr-Te particles.   The Cr content is in the range of 40% by mass or more and 50% by mass or less, the Te content is in the range of 0.1% by mass or more and 2% by mass or less, the average particle size of the Cr—Te particles is 5 μm or less, and The contact material according to claim 1, wherein an average area of the Cr-Te particles occupying in a total cross-sectional area of the contact material is 0.5 area% or less of the total cross-sectional area.   A contact material comprising Cr and Te in a Cu base material, comprising a Cr particle, and a Te-containing phase formed at a grain boundary between the base material and the Cr particle.   The Cr content is in the range of 40% by mass to 50% by mass, the Te content is in the range of 0.1% by mass to 2% by mass, the Te-containing phase has an average thickness of 5 μm or less, Te Content is 90 mass% or less, Contact material of Claim 3 characterized by the above-mentioned.   Formed at the grain boundary between the Cu base material and the Cr particle, and the Cu base material and the Cr particle, in which the Cr base material contains a mixture of Cr particles, Te—Cu—Cr phase and Cu—Te phase. A contact material comprising a modified Te-containing phase.   The Cr content is in the range of 40% by mass or more and 50% by mass or less, the Te content is in the range of 0.1% by mass or more and 2% by mass or less, the average particle size of the Cr particles is 150 μm or less, and the contact material is completely disconnected. The average area of the Cr particles occupying the area is 0.5 area% or less of the total cross-sectional area, the average particle diameter of the Cu—Cr—Te particles is 100 μm or less, and occupies the total cross-sectional area of the contact material. The average area of the Cu—Cr—Te particles is 2.5 area% or less of the total cross-sectional area, the average particle size of the Cr—Te particles is 5 μm or less, and the Cr occupies the total cross-sectional area of the contact material. -The average area of Te particles is 0.5 area% or less of the total cross-sectional area, the Te-containing phase has an average thickness of 5 µm or less, and a Te content of 90 mass% or less. The contact material according to claim 5.   Cr powder having an average particle size of 35 μm or more and 150 μm or less in the range of 40% by mass or more and 50% by mass or less, Te powder having an average particle size in the range of 1 μm or more and 100 μm or less of 0.1% by mass or more and 2% by mass or less , And the mixture having the average particle size of Cu powder in the range of 1 μm or more and 75 μm or less as a balance is filled in a sintering mold and subjected to pressure sintering under a pressure in the range of 700 ° C. to 1080 ° C. and 30 MPa to 200 MPa. A method for manufacturing a contact material.   The method for producing a contact material according to claim 7, wherein the pressure sintering is pulsed current pressure sintering.

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