CN102362326B - Electrical contact material - Google Patents
Electrical contact material Download PDFInfo
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- CN102362326B CN102362326B CN201080013341.2A CN201080013341A CN102362326B CN 102362326 B CN102362326 B CN 102362326B CN 201080013341 A CN201080013341 A CN 201080013341A CN 102362326 B CN102362326 B CN 102362326B
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- electric contact
- contact material
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- silver
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/02—Contacts characterised by the material thereof
- H01H1/021—Composite material
- H01H1/023—Composite material having a noble metal as the basic material
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/04—Making non-ferrous alloys by powder metallurgy
- C22C1/05—Mixtures of metal powder with non-metallic powder
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/10—Alloys containing non-metals
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C5/00—Alloys based on noble metals
- C22C5/06—Alloys based on silver
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/02—Contacts characterised by the material thereof
- H01H1/021—Composite material
- H01H1/023—Composite material having a noble metal as the basic material
- H01H1/0233—Composite material having a noble metal as the basic material and containing carbides
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/02—Contacts characterised by the material thereof
- H01H1/021—Composite material
- H01H1/027—Composite material containing carbon particles or fibres
Abstract
Disclosed is an electrical contact material which can be reduced in the wear-out rate after a cut-off test that is carried out by an overload test or short-circuit test for breakers and the like. Also disclosed is an electrical contact material which can be prevented from being welded after a cut-off test that is carried out by a short-circuit test for breakers and the like. An electrical contact material (31) according to one embodiment of the present invention contains not less than 4% by mass but not more than 7% by mass of graphite with the balance made up of silver and unavoidable impurities, and has a deflection of not less than 0.5 mm, a Vickers hardness of not less than 55, and an oxygen content of not more than 100 ppm. Preferably, the electrical contact material (31) additionally contains tungsten carbide. The tungsten carbide is preferably contained in an amount of not less than 2% by mass but not more than 4% by mass, and has an average particle diameter of not less than 40 nm but not more than 3 [mu]m. An electrical contact material (31) according to another embodiment of the present invention contains not less than 0.5% by mass but not more than 2% by mass of graphite with the balance made up of silver and unavoidable impurities, and has a deflection of not less than 0.8 mm, a Vickers hardness of not less than 40, and an oxygen content of not more than 100 ppm.
Description
Technical field
Present invention relates in general to electric contact material, particularly for the electric contact material of the interceptor (isolating switch) that formed by silver-graphitic (Ag-Gr) based material etc.
Background technology
The electric contact material all the time formed by silver-graphitic based material is known.
Such as, in patent documentation Japanese Unexamined Patent Publication 8-239724 publication (hereinafter referred to as patent documentation 1), disclose the material for electrical contact formed by the silver containing 0.05 ~ 7 % by weight carbon, silver alloys or silver composite material.This is used in the material of electrical contact, and carbon is less than the carbon black of 150nm form with average primary particle diameter is added in the powder of silver, silver alloys or silver composite material, and by extruding, this mixture is compressed by isostatic cool pressing and sinters.
Disclose in patent documentation Japanese Patent No. 3138965 publication (hereinafter referred to as patent documentation 2) by silver, the alloy of argentiferous or the matrix material of argentiferous and 0.5 ~ 10 % by weight the matrix material for electrical contact that formed of carbon.This is used in the matrix material of electrical contact, carries out powder metallurgy processed by with the carbon dust of carbon fibers together with pulverous metal composites, to form such material: the mean length of carbon fiber is more than 2 times of the mean diameter of carbon dust particle.
In patent documentation Japanese Unexamined Patent Publication 2007-169701 publication (hereinafter referred to as patent documentation 3), disclose such electrical contact material, it is the shaping sintered compact of the composite powder taking silver powder as main component.This electrical contact material is manufactured by following operation: be mixed into micropowder in the inner dispersion of silver powder, and the main material and the micropowder that take silver powder as main component are mixed into the operation of mixed powder by mechanical alloying; This composite powder is configured as the operation of molding; And to the operation that this molding sinters.
Prior art document
Patent documentation
Patent documentation 1: Japanese Unexamined Patent Publication 8-239724 publication
Patent documentation 2: Japanese Patent No. 3138965 publication
Patent documentation 3: Japanese Unexamined Patent Publication 2007-169701 publication
Summary of the invention
Invent problem to be solved
When utilizing the electric contact material formed by silver-graphitic based material to form current breaker, the electroconductibility of this electric contact material is high, is therefore difficult to heating, almost not by the harm caused of generating heat.But, in the short circuit blocking test utilizing the current breaker of electric contact material formed by silver-graphitic based material, owing to putting on thermal shocking on electric contact material or mechanical shock, there is the problem that the rate of consumption of the electric contact material after test is so greatly.
Therefore, the object of this invention is to provide a kind of electric contact material, it can be reduced in the rate of consumption after utilizing the overload trial of current breaker etc. or the blocking test of short-circuit test.
In addition, another object of the present invention is to provide a kind of electric contact material, and it can prevent the deposition after the blocking test of the short-circuit test utilizing current breaker etc.
The means of dealing with problems
The reason of the present inventor to the rate of consumption of electric contact material after the short circuit blocking test of current breaker utilizing the electric contact material formed by silver-graphitic based material has carried out various research.
First, because load current value to be breaking current in the big current isolating switch of about 100 ~ 3200A large, so flow through relatively large electric current being loaded in the electric contact material in this current breaker.Therefore, concerning this electric contact material, more high heat resistance is required compared with electroconductibility.In order to meet this requirement, the electric contact material relatively low for the content of the silver in silver-graphitic based material, the content of graphite is relatively high is used for big current isolating switch.Specifically, the electric contact material for big current current breaker contains and is more than or equal to 4 quality % and the graphite that is less than or equal to 7 quality %, and remainder is formed by silver and inevitable impurity.
In the blocking test of big current current breaker, carry out consuming from the contact after the short-circuit test being opened to closing movement becoming very important with large breaking current.It is believed that, in this short-circuit test, the reason of electric contact material consumption is instantaneously under the condition that breaking current is large to carry out from being opened to closing movement, therefore, put on heat energy on electric contact material when first short circuit blocking test or mechanical shock large.
But, the reason of the present inventor to electric contact material consumption after the short-circuit test of big current current breaker is attentively studied repeatedly, found that, the consumption after short-circuit test can be reduced by doing like this: relatively increase to more than certain particular value to the hardness under the normal temperature of major general's electric contact material; In addition, amount of flexibility is increased to more than certain particular value relatively; Oxygen level is suppressed below particular value; Further, electric contact material is formed by flowing through big current in indeformable mode under febrile state (under high temperature).Based on this discovery, electric contact material according to an aspect of the present invention, possesses following feature.
Electric contact material according to an aspect of the present invention, be less than or equal to the graphite of 7 quality % containing being more than or equal to 4 quality %, remainder contains silver and inevitable impurity, and amount of deflection is more than or equal to 0.5mm, Vickers' hardness is more than or equal to 55, and oxygen level is less than or equal to 100ppm.
In electric contact material according to an aspect of the present invention, preferred bending strength is more than or equal to 210MPa.
In addition, in electric contact material according to an aspect of the present invention, preferably, the median size of graphite is more than or equal to 40nm and is less than or equal to 8 μm.
In addition, in order to prevent the deposition utilized after the blocking test of short-circuit test, electric contact material according to an aspect of the present invention, preferably also containing wolfram varbide.
In this case, preferably, the median size of wolfram varbide be more than or equal to 40nm and be less than or equal to 3 μm, the content of wolfram varbide is more than or equal to 2 quality % and is less than or equal to 4 quality %.It is further preferred that the median size of wolfram varbide is more than or equal to 40nm and is less than or equal to 150nm.
Next, because the breaking current of the small area analysis current breaker of load current value about 1 ~ 60A is little, so flow through relatively little electric current being loaded in the electric contact material in this current breaker.Therefore, concerning this electric contact material, more high conductivity is required compared with thermotolerance.In order to meet this requirement, the relatively low electric contact material of content that the is silver content in silver-graphitic based material is relatively high, graphite is used for small area analysis current breaker.Specifically, the electric contact material for small area analysis current breaker contains and is more than or equal to 0.5 quality % and the graphite that is less than or equal to 2 quality %, and remainder is formed by silver and inevitable impurity.
In the blocking test of small area analysis current breaker, repeatedly repeatedly carry out consuming from the contact after the overload trial of the action being opened to closedown becoming very important with little breaking current.But, think all the time, in the blocking test of small area analysis current breaker, under the condition that breaking current is little, the instantaneous action carried out from being opened to closedown, therefore, the mechanical shock put on electric contact material when overload trial is once little, and the damage of the electric contact material that mechanical shock causes is little.
But, the reason of the present inventor to electric contact material consumption after the overload trial of small area analysis current breaker is attentively studied repeatedly, found that, the consumption after overload trial can be reduced by doing like this: the amount of flexibility to major general's electric contact material increases to more than certain particular value relatively; In addition, the hardness under the normal temperature of electric contact material is increased to more than certain particular value relatively; Oxygen level is suppressed below particular value; Further, electric contact material is formed in the mode that can tolerate repetitious mechanical shock.Based on this discovery, electric contact material according to a further aspect in the invention, possesses following feature.
Electric contact material according to a further aspect in the invention, be less than or equal to the graphite of 2 quality % containing being more than or equal to 0.5 quality %, remainder contains silver and inevitable impurity, and amount of deflection is more than or equal to 0.8mm, Vickers' hardness is more than or equal to 40, and oxygen level is less than or equal to 100ppm.
Electric contact material according to a further aspect in the invention, preferred bending strength is more than or equal to 120MPa.
In addition, electric contact material according to a further aspect in the invention, the median size of preferred graphite is more than or equal to 40nm and is less than or equal to 8 μm.
Invention effect
As mentioned above, according to the present invention, the electric contact material be loaded in big current current breaker can reduce the rate of consumption after short-circuit test; In addition, the electric contact material be loaded in small area analysis current breaker can reduce the rate of consumption after overload trial.In addition, the electric contact material be loaded in big current current breaker also contains wolfram varbide, thus can prevent the deposition after the blocking test of short-circuit test.
Brief Description Of Drawings
Fig. 1 is the side elevational view of the configuration relation illustrated in the closing condition of fixed side contact parts and drawer at movable side contact element, wherein, described fixed side contact parts and described drawer at movable side contact element constitute the current breaker of the electric contact material be wherein equipped with as one embodiment of the present invention;
Fig. 2 is the side elevational view of the configuration relation illustrated in the open mode of fixed side contact parts and drawer at movable side contact element, wherein, described fixed side contact parts and described drawer at movable side contact element constitute the current breaker of the electric contact material be wherein equipped with as one embodiment of the present invention.
Embodiment
First, the structure of the current breaker of the electric contact material be equipped with as one embodiment of the present invention is described.
As depicted in figs. 1 and 2, current breaker 10 has fixed side contact parts 30 and drawer at movable side contact element 20, wherein, drawer at movable side contact element 20, can the mode of movement repeatedly be configured, makes it can touch fixed side contact parts 30 or can away from fixed side contact parts 30.Fixed side contact parts 30 are made up of the conjugant of electric contact material 31 and metal substrate 32.Drawer at movable side contact element 20 is made up of the conjugant of electric contact material 21 and metal substrate 22.According to the electric contact material 31 of the embodiment of the present invention part for the fixed side contact parts 30 of current breaker 10.In addition, the electric contact material 31 shown in Fig. 1 and Fig. 2 is an example according to " electric contact material " of the present invention.
In fixed side contact parts 30, electric contact material 31 and metal substrate 32 being engaged with each other as junction surface, via welding material 4 above using junction surface 32a (itself and metal substrate 32 side form one).In drawer at movable side contact element 20, electric contact material 21 and metal substrate 22 being engaged with each other as junction surface, via welding material 4 above using junction surface (itself and metal substrate 22 side form one).
Because constitute drawer at movable side contact element 20 and fixed side contact parts 30 like this, so make: when the electric current of the permissible current value exceeding current breaker 10 flows through the specified time, built-in contact tripping device (not shown) work, thus, the state that the electric contact material 21 that the state (closing condition) state of current breaker 10 being contacted the electric contact material 31 of fixed side contact parts 30 from the electric contact material 21 of drawer at movable side contact element 20 as shown in Figure 1 transfers to drawer at movable side contact element 20 is as shown in Figure 2 separated from electric contact material 31 moment of fixed side contact parts 30 to arrow Q direction, thus breaking current.In addition, as depicted in figs. 1 and 2, in fixed side contact parts 30, the end side of metal substrate 32 (wherein not arranging electric contact material 31) is connected with the first side (mains side) terminal of current breaker 10, simultaneously, in drawer at movable side contact element 20, the end of metal substrate 22 (wherein not arranging electric contact material 21) is connected with the second side (load side) terminal of current breaker 10.
First, in one aspect of the present invention, being loaded on load current value is that the electric contact material 21 of drawer at movable side in the big current current breaker 10 of about 100 ~ 3200A is formed by silver-wolfram varbide (Ag-WC) based material, the electric contact material 31 of fixation side is formed by silver-graphitic (Ag-Gr) based material, the graphite of 7 quality % is less than or equal to containing being more than or equal to 4 quality %, remainder contains silver and inevitable impurity, amount of deflection is more than or equal to 0.5mm, Vickers' hardness is more than or equal to 55, and oxygen level is less than or equal to 100ppm.
Like this, more than certain particular value is relatively increased to the hardness under major general's electric contact material 31 normal temperature, in addition, amount of deflection is increased to more than certain particular value relatively, oxygen level is suppressed below particular value, being formed electric contact material 31 by flowing through big current in indeformable mode under febrile state (high temperature), the consumption after short-circuit test can be reduced thus.
When the content of graphite in silver-graphitic (Ag-Gr) based material increases, the graphite particle of fine dispersion in material plays pin effect, and therefore, material is reinforced.Thus, improve hardness and the bending strength of material.Graphite containing quantity not sufficient 4 quality % time, pin effect can not be obtained.When the content of graphite is more than 7 quality %, pin effect is superfluous, and therefore amount of flexibility diminishes.
In the short-circuit test using big current, because impact large, so the material that desired strength is relatively large, but in order to tolerate the current breaker opening and closing repeatedly (repeated stock) in overload trial, amount of flexibility is needed to be more than or equal to 0.5mm.When amount of flexibility is less than 0.5mm, the toughness of material is low, and therefore, above-mentioned repeated stock causes electric contact material 31 that crackle occurs.But owing to manufacturing upper difficulty, amount of flexibility is preferably less than or equal to 2mm.At this, so-called " in manufacture difficulty ", thinks to increase amount of flexibility in any case even if refer to, 2mm is also the boundary on manufacturing.
In the short-circuit test using big current, because impact large, so in order to tolerate this impact, need Vickers' hardness to be more than or equal to 55, when Vickers' hardness is less than 55, in the short-circuit test that contact load is large, the hardness of material is not enough, therefore can not maintain contact configuration.In addition, in overload trial, because contact load is little, so contact configuration is hardly by the impact of Vickers' hardness.But because when hardness is excessive, contact contact resistance each other increases, therefore preferably Vickers' hardness is less than or equal to 150.
When oxygen level is more than 100ppm, because the height of the thousands of degree produced during short-circuit test is warm, the oxygen existed in the material becomes gas, therefore makes a part for the base material of electric contact material 31 disperse.Thus the ratio that electric contact material 31 consumes increases.In addition, in overload trial, because contact load is little, so the ratio that electric contact material 31 consumes is hardly by the impact of oxygen level.But owing to manufacturing upper difficulty, preferred oxygen level is more than or equal to 20ppm.At this, so-called " in manufacture difficulty ", thinks to reduce oxygen level in any case even if refer to, 20ppm is also the boundary on manufacturing.
In electric contact material 31 according to an aspect of the present invention, in the short-circuit test using big current, because impact large, so in order to tolerate this impact, preferred bending strength is more than or equal to 210MPa.When bending strength is less than 210MPa, in the short-circuit test that contact load is large, because the physical strength of material is not enough, electric contact material 31 is damaged.In addition, in overload trial, because contact load is little, so hardly by the impact of bending strength.But owing to manufacturing upper difficulty, preferred bending strength is less than or equal to 300MPa.At this, so-called " in manufacture difficulty ", thinks to increase bending strength in any case even if refer to, 300MPa is also the boundary on manufacturing.
In electric contact material 31 according to an aspect of the present invention, the median size of preferred graphite is more than or equal to 40nm and is less than or equal to 8 μm.When the median size of graphite is less than 40nm, because graphite particle is meticulous, so fill up graphite particle thickly between silver particles.Therefore, the area that silver particles contacts with each other extremely reduces.Originally, silver played the effect of the intensity keeping electric contact material 31, but under the state that silver particles contact surface is each other minimum, even if apply pressure, silver can not keep intensity, is therefore difficult to be formed into body.As a result, be difficult to manufacture electric contact material 31.In addition, when the median size of graphite is more than 8 μm, the hardness of electric contact material 31 or bending strength decline.
In addition, in order to prevent short-circuit test blocking test after deposition, electric contact material 31 is according to an aspect of the present invention preferably also containing wolfram varbide.Because electric contact material 31 is also containing wolfram varbide (WC), therefore hardness or the bending strength of electric contact material 31 can be improved further, such as, Vickers' hardness can be made to be more than or equal to 70, bending strength is more than or equal to 230MPa.Thus, more effectively can reduce the consumption after short-circuit test.
In silver-graphitic (Ag-Gr) based material, graphite particle such as disperses with fibrous form.In short-circuit test, when contact contacts with each other, produce the high heat of thousands of degree, therefore silver is easy to liquate.Thus contact is deposition each other.Therefore, when using the electric contact material 31 formed by silver-graphitic-wolfram varbide (Ag-Gr-WC) based material also containing wolfram varbide, silver-colored emersion can be prevented to the surface of electric contact material 31, therefore, in short-circuit test, even if contact contacts with each other and produces high heat, silver also not easily liquate.As a result, the deposition after the blocking test of short-circuit test can be prevented.
In this situation, the median size of preferred wolfram varbide is more than or equal to 40nm and is less than or equal to 3 μm, and the content of wolfram varbide is more than or equal to 2 quality % and is less than or equal to 4 quality %.When the median size of wolfram varbide is less than 40nm, be difficult to the powder making wolfram varbide.When the median size of wolfram varbide is more than 3 μm, the intensity at electric contact material 31 position is uneven.When the position that intensity is low links up, after short-circuit test, electric contact material 31 is optionally consumed.When wolfram varbide containing quantity not sufficient 2 quality % time, can not suppress the liquate of silver, therefore deposit resistance property is poor, and the effect of hardness of raising electric contact material 31 is little simultaneously.When the content of wolfram varbide is more than 4 quality %, because the specific conductivity of electric contact material 31 is deteriorated, so easily generate heat.Therefore, during short circuit, the consumption quantitative change of electric contact material 31 is many.
More preferably the median size of wolfram varbide is more than or equal to 40nm and is less than or equal to 150nm.When the median size of wolfram varbide is more than or equal to 40nm and is less than or equal to 150nm, tungsten carbide particle can be made to evenly spread in silver, therefore, it is possible to more effectively suppress the liquate of silver.Thus, the deposition after the blocking test of short-circuit test can be prevented.That is, the deposit resistance property energy of electric contact material 31 can be improved.When the median size of wolfram varbide is more than 150nm, because there is a large amount of tungsten carbide particle on the surface of electric contact material 31, easily generate heat.Therefore, during short circuit, the consumption quantitative change of electric contact material 31 is many.
When making electric contact material 31 by silver-graphitic-wolfram varbide (Ag-Gr-WC) based material also containing wolfram varbide, more preferably the median size of graphite is more than or equal to 1 μm and be less than or equal to 5 μm.When the median size of graphite be more than or equal to 1 μm and be less than or equal to 5 μm, graphite can be made to be distributed to equably in electric contact material, therefore, it is possible to strengthening electric contact material.Thus, hardness and the bending strength of electric contact material can be improved.When the median size of graphite is less than 1 μm, after mixing raw material powder, thin graphite particle and tungsten carbide particle fill up thickly between silver particles.Therefore, the area that silver particles contacts with each other extremely reduces.Originally, silver played the effect of the intensity keeping electric contact material 31, but under the state that silver particles contact surface is each other minimum, even if apply pressure, silver can not keep intensity, is therefore difficult to be formed into body.In this case, compared with the silver-graphitic based material only containing graphite particle, the existence of the tungsten carbide particles contacted with each other due to silver particles can be stoped in the same manner as graphite particle, graphite particle allow that minimum grain size becomes large.When the median size of graphite is more than 5 μm, quantity as the graphite particle of the lubricant for making silver particles contact with tungsten carbide particle tails off, therefore, when mixing raw material powder, tungsten carbide particle can not disperse equably but condense, and is difficult to form the homodisperse electric contact material of wolfram varbide.Therefore, likely can not get the effect produced by interpolation wolfram varbide, that is, the effect preventing the deposition after the blocking test of short-circuit test such by more effectively suppressing the liquate of silver.
Next, in another aspect of this invention, being loaded on load current value is that the electric contact material 21 of drawer at movable side in the small area analysis current interrupters 10 of about 1 ~ 60A is formed by silver-wolfram varbide (Ag-WC) based material, the electric contact material 31 of fixation side is formed by silver-graphitic (Ag-Gr) based material, the graphite of 2 quality % is less than or equal to containing being more than or equal to 0.5 quality %, remainder is formed by silver and inevitable impurity, amount of deflection is more than or equal to 0.8mm, Vickers' hardness is more than or equal to 40, and oxygen level is less than or equal to 100ppm.
Like this, amount of flexibility to major general's electric contact material 31 increases to more than certain particular value relatively, in addition, hardness under the normal temperature of electric contact material is increased to more than certain particular value relatively, oxygen level is suppressed below particular value, formed electric contact material 31 in the mode that can tolerate repetitious mechanical shock, thus the consumption after overload trial can be reduced.
In silver-graphitic (Ag-Gr) based material, when the content of graphite increases, the graphite particle of fine dispersion in material plays pin effect, and therefore material is reinforced.Thus, improve hardness and the bending strength of material.Graphite containing quantity not sufficient 0.5 quality % time, pin effect can not be obtained.When the content of graphite is more than 2 quality %, pin effect is superfluous, and amount of flexibility diminishes.
Compared with use big current, impact in the short-circuit test using small area analysis is less, in order to tolerate this impact, the material that desired strength is relatively little, therefore, in order to tolerate the opening and closing repeatedly (repeated load) of the current breaker in overload trial, amount of flexibility is needed to be more than or equal to 0.8mm.When amount of flexibility is less than 0.8mm, because the toughness of material is low, due to above-mentioned repeated load, electric contact material 31 cracks.But owing to manufacturing upper difficulty, preferred amount of flexibility is below 2.5mm.At this, so-called " in manufacture difficulty ", thinks to increase amount of flexibility in any case even if refer to, 2.5mm is also the boundary on manufacturing.
Compared with use big current, the impact in the short-circuit test using small area analysis is less, therefore, in order to tolerate this impact, Vickers' hardness must be more than or equal to 40, when Vickers' hardness is less than 40, in the short-circuit test that contact load is large, because material hardness is not enough, contact configuration can not be maintained.In addition, in overload trial, because contact load is little, so contact configuration is hardly by the impact of Vickers' hardness.But when hardness is excessive, because contact contact electricity resistive is each other large, preferred Vickers' hardness is less than or equal to 100.
When oxygen level is more than 100ppm, because the height of the thousands of degree produced during short-circuit test is warm, the oxygen existed in the material becomes gas, therefore, a part for the base material of electric contact material 31 is dispersed.Thus the ratio that electric contact material 31 consumes increases.In addition, in overload trial, because contact load is little, so this consumption ratio of electric contact material 31 is hardly by the impact of oxygen level.But owing to manufacturing upper difficulty, preferred oxygen level is more than or equal to 30ppm.At this, so-called " in manufacture difficulty ", thinks to reduce oxygen level in any case even if refer to, 30ppm is also the boundary on manufacturing.
In electric contact material 31 according to another aspect of the present invention, compared with use big current, the impact in the short-circuit test using small area analysis is less, and therefore, in order to tolerate this impact, preferred bending strength is more than or equal to 120MPa.When bending strength is less than 120MPa, in the short-circuit test that contact load is large, because the physical strength of material is not enough, electric contact material 31 is damaged.In addition, in overload trial, contact load is little, therefore hardly by the impact of bending strength.But owing to manufacturing upper difficulty, preferred bending strength is less than or equal to 280MPa.At this, so-called " in manufacture difficulty ", increases bending strength in any case even if refer to, 280MPa is also the boundary on manufacturing.
In addition, in electric contact material 31 according to a further aspect in the invention, the median size of preferred graphite is more than or equal to 40nm and is less than or equal to 8 μm.When the median size of graphite is less than 40nm, because graphite particle is meticulous, so graphite particle fills up between silver particles thickly.Therefore, the area that silver particles contacts with each other extremely diminishes.Originally, silver played the effect of the intensity keeping electric contact material 31, but under the state that silver particles contact surface is each other minimum, even if apply pressure, silver can not keep intensity, is therefore difficult to be formed into body.As a result, be difficult to manufacture electric contact material 31.In addition, when the median size of graphite is more than 8 μm, the hardness of electric contact material 31 or bending strength decline.
In addition, the following manufacture electric contact material 31 formed by silver-graphitic (Ag-Gr) based material of the present invention.
First, according to the composition of regulation by silver powder and the powdered graphite true air mix (such as) 30 ~ 60 minutes at (such as) 80 ~ 150Pa.Then, mixed powder is applied to the pressure of (such as) 250 ~ 350MPa, thus formation is compressed into body.This is compressed into body in the reducing gas atmosphere such as (such as) hydrogen of (such as) 850 ~ 950 DEG C of temperature, keeps (such as) 1 ~ 2 hour, thus partially sinter.This is partially sintered body and carry out coinging in the pressure that adds of (such as) 1000 ~ 1200MPa, reach (such as) more than 97% to make true density.By after coinging partially sinter body (such as) 750 ~ 850 DEG C of temperature, in the reducing gas such as inert gas atmosphere or the hydrogen atmosphere such as nitrogen or these mixed-gas atmospheres, keep (such as) 1 ~ 2 hour, thus preheat, then, apply the extrusion pressure of 100 ~ 200GPa, thus carry out extruding processing, to form the shape of regulation.
In addition, the following electric contact material 31 formed by silver-graphitic-wolfram varbide (Ag-Gr-WC) based material of the present invention manufactured containing wolfram varbide.
First, according to the composition of regulation, by silver powder, powdered graphite and the tungsten-carbide powder true air mix (such as) 30 ~ 60 minutes at (such as) 80 ~ 150Pa.Then, mixed powder is applied to the pressure of (such as) 250 ~ 350MPa, thus formation is compressed into body.This is compressed into body and keeps (such as) 1 ~ 2 hour in the reducing gas atmosphere such as (such as) hydrogen of (such as) 850 ~ 950 DEG C of temperature, thus partially sinter.This is partially sintered body and carry out coinging in the pressure that adds of (such as) 1000 ~ 1200MPa, reach (such as) more than 97% to make true density.By after coinging partially sinter body (such as) 750 ~ 850 DEG C of temperature, in the reducing gas such as inert gas atmosphere or the hydrogen atmosphere such as nitrogen or these mixed-gas atmospheres, keep (such as) 1 ~ 2 hour, thus preheat, then, apply the extrusion pressure of 100 ~ 200GPa thus carry out extruding processing, to form the shape of regulation.
As mentioned above, of the present invention by the electric contact material 31 that silver-graphitic (Ag-Gr) is or silver-graphitic-wolfram varbide (Ag-Gr-WC) based material is formed in order to manufacture, have employed extrusion process method.When utilizing extrusion process method to manufacture electric contact material 31, the old powder crystal boundary in raw material powder is torn, and thus, the powder crystal boundary extruding most fragile in powder metallurgy in processome is strengthened.Thus, bending strength or the amount of deflection of material can be improved.In addition, by extrusion process method, material is densified, therefore, it is possible to improve the hardness of material.On the other hand, when adopting sintering process, the old powder crystal boundary in raw material powder still remains in sintered compact, therefore, and extrudes compared with processome, obtains the sintered compact that physical strength is low.
In manufacture method of the present invention, as mentioned above, raw material powder is mixed in a vacuum.Proportion as the silver powder of raw material powder is about 4.8 times of powdered graphite proportion, so be difficult to silver powder and powdered graphite dispersing and mixing equably in an atmosphere.Therefore, the electric contact material 31 utilizing the mixed powder be mixed to get in an atmosphere to make can not obtain by dispersion-strengthened the produced effect of uniform particle, so hardness and bending strength decline.On the other hand, the electric contact material 31 using the mixed powder be mixed to get in a vacuum to make, can obtain by dispersion-strengthened the produced effect of uniform particle.
In addition, in manufacture method of the present invention, as mentioned above, body will be compressed into and partially sinter in reducing gas atmosphere, so the oxygen be attached on raw material powder surface can be removed.As a result, the consumption after can making the obtained overload trial of electric contact material 31 or the blocking test of short-circuit test is reduced.On the other hand, when body will be compressed into be partially sintered in inert gas atmosphere, although the oxygen be mixed into when there is not sintering, because the oxygen be attached on raw material powder surface can not be removed, so the consumption after the blocking test of electric contact material increases.
In addition, in manufacture method of the present invention, as mentioned above, will partially sinter after body carries out coinging and carry out extruding processing again, therefore, the density of material when preheating reaches more than 98%.Therefore, it is possible to reduce the amount entering into the oxygen of material when preheating in process furnace.Thus, such as, the Control for Oxygen Content in the electric contact material 31 finally obtained can be less than or equal to 100ppm being more than or equal to 20ppm.On the other hand, when not to partially sinter body carry out coinging, the density of material is about 90%, so the amount entering into the oxygen of material when preheating in process furnace increases.Therefore, there is the oxidation of silver, so the oxygen level in the electric contact material 31 finally obtained increases.
Embodiment
Below, the embodiment of carrying out the effect in order to confirm above-mentioned embodiment and the comparative experiments of comparative example are described.
[embodiment A]
In the present embodiment, as the embodiment corresponding with above-mentioned embodiment, make the electric contact material 31 of the fixation side of following examples A1 ~ A9.In addition, adopt the method identical with embodiments of the invention, make the electric contact material 31 of the fixation side of content of graphite, amount of deflection, Vickers' hardness and the oxygen level Comparative examples A 1 ~ A8 beyond the scope of the invention.In addition, as the comparative example corresponding with conventional example, the electric contact material 31 of the fixation side of Comparative examples A 11 ~ A16, A21 ~ A26 below having made, A31 ~ A36, A41 ~ A46.Use respectively and these electric contact materials 31 are housed respectively and the load current value that the forms big current current breaker that is 100A, carried out the blocking test of overload trial and short-circuit test.In addition, the electric contact material 21 of drawer at movable side employs silver containing 50 quality %, remainder is the material of wolfram varbide.
The graphite (Gr) used to make electric contact material 31 in examples and comparative examples of the present invention has been shown in following table 1) median size of powder, graphite (Gr) content in made electric contact material 31, the amount of deflection of electric contact material 31, bending strength, hardness, oxygen level and density.In addition, the evaluation result of the rate of consumption of the electric contact material 31 after the rate of consumption of the electric contact material 31 after about overload trial, short-circuit test is also shown in table 1.In addition, in table 1, the numerical value beyond the numeric representation scope of the invention of picture underscore.
In addition, the evaluation of the rate of consumption after about the method for the measuring method of the amount of deflection of electric contact material 31, bending strength, hardness, oxygen level and density, the overload trial of big current current breaker and the blocking test of short-circuit test, these blocking tests is described after.
(embodiment A 1 ~ A9), (Comparative examples A 1 ~ A8)
In embodiment A 1 ~ A9 and Comparative examples A 1 ~ A8, make the electric contact material 31 of silver-graphitic (Ag-Gr) based material containing graphite (Gr) in the following manner with the content shown in table 1.
Utilize ball mill by graphite (Gr) powder of median size shown in table 1 and median size be 3 μm silver (Ag) powder in a vacuum (100Pa) mix 30 minutes, make the content of graphite had shown in table 1.With pressing machine, the pressure of 300MPa is applied to obtained mixed powder, thus form that thickness is 300mm, external diameter is that the discoid of 80mm is compressed into body.This being compressed into body is keep 1 hour in the hydrogen (it is reducing gas atmosphere) of 950 DEG C in temperature, thus partially sinters.This is partially sintered body and carry out coinging in the pressure that adds of 1100MPa, reach more than 97% to make true density.The body that partially sinters after coinging is kept 2 hours in the nitrogen (its for inert gas atmosphere) of 800 DEG C of temperature, thus preheats, the extrusion pressure of after-applied 100GPa, thus extrude that to be processed into cross section be the square rhoptry of 10mm.Obtained rhoptry is cut into the thickness of 1mm, thus makes electric contact material 31.In addition, although powdered graphite of attempting using median size to be 10nm adopt aforesaid method to make electric contact material, cannot manufacture.
(Comparative examples A 11 ~ A16)
In Comparative examples A 11 ~ A16, according to the operation identical with above-described embodiment A1 ~ A9, make the electric contact material 31 of silver-graphitic (Ag-Gr) based material of graphitiferous (Gr) with the content shown in table 1, difference is the operation of not carrying out partially sintering body coinging.
(Comparative examples A 21 ~ A26)
In Comparative examples A 21 ~ A26, according to the operation identical with above-described embodiment A1 ~ A9, make the electric contact material 31 of silver-graphitic (Ag-Gr) based material of graphitiferous (Gr) with the content shown in table 1, difference is silver powder and powdered graphite to mix in an atmosphere.
(Comparative examples A 31 ~ A36)
In Comparative examples A 31 ~ A36; according to the operation identical with above-described embodiment A1 ~ A9; make the electric contact material 31 of silver-graphitic (Ag-Gr) based material of graphitiferous (Gr) with the content shown in table 1, difference is that by being compressed into body be keep 1 hour to partially sinter in the nitrogen (it is shielding gas atmosphere) of 950 DEG C in temperature.
(Comparative examples A 41 ~ A46)
In Comparative examples A 41 ~ A46, with the content shown in table 1, make the electric contact material 31 of silver-graphitic (Ag-Gr) based material of graphitiferous (Gr) in the following manner.
By graphite (Gr) powder of median size shown in table 1 and median size be 3 μm silver (Ag) powder in an atmosphere handwork mix 30 minutes, make the content of graphite had shown in table 1.With pressing machine, obtained mixed powder is applied to the pressure of 300MPa, thus formation planeform is that the tabular that 10mm is square, thickness is 1mm is compressed into body.This is compressed into body and in the vacuum of temperature 900 DEG C, keeps 1 hour to partially sinter.This is partially sintered body and carry out coinging under the pressure of 500MPa, reach more than 97% to make true density.Like this, electric contact material 31 is obtained.
(amount of deflection)
The amount of deflection [mm] of made electric contact material measures according to JIS H5501.
(bending strength)
The raw material identical with made electric contact material is adopted to make the sample of the proof bend test of 5mm × 2mm × 30mm size.Use this sample, under the condition of distance between the fulcrum 15mm, head velocity 1mm/min, measure bending strength (MPa).
(hardness)
Use Vickers hardness tester, according to JIS Z 2244, determine the Vickers' hardness [HV] of made electric contact material.
(oxygen level)
When measuring the oxygen level remained in made electric contact material, use the oxygen analyzer device (model BMGA520) of Horiba Ltd, undertaken by infrared absorption.
(density)
By by the weight of electric contact material divided by the volume (calculated value that the product of length x width x gauge obtains) of electric contact material and the density calculated calculates the density (relative density) of made electric contact material divided by the theoretical density of each material.
(blocking test (overload trial) of big current current breaker)
In overload trial, under the load voltage of 220V, set the breaking current of 600A.As test method, carry out 50 CO tasks and (in the loop that the breaking current of 600A flows through under load voltage 220V, place current breaker, and under the state that switch is OFF, switch is switched to by force ON state with the test of instantaneous breaking current).And, the rate of consumption of electric contact material 31 after overload trial is calculated by following formula.In table 1, as the evaluation of rate of consumption, represent with " ◎ " when the rate of consumption calculated is less than 5%, represent by "○" when being less than 10%, represent by "×" during more than 10%.
(rate of consumption of electric contact material)=[{ (testing the thickness of front electric contact material)-(thickness of the rear electric contact material of test) }/(thickness of the front electric contact material of test)] × 100% ... (formula 1)
(blocking test (short-circuit test) of big current current breaker)
In short-circuit test, under 220V load voltage, set the breaking current of 5000A.As test method, carried out O task successively (makes breaking current flow through under the switch of current breaker is ON state, and make the test that electric current interdicts) and CO task (in the loop that the breaking current of 5000A flows through under load voltage 220V, place current breaker, and under the state that switch is OFF, switch is switched to by force ON state with the test of instantaneous breaking current).That is, in this short-circuit test, as operation task, an O task and three CO tasks have been carried out successively.And, the rate of consumption of the electric contact material after short-circuit test 31 is calculated by above-mentioned (formula 1).In table 1, as the evaluation of rate of consumption, represent with " ◎ " when the rate of consumption calculated is less than 10%, represent by "○" when being less than 40%, represent by "×" during more than 40%.
Table 1
As known from Table 1, load current value is in the big current current breaker of 100A, relatively increase to the Vickers' hardness under the normal temperature of major general's electric contact material and be more than or equal to 55, in addition, amount of flexibility is increased to relatively and is more than or equal to 0.5mm, and oxygen level is suppressed be less than or equal to 100ppm, the mode do not deformed under the state (under high temperature) of generating heat to flow through at big current is formed electric contact material, thus the rate of consumption that can not only reduce after overload trial, and the consumption after short-circuit test can be reduced.
[Embodiment B]
In the present embodiment, as the embodiment corresponding with above-mentioned embodiment, the electric contact material 31 of the fixation side of the Embodiment B 1 ~ B9 below having made.In addition, adopt the method same with embodiments of the invention, make the electric contact material 31 of the fixation side of content of graphite, amount of deflection, Vickers' hardness and the oxygen level comparative example B1 ~ B8 outside the scope of the invention.In addition, as the comparative example corresponding with conventional example, the electric contact material 31 of the fixation side of comparative example B11 ~ B16, B21 ~ B26 below having made, B31 ~ B36, B41 ~ B46.Use respectively and these electric contact materials 31 are housed respectively and the small area analysis current breaker of load current value 30A that forms, carry out the blocking test of overload trial and short-circuit test.In addition, the electric contact material 21 of drawer at movable side employs silver containing 50 quality %, remainder is the material of wolfram varbide.
The content of the graphite (Gr) in the median size of graphite (Gr) powder that following table 2 shows the electric contact material 31 in order to make examples and comparative examples of the present invention and uses, made electric contact material 31, the amount of deflection of electric contact material 31, bending strength, hardness, oxygen level and density.In addition, table 2 also shows the evaluation result of the rate of consumption of the electric contact material 31 after the rate of consumption of the electric contact material 31 after about overload trial, short-circuit test.In addition, the numerical value beyond the numeric representation scope of the invention of drawing underscore in table 2.
In addition, the measuring method of the amount of deflection of electric contact material 31, bending strength, hardness, oxygen level and density is identical with above-described embodiment A.Describe the evaluation of the rate of consumption after the blocking test method of the overload trial of small area analysis current breaker and short-circuit test, these blocking tests below.
(Embodiment B 1 ~ B9), (comparative example B1 ~ B8)
In Embodiment B 1 ~ B9 and comparative example B1 ~ B8, with the content shown in table 2, make the electric contact material 31 of silver-graphitic (Ag-Gr) based material of graphitiferous (Gr) in the following manner.
Utilize ball mill by graphite (Gr) powder of median size shown in table 2 and median size be 3 μm silver (Ag) powder in a vacuum (100Pa) mix 30 minutes, make the content of graphite had shown in table 2.With pressing machine, the pressure of 300MPa is applied to obtained mixed powder, thus form thickness 300mm, the discoid of external diameter 80mm be compressed into body.This being compressed into body is keep 1 hour in the hydrogen (it is reducing gas atmosphere) of 950 DEG C in temperature, thus partially sinters.This is partially sintered body and carry out coinging in the pressure that adds of 1100MPa, reach more than 97% to make true density.The body that partially sinters after coinging is kept 2 hours in the nitrogen (its for inert gas atmosphere) of 800 DEG C of temperature, thus preheats, the extrusion pressure of after-applied 100GPa, thus extrude that to be processed into cross section be the square rhoptry of 10mm.Obtained rhoptry is cut into the thickness of 1mm, thus makes electric contact material 31.In addition, although powdered graphite of attempting using median size to be 10nm adopt aforesaid method to make electric contact material, cannot manufacture.
(comparative example B11 ~ B16)
In comparative example B11 ~ B16, according to the operation identical with above-described embodiment B1 ~ B9, make the electric contact material 31 of silver-graphitic (Ag-Gr) based material of graphitiferous (Gr) with the content shown in table 2, difference is the operation of not carrying out partially sintering body coinging.
(comparative example B21 ~ B26)
In comparative example B21 ~ B26, according to the operation identical with above-described embodiment B1 ~ B9, make the electric contact material 31 of silver-graphitic (Ag-Gr) based material of graphitiferous (Gr) with the content shown in table 2, difference is silver powder and powdered graphite to mix in an atmosphere.
(comparative example B31 ~ B36)
In comparative example B31 ~ B36; according to the operation identical with above-described embodiment B1 ~ B9; make the electric contact material 31 of silver-graphitic (Ag-Gr) based material of graphitiferous (Gr) with the content shown in table 2, difference is that by being compressed into body be keep 1 hour to partially sinter in the nitrogen (it is shielding gas atmosphere) of 950 DEG C in temperature.
(comparative example B41 ~ B46)
In comparative example B41 ~ B46, make the electric contact material 31 of silver-graphitic (Ag-Gr) based material of graphitiferous (Gr) in the following manner with the content shown in table 2.
By graphite (Gr) powder of median size shown in table 2 and median size be 3 μm silver (Ag) powder in an atmosphere handwork mix 30 minutes, make the content of graphite had shown in table 2.With pressing machine, obtained mixed powder is applied to the pressure of 300MPa, thus formation planeform is that the tabular that 10mm is square, thickness is 1mm is compressed into body.This being compressed into body is keep 1 hour in the vacuum of 900 DEG C in temperature, thus partially sinters.This is partially sintered body and carry out coinging under the pressure of 500MPa, reach more than 97% to make true density.Like this, electric contact material 31 is obtained.
(blocking test (overload trial) of small area analysis current breaker)
In long duration test, under the load voltage of 220V, set the breaking current of 180A.As test method, 50 CO tasks (place current breaker in the loop that the breaking current of 180A flows through under load voltage 220V, under switch is OFF state, switch is transformed into by force ON state with the test of instantaneous breaking current) are carried out.And, the rate of consumption of the electric contact material after overload trial 31 is calculated by above-mentioned (formula 1).In table 2, as the evaluation of rate of consumption, represent with " ◎ " when the rate of consumption calculated is less than 5%, represent by "○" when being less than 10%, represent by "×" during more than 10%.
(blocking test (short-circuit test) of small area analysis current breaker)
In short-circuit test, under the load voltage of 220V, set the breaking current of 300A.As test method, carried out O task successively (makes breaking current flow through under the switch of current breaker is ON state, and the test that electric current is interdicted) and CO task (in the loop that the breaking current of 300A flows through under load voltage 220V, place current breaker, under switch is OFF state, switch is transformed into by force ON state with the test of instantaneous breaking current).That is, in this short-circuit test, as operation task, an O task and three CO tasks have been carried out successively.And, the rate of consumption of the electric contact material after short-circuit test 31 is calculated by above-mentioned (formula 1).In table 2, as the evaluation of rate of consumption, represent with " ◎ " when the rate of consumption calculated is less than 10%, represent by "○" when being less than 40%, represent by "×" during more than 40%.
Table 2
As known from Table 2, be in the small area analysis current breaker of 30A at load current value, amount of flexibility to major general's electric contact material relatively increases to and is more than or equal to 0.8mm, in addition, Vickers' hardness under the normal temperature of electric contact material is increased to relatively and is more than or equal to 40, oxygen level is suppressed be less than or equal to 100ppm, electric contact material is formed in the mode that can tolerate repetitious mechanical shock, thus the rate of consumption that can not only reduce after short-circuit test, and the consumption after overload trial can be reduced.
[Embodiment C]
In the present embodiment, as the embodiment corresponding with above-mentioned embodiment, the electric contact material 31 of the fixation side of the Embodiment C 1 ~ C20 below having made.In addition, as the comparative example corresponding with conventional example, the electric contact material 31 of the fixation side of comparative example C107, C207, C307, C407 below having made.Use respectively and these electric contact materials 31 are housed respectively and the big current current breaker of load current value 100A that forms, carried out the blocking test of overload trial and short-circuit test.In addition, the electric contact material 21 of drawer at movable side employs silver containing 50 quality %, remainder is the material of wolfram varbide.
The amount of deflection of the content of wolfram varbide (WC), electric contact material 31, bending strength, hardness, oxygen level and density in graphite (Gr) content of the median size of graphite (Gr) powder that following table 3 shows electric contact material 31 in order to make examples and comparative examples of the present invention and uses, made electric contact material 31, the median size of wolfram varbide (WC) powder, made electric contact material 31.In addition, table 3 also shows the evaluation result of the rate of consumption of the electric contact material 31 after the rate of consumption of the electric contact material 31 after about overload trial, short-circuit test.In addition, the numerical value beyond the numeric representation scope of the invention of drawing underscore in table 3.
In addition, the measuring method of the amount of deflection of electric contact material 31, bending strength, hardness, oxygen level and density is identical with above-described embodiment A.The overload trial of big current current breaker is also identical with above-described embodiment A with the rate of consumption evaluation after the blocking test method of short-circuit test, these blocking tests.
(Embodiment C 1 ~ C20)
In Embodiment C 1 ~ C20, make the electric contact material 31 of silver-graphitic-wolfram varbide (Ag-Gr-WC) based material of graphitiferous (Gr) and wolfram varbide (WC) in the following manner with the content shown in table 3.
Utilize ball mill by silver (Ag) powder of graphite (Gr) powder of median size shown in table 3 and wolfram varbide (WC) powder and median size 3 μm in a vacuum (100Pa) mix 30 minutes, make that there is the content of graphite shown in table 3 and tungsten carbide content.With pressing machine, the pressure of 300MPa is applied to obtained mixed powder, thus form thickness 300mm, the discoid of external diameter 80mm be compressed into body.This being compressed into body is keep 1 hour in the hydrogen (it is reducing gas atmosphere) of 950 DEG C in temperature, thus partially sinters.This is partially sintered body and carry out coinging in the pressure that adds of 1100MPa, reach more than 97% to make true density.The body that partially sinters after coinging is kept 2 hours in the nitrogen (its for inert gas atmosphere) of 800 DEG C of temperature, thus preheats, the extrusion pressure of after-applied 100GPa, thus extrude that to be processed into cross section be the square rhoptry of 10mm.Obtained rhoptry is cut into the thickness of 1mm, thus makes electric contact material 31.
(comparative example C107)
In comparative example C107, according to the operation identical with above-described embodiment C1 ~ C20, as shown in table 3, with the median size identical with Embodiment C 7 and content, make the electric contact material 31 of silver-graphitic-wolfram varbide (Ag-Gr-WC) based material of graphitiferous (Gr) and wolfram varbide (WC), difference is the operation of not carrying out partially sintering body coinging.
(comparative example C207)
In comparative example C207, according to the operation identical with above-described embodiment C1 ~ C20, as shown in table 3, with the median size identical with Embodiment C 7 and content, make the electric contact material 31 of silver-graphitic-wolfram varbide (Ag-Gr-WC) based material of graphitiferous (Gr) and wolfram varbide (WC), difference is silver powder, powdered graphite and tungsten-carbide powder to mix in an atmosphere.
(comparative example C307)
In comparative example C307; according to the operation identical with above-described embodiment C1 ~ C20; as shown in table 3; with the median size identical with Embodiment C 7 and content; make the electric contact material 31 of silver-graphitic-wolfram varbide (Ag-Gr-WC) based material of graphitiferous (Gr) and wolfram varbide (WC), difference be by be compressed into body in temperature be in the nitrogen (it is shielding gas atmosphere) of 950 DEG C maintenance 1 hour to partially sinter.
(comparative example C407)
In comparative example C407, with the content shown in table 3, make the electric contact material 31 of silver-graphitic-wolfram varbide (Ag-Gr-WC) based material of graphitiferous (Gr) and wolfram varbide (WC) in the following manner.
By silver (Ag) powder of graphite (Gr) powder of median size shown in table 3, wolfram varbide (WC) powder and median size 3 μm in an atmosphere handwork mix 30 minutes, make the content of graphite had shown in table 3.With pressing machine, obtained mixed powder is applied to the pressure of 300MPa, thus formation planeform is that the tabular that 10mm is square, thickness is 1mm is compressed into body.This is compressed into body and in the vacuum of temperature 900 DEG C, keeps 1 hour to partially sinter.This is partially sintered body and carry out coinging under the pressure of 500MPa, reach more than 97% to make true density.Like this, electric contact material 31 is obtained.
As known from Table 3, even if be in the big current current breaker of 100A at the load current value of the electric contact material 31 employing silver-graphitic-wolfram varbide (Ag-Gr-WC) based material, relatively increase to the Vickers' hardness under the normal temperature of major general's electric contact material and be more than or equal to 55, in addition, amount of flexibility is increased to relatively and is more than or equal to 0.5mm, and oxygen level is suppressed be less than or equal to 100ppm, the mode do not deformed under the state (high temperature) of generating heat to flow through at big current is formed electric contact material, thus the rate of consumption that can not only reduce after overload trial, and the consumption that can reduce after short-circuit test.
[embodiment D]
In the present embodiment, as the embodiment corresponding with above-mentioned embodiment, the electric contact material 31 of the fixation side of the embodiment D1 ~ D9 below having made.Adopt the method identical with the embodiment of the present invention, make the electric contact material 31 of the fixation side of the median size of tungsten-carbide powder and the Comparative Example D 1 ~ D4 of the content of wolfram varbide outside preferable range of the present invention.Use respectively and these electric contact materials 31 are housed respectively and the load current value that the forms big current current breaker that is 100A, to carry out deposition test.In addition, the electric contact material 21 of drawer at movable side employs silver containing 50 quality %, remainder is the material of wolfram varbide.
The content of wolfram varbide (WC) in the content of graphite (Gr), the median size of wolfram varbide (WC) powder, made electric contact material 31 in the median size of graphite (Gr) powder that following table 4 shows electric contact material 31 in order to make examples and comparative examples of the present invention and uses, made electric contact material 31.In addition, the evaluation result of relevant deposition test is also shown in table 4.In addition, the numerical value outside the numeric representation preferable range of the present invention of drawing underscore in table 4.
In addition, the measuring method of the amount of deflection of electric contact material 31, bending strength, hardness, oxygen level and density is identical with above-described embodiment A.The method of the deposition test of big current current breaker, the evaluation of deposition test are described below.
(embodiment D1 ~ D9), (Comparative Example D 1 ~ D4)
In embodiment D1 ~ D9 and Comparative Example D 1 ~ D4, make the electric contact material 31 of silver-graphitic-wolfram varbide (Ag-Gr-WC) based material of graphitiferous (Gr) and wolfram varbide (WC) in the following manner with the content shown in table 4.
Utilize ball mill by silver (Ag) powder of graphite (Gr) powder of median size shown in table 4, wolfram varbide (WC) powder and median size 3 μm in a vacuum (100Pa) mix 30 minutes, make that there is the content of graphite shown in table 4 and tungsten carbide content.Use pressing machine to the pressure of obtained mixed powder applying 300MPa, thus defines thickness 300mm, the discoid of external diameter 80mm is compressed into body.This is compressed into body and keeps 1 hour to partially sinter in the hydrogen (it is reducing gas atmosphere) of temperature 950 DEG C.This is partially sintered body and carry out coinging in the pressure that adds of 1100MPa, reach more than 97% to make true density.The body that partially sinters after coinging is kept 2 hours in the nitrogen (its for inert gas atmosphere) of 800 DEG C of temperature, to preheat, the extrusion pressure of after-applied 100GPa, thus extrude that to be processed into cross section be the square rhoptry of 10mm.Obtained rhoptry is cut into the thickness of 1mm, thus makes electric contact material 31.
(the deposition test of big current current breaker)
In deposition test, under 265V load voltage, set the breaking current of 5000A.As test method, carry out O task successively (makes breaking current flow through under the switch of current breaker is ON state, and the test that electric current is interdicted) and CO task (in the loop that the breaking current of 5000A flows through under load voltage 265V, place current breaker, under switch is OFF state, switch is transformed into by force ON state with the test of instantaneous breaking current).That is, in the test of this deposition, as operation task, an O task and five CO tasks have been carried out successively.And, the deposition situation of electric contact material 31 in deposition test or after deposition test is evaluated.In table 4, as the evaluation of deposition situation, contact does not have to represent with " ◎ " during deposition completely, the situation (light deposition) can being sloughed deposition by the ON/OFF of current breaker is simply represented by "○", and the situation (remelting is applied) can not being sloughed deposition by the ON/OFF of current breaker is simply represented by "×".
Table 4
As known from Table 4, in the big current current breaker of load current value 100A, be less than or equal to 150nm by being more than or equal to 40nm by the median size of wolfram varbide, the content of wolfram varbide is more than or equal to 2 quality % and the silver-graphitic-wolfram varbide based material being less than or equal to 4 quality % forms electric contact material, can prevent the deposition after the blocking test of short-circuit test.
Embodiment of disclosure and embodiment all should be thought exemplary instead of restrictive in every respect.Scope of the present invention is not limited to above embodiment and embodiment, but is represented by claims, and intention comprises all modifications in the meaning and scope that are equal to claims and distortion.
Such as, in the above-described embodiment and examples, show the example applying electric contact material 31 of the present invention in the fixed side contact parts 30 of current breaker 10, but the present invention is not limited to this example, any one in the drawer at movable side contact element 20 of current breaker 10 or fixed side contact parts 30 also can use electric contact material of the present invention.
In addition, in the above-described embodiment and examples, show the example employing electric contact material 31 of the present invention in the current breaker 10 as an example of shutter, but the present invention is not limited to this example, such as, also electric contact material of the present invention can be used in the shutter (switching device) outside the current breaker such as electromagnetism shutter.
Industrial applicibility
Electric contact material of the present invention can be encased in big current current breaker that load current value is 100 ~ 3200A or load current value is use in the small area analysis current breaker of 1 ~ 60A.
Nomenclature
10 current breakers
21,31 electric contact materials
Claims (8)
1. an electric contact material, the graphite of 7% (quality) is less than or equal to containing being more than or equal to 4% (quality), remainder comprises silver and inevitable impurity, its amount of deflection is more than or equal to 0.5mm, Vickers' hardness is more than or equal to 55, and oxygen level is less than or equal to 100ppm.
2. electric contact material according to claim 1, wherein bending strength is more than or equal to 210MPa.
3. electric contact material according to claim 1, wherein, the median size of described graphite is more than or equal to 40nm and is less than or equal to 8 μm.
4. electric contact material according to claim 1, also containing wolfram varbide.
5. electric contact material according to claim 4, wherein, the median size of described wolfram varbide is more than or equal to 40nm and is less than or equal to 3 μm, and the content of wolfram varbide is more than or equal to 2% (quality) and is less than or equal to 4% (quality).
6. electric contact material according to claim 5, wherein, the median size of described wolfram varbide is more than or equal to 40nm and is less than or equal to 150nm.
7. a preparation method for electric contact material, it is the preparation method of electric contact material according to claim 1, comprises the following steps:
The step of mixed powder is obtained by silver powder and powdered graphite being mixed in a vacuum;
The step being compressed into body is formed by applying pressure to described mixed powder;
By the described body that is compressed into is remained in reducing gas atmosphere to carry out the step partially sintered;
The step that body carries out coinging is under elevated pressure partially sintered by described; And
By by after described coinging partially sinter body remain in inert gas atmosphere or in reducing gas atmosphere or in the mixed-gas atmosphere of rare gas element and reducing gas to preheat, then apply extrusion pressure to carry out the step extruding processing.
8. a preparation method for electric contact material, it is the preparation method of electric contact material according to claim 4, comprises the following steps:
The step of mixed powder is obtained by silver powder, powdered graphite and tungsten-carbide powder being mixed in a vacuum;
The step being compressed into body is formed by applying pressure to described mixed powder;
By the described body that is compressed into is remained in reducing gas atmosphere to carry out the step partially sintered;
The step that body carries out coinging is under elevated pressure partially sintered by described; And
By by after described coinging partially sinter body remain in inert gas atmosphere or in reducing gas atmosphere or in the mixed-gas atmosphere of rare gas element and reducing gas to preheat, then apply extrusion pressure to carry out the step extruding processing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410043335.1A CN103794385B (en) | 2009-03-24 | 2010-03-03 | Electric contact material |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009-071526 | 2009-03-24 | ||
| JP2009071526 | 2009-03-24 | ||
| PCT/JP2010/001444 WO2010109777A1 (en) | 2009-03-24 | 2010-03-03 | Electrical contact material |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410043335.1A Division CN103794385B (en) | 2009-03-24 | 2010-03-03 | Electric contact material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102362326A CN102362326A (en) | 2012-02-22 |
| CN102362326B true CN102362326B (en) | 2015-03-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201080013341.2A Expired - Fee Related CN102362326B (en) | 2009-03-24 | 2010-03-03 | Electrical contact material |
| CN201410043335.1A Expired - Fee Related CN103794385B (en) | 2009-03-24 | 2010-03-03 | Electric contact material |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410043335.1A Expired - Fee Related CN103794385B (en) | 2009-03-24 | 2010-03-03 | Electric contact material |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP2413337A4 (en) |
| JP (1) | JP4579348B1 (en) |
| CN (2) | CN102362326B (en) |
| WO (1) | WO2010109777A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4898978B2 (en) * | 2010-06-22 | 2012-03-21 | 株式会社アライドマテリアル | Electrical contact material |
| RU176664U1 (en) * | 2017-07-10 | 2018-01-25 | Общество с ограниченной ответственностью "Информационные технологии" (ООО "ИнфоТех") | COMPOSITE ELECTRIC CONTACT |
| CN109243872A (en) * | 2018-09-21 | 2019-01-18 | 靖江市海源有色金属材料有限公司 | A kind of silver graphite base electric contact and preparation method thereof |
| RU198536U1 (en) * | 2019-11-01 | 2020-07-15 | Общество С Ограниченной Ответственностью "Инновационные Технологии На Железнодорожном Транспорте" (Ооо "Итжт") | LOW VOLTAGE SOLENOID RELAY CONTACT PART |
| KR102356988B1 (en) * | 2021-07-08 | 2022-02-08 | 주식회사 유승 | Dispersion Hardened Silver-based Composite for Measuring Device Element of Electronic Parts and Manufacturing Process of the Dispersion Hardened Silver-based Composite by Powder Metallurgy |
| EP4328933A1 (en) * | 2022-08-26 | 2024-02-28 | TE Connectivity Solutions GmbH | Coating on a surface to transmit electrical current |
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| CN1396025A (en) * | 2002-07-02 | 2003-02-12 | 华东师范大学 | Process for preparing electric silver/graphite contact material by nano technique |
| CN1713463A (en) * | 2004-06-21 | 2005-12-28 | 上海电器科学研究所（集团）有限公司 | Production of fibrous silver-graphite/silver contacts |
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| JPS52147768A (en) * | 1976-06-03 | 1977-12-08 | Sumitomo Electric Industries | Electric contact material |
| US4689196A (en) * | 1985-06-24 | 1987-08-25 | Gte Products Corporation | Silver-tungsten carbide-graphite electrical contact |
| JPS637345A (en) * | 1986-06-27 | 1988-01-13 | Sumitomo Electric Ind Ltd | Electrical contact material and its production |
| DE4111683A1 (en) | 1991-04-10 | 1992-10-22 | Duerrwaechter E Dr Doduco | MATERIAL FOR ELECTRICAL CONTACTS MADE OF SILVER WITH CARBON |
| DE19503184C1 (en) | 1995-02-01 | 1996-05-02 | Degussa | Ag-based material for electrical contacts with improved erosion characteristics and resistant to welding |
| US5831186A (en) * | 1996-04-01 | 1998-11-03 | Square D Company | Electrical contact for use in a circuit breaker and a method of manufacturing thereof |
| KR100415260B1 (en) * | 2001-07-31 | 2004-01-16 | (주)삼동 | Method for manufacturing non-oxygen Cu-Ag alloy |
| CN1256450C (en) * | 2003-06-04 | 2006-05-17 | 中国科学院金属研究所 | Silver-base electric contact head materials |
| JP2005120427A (en) * | 2003-10-16 | 2005-05-12 | Matsushita Electric Works Ltd | Material for electric contact, and electric contact |
| CN100365747C (en) * | 2003-12-23 | 2008-01-30 | 哈尔滨东大电工有限责任公司 | Electric contact material for low voltage electric appliance |
| CN1658346A (en) * | 2005-03-10 | 2005-08-24 | 上海大学 | Manufacturing method of silver-tungsten carbide-carbon electrical contact material |
| JP2007169701A (en) | 2005-12-21 | 2007-07-05 | Mitsubishi Material Cmi Kk | Material for electrical contact and its production method |
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2010
- 2010-03-03 JP JP2010526084A patent/JP4579348B1/en not_active Expired - Fee Related
- 2010-03-03 CN CN201080013341.2A patent/CN102362326B/en not_active Expired - Fee Related
- 2010-03-03 EP EP10755584.9A patent/EP2413337A4/en not_active Withdrawn
- 2010-03-03 CN CN201410043335.1A patent/CN103794385B/en not_active Expired - Fee Related
- 2010-03-03 WO PCT/JP2010/001444 patent/WO2010109777A1/en active Application Filing
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1396025A (en) * | 2002-07-02 | 2003-02-12 | 华东师范大学 | Process for preparing electric silver/graphite contact material by nano technique |
| CN1713463A (en) * | 2004-06-21 | 2005-12-28 | 上海电器科学研究所（集团）有限公司 | Production of fibrous silver-graphite/silver contacts |
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| Fabrication and properties of silver-matrix composites reinforced by carbon nanotubes;Yi Feng 等;《Materials Characterization》;20050930;第55卷(第3期);第212页左栏第2段，第215页图6，第216页左栏第2和3段 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102362326A (en) | 2012-02-22 |
| JP4579348B1 (en) | 2010-11-10 |
| EP2413337A1 (en) | 2012-02-01 |
| WO2010109777A1 (en) | 2010-09-30 |
| CN103794385A (en) | 2014-05-14 |
| CN103794385B (en) | 2016-03-30 |
| EP2413337A4 (en) | 2014-08-20 |
| JPWO2010109777A1 (en) | 2012-09-27 |
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