JP3827991B2 - Contact materials for vacuum circuit breakers - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention is particularly excellent in current cutting characteristics and withstand voltage characteristics while maintaining the breaking characteristics.Contact materials for vacuum circuit breakersAbout.
[0002]
[Prior art]
In addition to the three basic requirements represented by welding resistance, withstand voltage characteristics, and breaking (cut-off) characteristics, the contacts of vacuum valves used in vacuum circuit breakers have cutting (cutting) characteristics, wear resistance, and contact resistance. In order to maintain and improve the characteristics, temperature rise characteristics, etc., it is composed of various materials.
[0003]
However, since the above-mentioned required characteristics generally require material properties that are mutually contradictory, it is impossible to sufficiently satisfy with one element. Therefore, the development of contact materials suitable for specific applications such as high current interruption (cutoff) applications, high voltage resistance applications, low cutting (cuttering) applications through compounding of materials and material lamination, At present, it exhibits excellent characteristics.
[0004]
Cu-Bi alloy and Cu-Te alloy containing 5 wt% or less of anti-welding components such as Bi and Te as contact materials for large current interruption (severing) to satisfy the three basic requirements of general-purpose vacuum circuit breakers Are known (Japanese Patent Publication No. 41-12131, Japanese Patent Publication No. 44-23751).
[0005]
In Cu-Bi alloy, brittle Bi precipitated at grain boundaries, and in Cu-Te alloy, brittle Cu precipitated in grain boundaries and grains.₂Since Te embrittles the alloy itself and realizes a low welding pull-off force, it is also excellent in high current interruption (cutoff) characteristics. Of these alloys, a contact having Bi of, for example, about 10% by weight has an appropriate vapor pressure characteristic, and thus exhibits an excellent current cutting (cutting) characteristic (Japanese Patent Publication No. 35-14974).
[0006]
A Cu—Cr alloy is known as a contact material for high withstand voltage and large current interruption (severing) that satisfies the same three basic requirements. This alloy has the advantage that it can be expected to exhibit uniform performance with less vapor pressure difference between the constituents than the Cu-Bi alloy and Cu-Te alloy, and it is excellent depending on how it is used. is there.
[0007]
On the other hand, in recent years, vacuum circuit breakers aiming at high reliability and miniaturization need to further improve the current cutting (breaking) characteristics and withstand voltage characteristics (re-ignition characteristics) as described below. It has become.
[0008]
The first is that the vacuum valve contact that cuts off (or cuts off) current (or opens and closes) in high vacuum using the arc diffusibility in vacuum has two fixed and movable contacts facing each other. It is composed of When a vacuum valve is used in an inductive circuit such as a motor load without sufficient consideration to cut off (cut off) a small current, a transient abnormal surge voltage may be generated, which may affect the insulation of the load device.
[0009]
The cause of this abnormal surge voltage is the cutting phenomenon that occurs on the small current side when a small current is interrupted (cut off) in a vacuum (the current is forced without waiting for the natural zero point of the AC current waveform). This is due to the fact that it is interrupted) or a high-frequency arc extinction phenomenon. The abnormal surge voltage value Vs is proportional to the surge impedance Zo of the circuit and the cutting (cutting) current value Ic. Therefore, it is necessary to reduce the current cutting value Ic as one means for suppressing the abnormal surge voltage value Vs low. Ag-WC alloys are utilized as one of the beneficial contact alloys for this requirement.
[0010]
As a contact material for this low cutting (cutting), an Ag-WC alloy (Ag) that exhibits excellent low cutting (cutting) cutting ability by a synergistic action of the thermoelectron emission effect of WC and an appropriate vapor pressure of Ag. Is 40%) (Japanese Patent Application No. 42-68447).
[0011]
In addition, it is suggested that the use of a contact material in which the particle diameter of the arc-resistant component material (for example, the particle size of WC) is 0.2 to 1 μm is effective in improving the cutting (cutting) current characteristics ( JP-B-5-61338).
[0012]
Furthermore, by using a contact material with a WC-Co inter-particle distance of 0.3 to 3 μm, the arc cathode spot has good mobility (easiness to move), improving the high current interruption (cutoff) characteristics. A measured contact material is also known (Japanese Patent Laid-Open No. 4-206121).
[0013]
Second, the vacuum circuit breaker may induce a phenomenon in which a flash occurs in the vacuum valve after the current is interrupted (cut off), and the contacts are brought into conduction again (the discharge does not continue thereafter). This phenomenon is called re-ignition, and the mechanism of its occurrence is still unclear, but abnormal overvoltage is likely to occur because the electrical circuit suddenly changes to a conductive state after the current circuit is once cut off. .
[0014]
Even with a circuit breaker equipped with Ag-WC alloy, which is preferable as a current interruption (cutoff) characteristic, it was observed that an extremely large overvoltage and an excessively high frequency current were generated according to an experiment in which a capacitor bank was interrupted and re-ignited. Therefore, there is a demand for the development of a technique that suppresses the occurrence of re-ignition with respect to the Ag-WC alloy.
[0015]
The mechanism of occurrence of the re-ignition phenomenon of the Ag-WC alloy is not yet known, but according to the experimental observation by the present inventors, re-ignition is performed between the contacts / contacts in the vacuum valve and between the contacts / arc shield. It occurs quite frequently. Therefore, the present inventors have clarified techniques that are extremely effective in suppressing the occurrence of re-ignition, such as a technique for suppressing sudden gas released when a contact is subjected to an arc, and a technique for optimizing the contact surface form. Contributed to the suppression of reignition occurrence.
[0016]
That is, paying attention to the total amount of gas released in the heating process of the Ag-WC alloy, the type of gas, and the release form, and in detail observing the correlation with the occurrence of re-ignition, in the very short time near the melting point However, it was found that the rate of re-ignition increases at the contact point where a lot of gas is suddenly released in a pulsed manner.
[0017]
Therefore, the cause of sudden gas release in the Ag-WC alloy, such as heating at a temperature higher than the melting temperature of Ag, is removed in advance, and pores and structural segregation in the alloy of the Ag-WC alloy are suppressed. In this way, the re-ignition phenomenon has been greatly reduced by improving the sintering technology.
[0018]
However, in response to the demand for further suppression of re-ignition in recent years, the need for improvement is still recognized, and the development of other measures has become important. In recent years, as the trend of use has become severe, such as the expansion of adaptation to reactor circuits, capacitor circuits, etc., the load has been diversified, and in contrast to low-cutting (cutting) Ag-WC alloys In addition, there is an increasing demand for both lower cutting (cuttering) and lower re-ignitability, and the development and improvement of contact materials associated therewith is an urgent need. In the capacitor circuit, the voltage twice or three times the normal voltage is applied. Therefore, when the current is cut (cut off), the contact surface is significantly damaged by the arc at the time of current switching, resulting in rough contact and dropout wear. Invited, it is considered that this is one of the causes of re-ignition, so it is necessary to reduce contact wear.
[0019]
However, despite the fact that the re-ignition phenomenon is important from the viewpoint of improving the reliability of the product, the prevention technology is still not clear, and the direct cause of the phenomenon has not been clarified.
[0020]
[Problems to be solved by the invention]
As the low-cut (cutter) type contact material, the Ag-WC alloy has been applied in preference to the Cu-Bi alloy, Cu-Te alloy and Cu-Cr alloy described above. It has become a reality that the contact material is not a sufficient contact material for the demands for the reduction in the temperature and the low re-ignition, and it has been demanded to make both characteristics more highly compatible.
[0021]
That is, even in the case of an Ag-WC alloy that has been preferentially used as a low-cutting (contacting) type contact material so far, in a circuit with a more severe high voltage region and inrush current, the re-ignition phenomenon is still caused. Development has been observed. Therefore, it is desired to develop a contact material that achieves both low cutting (cutting) properties and re-ignition characteristics while maintaining the above three basic requirements at a certain level.
[0022]
  Therefore, the object of the present invention has been made in view of the above circumstances, and it is possible to combine current cutting characteristics and re-ignition characteristics that surpass the characteristics of conventional Ag-WC contact materials.Contact materials for vacuum circuit breakersThe purpose is to provide.
[0023]
[Means for Solving the Problems]
  According to the present inventionFor vacuum circuit breakerContact material is
  An arc-resistant component composed of 30 to 80% by mass of TiC;Cu or / and Ag as the balanceContaining a conductive component consisting ofContact materials for vacuum circuit breakersIn
  The region of the conductive component isDottedIt is composed of a plurality of conductive component phases, and the conductive component phases are formed of conductive component particles or aggregates thereof, and among the plurality of conductive component phases, 0.0001 to 0.01 mm.²Conductive component phase having a cross-sectional area of 5 to 65% by areaAnd 0.0001 to 0.01 mm ² The thickness of the conductive component phase having a cross-sectional area of 1 to 50 μmIt is characterized by that.
[0024]
With this contact material, it is possible to achieve both cutting characteristics and re-ignition characteristics.
[0025]
  That is, according to the present invention, the amount of the total conductive component (a) in the alloy is 20 to 70.mass%, It exhibits a remarkable effect when applied to an alloy containing at least one of Cu and Ag and TiC. The amount of all conductive components (a) is 20massIf it is less than%, sufficient shut-off characteristics cannot be obtained, and temperature rise characteristics also deteriorate. The amount of total conductive component (a) is 70massIf the percentage exceeds 50%, the re-ignition characteristic is degraded.
[0026]
  The present invention also provides:Consists of multiple conductive component phasesIn all conductive component region (a), PlaceThe conductive component phase (b) having a constant cross-sectional area is scattered (non-uniformly dispersed).
[0027]
The presence of the conductive component phase (b) having a size close to the upper limit has an effect of suppressing the appearance of a high contact resistance value. The presence of the conductive component phase (b) having a size close to the lower limit has an effect of suppressing the appearance of a high current cutting (cutting) value. Here, the conductive component phase (b) having a predetermined cross-sectional area is one conductive component particle or a region of fine conductive component particles, a cluster of fine conductive component particles, and an aggregate of fine conductive component particles. Etc., the cross-sectional area is 0.0001-0.01 mm²The main purpose is to control within the range.
[0028]
The conductive component phase (b) having the above cross-sectional area may be composed of the cross-sectional area of the raw material particles, or may be composed of an aggregate of minute conductive component phases (b). The main point is that a plurality of conductive component phases (b) having this cross-sectional area are scattered (non-uniformly dispersed) on the contact surface of the contact.
[0029]
Since a part of the conductive component phase (b) is scattered on the contact surface (contact surface), measurement is possible, but most of the conductive component phase (b) is embedded in the conductive component region and is three-dimensional. It is difficult to measure internal particles from the contact surface because it exists in a shape. Therefore, in the present invention, the area of a two-dimensional particle existing on an arbitrary plane, for example, a contact surface, is measured to obtain a cross-sectional area of the conductive component phase (b).
[0030]
In the present invention, the cross-sectional area of the conductive component phase (b) is 0.0001 to 0.01 mm.²However, the cross-sectional area of the conductive component phase (b) is 0.0001 mm.²If it is less than or too small, this conductive component phase (b) will be more finely distributed in the metal structure, and as a result, a structure that exists uniformly between the particles in the arc-resistant component region will be formed. A continuous arc-resistant component phase is not formed, and when it is cut off, a phenomenon that non-continuous arc-resistant component particles fall off is observed, which is not preferable because it induces re-ignition.
[0031]
On the other hand, the cross-sectional area of the conductive component phase (b) is 0.01 mm.²If it is too large so as to exceed, the coarse conductive component phases (b) between the opposing contacts induce the occurrence of welding, which is not preferable.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0039]
Unlike the conventional contact material in which the contact alloy used in the present invention uniformly disperses the fine conductive component phase (b) and the arc-proof component to suppress the decrease, the conductive component phase (b) is predetermined. It is a contact material dispersed non-uniformly in the range of.
[0040]
Conventionally, Ag-WC alloys are often used as contacts that exhibit stable low cutting characteristics. However, even this Ag-WC contact is not sufficient and requires further improvement for the requirement of simultaneously satisfying the cutting characteristics and the re-ignition characteristics. In recent breakers, it is an important requirement to set both characteristics to lower values, to maintain the low values even after opening and closing a predetermined number of times, and to reduce the variation width. Yes.
[0041]
The contact containing at least one of Cu and Ag of the present invention and TiC can be applied to products regardless of the presence or absence of an external magnetic field (for example, longitudinal magnetic field technology), but to block a larger current. For example, when an external magnetic field (for example, longitudinal magnetic field technology) is applied to cut off a large current (I), the arc generated by the interruption is prevented from staying and concentrating on a certain place and moving on the contact electrode surface. To do. This maintains the low cutting characteristics and contributes to a reduction in the rate of re-ignition. That is, since the arc easily moves on the contact electrode, the diffusion of the arc is promoted, which leads to a substantial increase in the area of the contact electrode that handles the breaking current, and the stagnation and concentration of the arc are reduced. The benefits of the prevention of local abnormal evaporation phenomenon and the reduction of surface roughness are also obtained, contributing to the suppression of re-ignition.
[0042]
However, when a large current value (Ia) exceeding a certain value (I) is interrupted, the arc stagnate at one or more places where it cannot be predicted, and that portion is abnormally melted to reach the interrupt limit. In addition, this abnormal melting generates excess metal vapor by instantaneous explosive evaporation of contact materials containing at least one of Cu and Ag and TiC, and insulation of the vacuum circuit breaker in the process of opening the electrode. Recoverability is significantly hindered, resulting in further deterioration of the cutoff limit characteristic. Furthermore, this abnormal melting is not preferable because it forms a huge droplet and causes the contact electrode surface to become rough, resulting in a decrease in withstand voltage characteristics, an increase in the rate of re-ignition, and abnormal consumption of the material. As described above, it is impossible to predict at which position on the contact electrode surface the arc that causes these phenomena will stay. It is desirable to give.
[0043]
In the present invention, after using a contact containing at least one of Cu and Ag and TiC, 0.0001 to 0.01 mm in the entire conductive component region (a) of the metal structure.²A plurality of conductive component phases (b) having a cross-sectional area in the range of 2 are interspersed to stabilize the cutting characteristics and the re-ignition characteristics.
[0044]
That is, in this invention, the presence of the conductive component phase (b) having a cross-sectional area close to the upper limit has an effect of suppressing the appearance of a high contact resistance value. The presence of the conductive component phase (b) having a cross-sectional area close to the lower limit has an effect of suppressing the appearance of a high current cutting (cutting) value.
[0045]
The cross-sectional area of the conductive component phase (b) is 0.0001 mm²If it is too small such as less than this, this conductive component phase (b) will be more finely distributed in the metal structure, resulting in the formation of a structure that exists uniformly between the particles in the arc-resistant component region. Therefore, a continuous arc-proof component phase is not formed, and when interrupted, a phenomenon that non-continuous arc-proof component particles fall off is observed, which is not preferable because it induces re-ignition.
[0046]
On the other hand, the cross-sectional area of the conductive component phase (b) is 0.01 mm.²If it is too large so as to exceed, the coarse conductive component phases (b) between the opposing contacts induce the occurrence of welding, which is not preferable.
[0047]
The cross-sectional area of the conductive component phase (b) which is the gist of the present invention is 0.0001 to 0.01 mm.²In addition to being an alloy containing at least one of Cu and Ag, and TiC, the amount of TiC and C (carbon) is optimized (evaporation is selectively given priority when subjected to an arc) Controlling to reduce the amount of Cu (or Ag) scattered is further beneficial for achieving both the desired cutting characteristics and the re-ignition characteristics.
[0048]
The cross-sectional area of the conductive component phase (b) which is the gist of the present invention is 0.0001 to 0.01 mm.²In addition to being an alloy containing at least one of Cu and Ag and TiC, systematic improvement of Cu (or Ag) and TiC in the contact material (the size of C and the presence of C) (Optimization of form) is further beneficial for achieving both desired cutting characteristics and re-ignition characteristics.
[0049]
The cross-sectional area of the conductive component phase (b) which is the gist of the present invention is 0.0001 to 0.01 mm.²In addition to the alloy containing at least one of Cu and Ag and TiC, the adhesion strength between TiC particles and C particles is improved (the contact surface is also affected by thermal shock during arcing). The occurrence of significant cracking that is harmful to the occurrence of re-ignition is also suppressed, and the scattering of TiC particles is also reduced), which is further beneficial for achieving both desired cutting characteristics and re-ignition characteristics.
[0050]
  The cross-sectional area of the conductive component phase (b) which is the gist of the present invention is 0.0001 to 0.01 mm.²In addition to the alloy containing at least one of Cu and Ag, and TiC, the C amount in a non-solid solution state or a compound non-formation state is 0.005 to 0 with respect to the TiC amount. .5massIt is more beneficial to achieve both the desired cutting characteristics and re-igniting characteristics by optimizing the amount as a percentage and limiting the size to 0.01-5 μm or less (diameter when converted to a sphere). is there.
[0051]
As described above, by optimizing the amount and size of C in the alloy containing at least one of Cu and Ag and TiC, Cu (or Ag), TiC, Uniform distribution of C, improvement of mutual adhesion strength of Cu (or Ag), TiC, C, etc., so huge melting traces, scattering damage, etc. that are harmful to re-ignition generation even after receiving an arc In addition, the contact surface roughness, which has an important effect on suppressing re-ignition, is reduced, which is beneficial for improving arc wear resistance. Improvement in arc wear resistance brings about smoothing of the contact surface, which is useful for reducing the variation width of the cutting characteristics and re-ignition characteristics even after many opening and closing. By these synergistic effects, the cutting characteristics were improved, and at the same time, the re-ignition occurrence frequency of the alloy containing at least one of Cu and Ag and TiC was suppressed and the wear resistance was improved.
[0052]
When the amount and size of C (non-solid solution or compound non-formation state) in the alloy containing at least one of Cu and Ag and TiC is excessive, the reignition occurrence rate increases ( Tend to deteriorate).
[0053]
Examples of the present invention will be described in detail below. The evaluation conditions are shown in FIGS. 1 to 3, the evaluation results are shown in FIGS. 4 to 6, and the evaluation criteria for cutting current characteristics, the determination criteria for re-ignition occurrence frequency, and the determination criteria for interruption characteristics are shown in FIGS. Indicated. The technology of the present invention is applied to a material configuration of a contact containing at least one of Cu and Ag and TiC.
[0054]
(1) Cutting characteristics
A predetermined contact having a diameter of 20 mm and a thickness of 4 mm, one of which is a plane and the other of which is 50 mmR, is attached to a detachable cutting current test vacuum interrupter. 10^-3After evacuating to Pa or lower and cleaning the contact surface by baking, discharge aging, etc., the device was opened at a rate of 0.8 m / sec. The cutting current value was obtained by observing the voltage drop of the coaxial shunt inserted in series with the contact when the circuit current of 50 Hz and the effective value of 40 A was interrupted 20,000 times. Therefore, the number of times of opening and closing is shown separately in the initial period (from 1 to 100 times) and the number of times of opening and closing is in the latter period (19,900 times to 20,000 times).
[0055]
Further, the measurement result is a relative value with respect to the maximum value of the cutting current value of Example 1 being 1.0. It can be said that this cutting value has a superior cutting characteristic as the value is smaller and the variation range is smaller.
[0056]
The evaluation criteria for the cutting current characteristics were as follows. That is, as shown in FIG. 7, when the maximum value of opening and closing 1 to 100 times of Example 1 is Ic, the magnification is evaluated as less than 0.7 times (A), 0.7 to 0.85 times Less than (B1), 0.85 or more to <Ic is evaluated (B2),> Ic to less than 1.3 times (C1), 1.3 to less than 1.5 times (C2), 1.5 to less than 2.5 times was evaluated as (X), 2.5 to less than 3.5 times was evaluated as (Y), and 3.5 times or more was evaluated as (Z). In addition, the range of (A)-(C2) was made into the standard of (pass), and the range of (X)-(Z) was made into the standard of (failure).
[0057]
(2) Re-ignition characteristics
FIGS. 4 to 6 show the frequency of re-ignition when a disk-shaped contact having a diameter of 30 mm and a thickness of 5 mm is mounted on a demountable vacuum valve and a 6 kv × 500 A circuit is cut off 2,000 times. When attaching the contacts, only baking heating (450 ° C. × 30 minutes) was performed, and the brazing material was not used and the heating associated therewith was not performed. The measurement results are comparative values when the number of reignition occurrences in Example 1 is 1.0. It can be said that the re-ignition occurrence frequency has better re-ignition characteristics as the value is smaller and the variation range is smaller.
[0058]
The criteria for determining the re-ignition frequency are as follows. That is, as shown in FIG. 8, the relative magnification when the number of re-ignition occurrences of Example 1 is 1.0 is evaluated as less than 0.1 times (A), and 0.1 to 0.8 times. Evaluation (B), 0.8 to 1.2 times evaluated (C), 1.2 to 1.5 times evaluated (D), 1.5 to 10 times evaluated (X), 10 or more ˜100 times was evaluated as (Y), and 100 times or more was evaluated as (Z). In addition, the range of (A)-(D) was made into the standard of (pass), and the range of (X)-(Z) was made into the standard of (failure).
[0059]
(3) Interrupting characteristics
The current value when the circuit of 24 kv and 50 Hz was successfully cut off without re-ignition was determined to be pass or fail based on the relative value when Example 1 was set to 1.0. The measurement result is a comparison value when the current value when the interruption in Example 1 is successful is 1.0.
[0060]
The criteria for judging the cutoff characteristics were as follows. That is, as shown in FIG. 9, the case where the relative magnification is 130% or more when the blocking characteristic of Example 1 is 1.0 is evaluated (S), and the case where the relative magnification is 130% to 115% or more is evaluated (A). 115% to 105% or more evaluated (B), 105% to 95% or more evaluated (C), 95% to 85% or more evaluated (X), 85% to 50% or more The case was evaluated (Y), and the case of 50% or less was evaluated (Z). In addition, the range of (S)-(C) was made into the standard of (pass), and the range of (X)-(Z) was made into the standard of (failure).
[0061]
(4) Other characteristics
The following evaluations were supplemented for some required samples.
[0062]
Contact resistance characteristics: A pure Cu rod electrode with a radius of curvature of 5R and a flat sample electrode are opposed to each other, a contact load of 10 kg is applied between them, and a direct current of 10 A is energized to obtain a contact resistance from the potential drop between the two. It was.
[0063]
(5) Examples of contact manufacturing methods
For manufacturing the contact of the present invention, the following manufacturing methods can be appropriately selected. In the following description, the case where Cu is used as the conductive component is described. However, even when a part or all of the conductive component is replaced with Ag, the same can be performed as appropriate.
[0064]
As an example of a method for producing this contact material, an infiltration method in which Cu is dissolved and poured into a void of a (TiC) skeleton, and (TiC, Cu) powder obtained by mixing TiC and Cu powder at a predetermined ratio is sintered or It is possible to employ a sintering method for molding and sintering.
[0065]
According to such a manufacturing method example, the cross-sectional area of the conductive component phase (b) in the alloy of the contact material is stably 0.0001 to 0.01 mm.²Can be controlled within the range.
[0066]
(Production Example 1-1)
One example of a method for producing this contact material is a very fine and very small amount of Cu (fine Cu) extracted from a part of the amount of the conductive component region (a) that is finally required, and finally The first [TiC, Cu] mixed powder is obtained by mixing with a very small amount of TiC extracted from a part of the amount of TiC required for the above (repeating this until the nth mixing if necessary). This primary mixed powder (or nth mixed powder) and the remainder of the TiC powder are mixed while adjusting to the target component to obtain the final [TiC, Cu] mixed powder. This final [TiC, Cu] powder is used as it is or, for example, 8 ton / cm.²For example, after solid-phase sintering (or a combination of solid-phase sintering and molding once or multiple times) at a sintering temperature of 930 ° C. to form a Cu—TiC contact material, Process into a predetermined shape to make a contact.
[0067]
(Production Example 1-2)
Another example of the production of this contact material is Cu (if necessary, Bi as an auxiliary component) in the void of [TiC, Cu] skeleton having a predetermined porosity obtained by solid-phase sintering the [TiC, Cu] powder. Is added at, for example, an infiltration temperature of 1150 ° C., and a Cu—TiC contact material is processed into a predetermined shape to form a contact. In the mixing step, if necessary, at least one of Bi, Sb, and Te may be added, and if necessary, at least one of Cr, Fe, Co, and Ni may be added.
[0068]
(Production Example 1-3)
Another example of production of this contact material is that an extremely fine and very small amount of Cu taken out from a part of the finally required amount of Cu and Cr powder as an auxiliary component (preferably approximate volume). To obtain a primary [Cu, Cr] mixed powder obtained by mixing (if necessary, repeat this until the n-th mixing). This primary mixed powder (or nth mixed powder) and the remaining Cu powder are mixed again to finally obtain [Cu, Cr] powder in a sufficiently good mixed state. After mixing the [Cu, Cr] powder and a predetermined TiC powder (finally required TiC amount), sintering and pressurization at a temperature of 950 ° C., for example, in a hydrogen atmosphere (even in a vacuum) A Cu-TiC contact material was produced by combining once or multiple times.
[0069]
(Production Example 1-4)
Another example of manufacturing this contact material is Cu (add Bi if necessary) in the [TiC, Cr] skeleton void having a predetermined porosity obtained by solid-phase sintering the [TiC, Cr] powder. Is infiltrated at a temperature of 1150 ° C., for example, and processed into a predetermined shape as a Cu—TiC contact material to form a contact (a small amount of Cr).
[0070]
In a [TiC, Cu, Cr] skeleton void having a predetermined porosity obtained by solid phase sintering of [TiC, Cu, Cr] powder, Cu (add Bi if necessary) at a temperature of, for example, 1150 ° C Infiltrated and processed into a predetermined shape as a Cu—TiC contact material to form a contact (a small amount of Cr). The same applies to a predetermined amount of Co, Ni, and Fe instead of Cr.
[0071]
(Production Example 2-1)
In the present invention, 0.0001 to 0.01 mm in the conductive component region (a) in the Cu-TiC-based contact constituted by the arc-resistant component region and the conductive component region (a).²The point is how the conductive component phase (b) having the following cross-sectional area exists.
[0072]
That is, as one example of making this conductive component phase (b) exist in the conductive component region (a), in the conductive component region (a) when producing the [TiC, Cu] mixed powder, When a high substance such as paraffin is mixed and volatilized and removed during sintering, voids remain in the conductive component region (a). These holes are used as the conductive component phase (b) during infiltration.
[0073]
(Production Example 2-2)
In addition, when a fine carbon powder is mixed instead of the paraffin in the conductive component region (a) when the [TiC, Cu] mixed powder is produced, and this is volatilized and removed during sintering ( a) The vacancies remaining in it can also be used in the infiltration. Even if other volatile substances that are volatilized and removed below the sintering temperature are employed, they can be manufactured in the same manner.
[0074]
In the examples of the present invention, the methods of Production Example 1 and Production Example 2 as described above are appropriately selected and employed alone or in combination. A contact material that exhibits the effects of the present invention can be obtained by selecting either technique. Can be obtained.
[0075]
In the case of Cu-VC in which a predetermined amount of VC (vanadium carbide) having a predetermined particle diameter is selected as a part or all of TiC (titanium carbide) as an arc-resistant component, the same manufacturing method as described above can be selected. Also, the sintering temperature and the infiltration temperature can be appropriately selected.
[0076]
  (Examples 1-2, Comparative Examples 1-2)
  As a contact material, the size of the cross-sectional area of the conductive component phase (b) existing in the entire conductive component region (a) is 0.0001 mm.²Less than and 0.0001-0.3mm²45mass% Cu—TiC alloy was prepared (Examples 1-2, Comparative Examples 1-2). The ratio between the amount of C and the amount of TiC in a non-solid solution state or a compound non-formation state was 0.01 by composition analysis and microstructural observation from the prototype contact material.mass% Alloy was selected.
[0077]
These materials are processed into a predetermined shape having a thickness of 4 mm and an average surface roughness of 0.3 μm as a test piece, and cutting characteristics, re-ignition characteristics, and interruption characteristics are measured. The standard was compared. The contents are shown in FIG. 1 (evaluation conditions) and FIG. 4 (results).
[0078]
  The amount of the total conductive component region (a) in the contact material is 45massIn a Cu-TiC alloy having a constant%, the size of the cross-sectional area of the conductive component phase (b) existing in the entire conductive component region (a) is 0.0001 mm.²Less than and 0.0001-0.3mm²As a result, the cross-sectional area of the conductive component phase (b) was set to 0.0001 to 0.01 mm.²In this range, all of the cutting characteristics, the re-igniting characteristics, and the cutoff characteristics are exhibiting good characteristics (Examples 1 and 2).
[0079]
On the other hand, the value of the cross-sectional area of the conductive component phase (b) is 0.0001 mm.²The cutting characteristics were evaluated as B1 to B2, and the blocking characteristics were evaluated as B to C, and the characteristics were extremely good as compared with Example 1 which is standard. However, the re-ignition characteristic shows evaluations C to Y, which shows a large variation compared to the standard example 1, which is not preferable (Comparative Example 1).
[0080]
Furthermore, the value of the cross-sectional area of the conductive component phase (b) is 0.03 mm.²In the meantime, the evaluation of the cutting characteristics is the same as the standard example 1 in the average value in the initial period of opening and closing (1 to 100 times opening and closing) and in the latter period of opening and closing (19,900 to 20,000 times opening and closing). Although there was no problem with the characteristics of the degree (evaluation C1 to C2), the characteristic deterioration (evaluation X, Y) was shown at the maximum value, which was not preferable (Comparative Example 2).
[0081]
Thus, the cross-sectional area of the conductive component phase (b) is 0.0001 mm.²When it is less than that, the conductive component phase (b) is dispersed in an excessively fine metal structure, and as a result, a uniform structure is formed between the particles of the arc-resistant component powder, so that the contact resistance characteristics are stabilized. This is not preferable because it contributes less.
[0082]
On the other hand, when the cross-sectional area of the conductive component phase (b) exceeds 0.01, the occurrence of welding due to contact between coarse conductive components on the contact surfaces facing each other can be seen, and this may cause re-ignition phenomenon. Absent.
[0083]
  (Examples 3-4, Comparative Examples 3-4)
  As a contact material, the size of the cross-sectional area of the conductive component phase (b) existing in the entire conductive component region (a) is 0.0001 to 0.01 mm.²And the total conductive component region (a) is 20 to 70.mass%, All the cutting characteristics, re-igniting characteristics, and interruption characteristics are exhibiting good characteristics (Examples 3 to 4).
[0084]
  10 for all conductive component regions (a)massWhen the same evaluation was performed on the Cu-TiC alloy having the remaining TiC (comparative example 3), the re-ignition characteristic was in the same preferable range (evaluation B) as compared with the standard example 1. ~ C).
[0085]
However, when the cutting characteristics were evaluated, in the initial opening and closing (1 to 100 times opening and closing) range, the characteristics were extremely good (evaluation A to B2) compared to the standard example 1, It is not preferable because the characteristic deteriorates (evaluation Y) at the maximum value of the cutting current value in the later stage of switching (19,900 to 20,000 times during switching).
[0086]
Further, in the blocking characteristics, a significant decrease (evaluation X to Y) and variations were observed.
That is, when compared with the cutoff current value of Example 1 which is a comparison target, the current value of successful cutoff in Comparative Example 1 is not preferable because it is reduced to 50 to 95%.
[0087]
  On the other hand, the total conductive component region (a) is 85%.massWhen the same evaluation was performed on the Cu-TiC alloy having the remaining TiC (comparative example 4), the barrier property was significantly improved compared to the standard example 1 (evaluation A to A). B)
[0088]
However, when the cutting characteristic evaluation was performed, a large gap was observed between the average value and the maximum value (evaluation C2 to Y), and particularly in the latter period of opening and closing, a significant decrease and a large variation (evaluation X to Z) were exhibited. .
[0089]
Moreover, compared with Example 1 which also makes the re-ignition characteristic standard, it showed a large variation (evaluation C to X), which was not preferable.
[0090]
  Total conductive component area (a) is 10mass% (Comparative Example 3), a significant decrease in the electrical conductivity of the material and an increase in the contact resistance were observed, and the interruption characteristics were significantly decreased.
[0091]
  Total conductive component area (a) is 85massIn the case of% (Comparative Example 4), due to the decrease in arc resistance, abnormal firing of the contact surface after interruption caused frequent re-ignition and decreased cutting characteristics.
[0092]
In Comparative Example 4, according to the result of microscopic observation of the contact surface after measurement, the contact surface was found to be dotted with Cu absent portions, aggregated TiC, and dropped TiC.
[0093]
  Therefore, in order to obtain a balance between the re-ignition characteristic, the cutting characteristic, and the cutoff characteristic, the total conductive component region (a) shown in Examples 3 to 4 is 20 to 70.mass% Cu-TiC alloy is effectively used when the present invention technique is applied.
[0094]
  That is, Cu as the total conductive component (a) is 20 to 70.mass%, As a correlation, TiC as an arc-proof component has a high density portion as viewed microscopically, and due to the high density area, the withstand voltage characteristics of the entire contact as a circuit breaker, This is effective for improving re-ignition characteristics and maintaining low cutting characteristics.
[0095]
  In this case, the amount of Cu as the total conductive component (a) is 20massWhen it is less than%, the basic function as a contact material is lowered due to a decrease in conductivity and an increase in contact resistance. The amount of Cu as the total conductive component (a) is 70massWhen the percentage exceeds 50%, the contact surface cannot obtain a sufficient temperature due to high thermal conductivity, and the thermal electron emission from TiC cannot be obtained sufficiently, making it difficult to maintain low cutting characteristics and causing reignition. Is also undesirable.
[0096]
  In addition, TiC as an arc resistant component is a component that is excellent in arc resistance and welding resistance and is also involved in the long life of the contact.mass% Content is preferred.
[0097]
  The content of TiC as an arc resistant component is 30massWhen it is less than%, thermionic emission from TiC cannot be obtained sufficiently, and it is difficult to maintain the low cutting characteristics, and it is difficult to extend the contact life. The content of TiC as an arc resistant component is 80massWhen the percentage exceeds 50%, the above-mentioned conductive amount is relatively lowered, and the basic functions as a contact material such as a lowered energization function of the contact are lowered by a decrease in conductivity and an increase in contact resistance.
[0098]
(Examples 5-6, Comparative Examples 5-6)
In Examples 3 to 4 and Comparative Examples 3 to 4, 0.0001 to 0.01 (mm) occupied in the entire conductive component region (a).²) In the case where the ratio of the conductive component phase (b) having a cross-sectional area of 25 to 35 area% is shown, it has an influence on the cutting characteristics, the re-ignition characteristics, and the cutoff characteristics. The effect is exhibited not only in the case of 35 area%. That is, the ratio of the conductive component phase (b) in the total conductive component region (a) is 5 to 15 area% (Example 5) and 50 to 65 area% (Example 6). Compared with Example 1, the same preferable characteristics were exhibited.
[0099]
However, when the proportion of the conductive component phase (b) in the total conductive component region (a) is less than 5 area% (Comparative Example 5), the cutting characteristics are good, showing evaluations B2, C1, and C2. The arc characteristics were also good with evaluations B to C, but they were not preferable because they showed a decrease in the interruption characteristics and large variations (evaluations C to Y).
[0100]
Further, when the ratio of the conductive component phase (b) in the total conductive component region (a) is 75 to 85 area% (Comparative Example 6), the cutting characteristics are good, indicating evaluations A, B1, and B2, and the blocking. Although the characteristics were good with evaluations A to B, the re-ignition characteristics were reduced and large variations were observed (evaluations D to X), which is not preferable.
[0101]
Thus, the cross-sectional area is 0.0001 to 0.01 mm at 5 to 65 area% with respect to the content of all conductive components (a).²By providing a plurality of conductive component phases (b) in a scattered manner, it is possible to suppress re-ignition as a contact material while maintaining low cutting characteristics.
[0102]
When the conductive component phase (b) is less than 5% by area with respect to the total content of the conductive component (a), the cross-sectional area is 0.0001 mm.²As in the case of less than 5, the Cu (conductive component phase (b)) is relatively finely present between the TiC particles (arc-resistant component region), and stable contact is a basic requirement as a circuit breaker. It becomes difficult to obtain resistance characteristics (to reduce the variation width of the contact resistance value), which is not preferable.
[0103]
On the other hand, if it exceeds 65 area%, the cross-sectional area is 0.01 mm.²As in the case of exceeding the range, coarse conductive components are often welded to the contact surfaces of the opposing contacts, and the occurrence of a re-ignition phenomenon is also undesirable.
[0104]
(Examples 7-8, Comparative Examples 7-8)
In the said Examples 3-6 and Comparative Examples 3-6, 0.0001-0.01mm which occupies in all the electroconductive component area | regions (a).²In the case where the thickness of the conductive component phase (b) having a cross-sectional area of 8 to 15 μm is shown, it has an influence on the cutting characteristics, the re-ignition characteristics, and the cutoff characteristics. In the present invention, the thickness is 8 to 15 μm. The effect is not limited to the case. That is, even when the thickness of the conductive component phase (b) in the total conductive component region (a) is 1 to 10 μm (Example 7) and 35 to 50 μm (Example 8), the standard example is used. Compared with 1, it showed the same preferable characteristics.
[0105]
However, when the thickness of the conductive component phase (b) in the total conductive component region (a) was less than 1 μm (Comparative Example 7), the interruption characteristics were good indicating evaluations A to C, but the latter period of opening and closing (19 , 900 to 20,000 times (opening and closing), the characteristic value degradation (evaluation X) is not preferable at the maximum cutting current value. Moreover, the re-ignition characteristic is lowered and large variation (evaluation C to X) is not preferable (Comparative Example 7). During the test of the re-ignition characteristics, TiC particles were dropped, the contact surface was deteriorated, and the deterioration of the re-ignition characteristics was affected (Comparative Example 7).
[0106]
Moreover, when the thickness of the conductive component phase (b) in the total conductive component region (a) was 70 to 110 μm, the cutting characteristics were evaluated as B1 to B2, and the cutoff characteristics were evaluated as A to B. However, the re-ignition characteristics show a decrease and large variation (evaluation C to X), which is not preferable (Comparative Example 8).
[0107]
That is, in this invention, 0.0001 to 0.01 mm²When the thickness of the conductive component phase (b) having the cross-sectional area is in the range of 1 to 50 μm, stable re-ignition characteristics are exhibited. When the thickness of the conductive component phase (b) is less than 1 μm, it is dropped at the time of interruption, and as a result, it is a cause of variation in re-ignition characteristics due to a change in the surface state. 0.0001mm²The conductive component phase (b) having a cross-sectional area exceeding 1 μm is selected in the range of 1 to 50 μm. The thickness is measured by polishing the conductive component portion (a) of the contact material to expose the cut surface. It can be measured by observing the surface with a metallographic microscope.
[0108]
  (Examples 9 to 10, Comparative Examples 9 to 10)
  In Examples 1 to 6 and Comparative Examples 1 to 6, the ratio between the amount of C in a non-solid solution state (or compound non-formation state) and the amount of TiC (mass%) 0.01massIn the present invention, the ratio of the amount of C in the non-solid solution state to the amount of TiC is 0.01.massThe effect is obtained without being limited to%. That is, the ratio between the C amount in the non-solid solution state and the TiC amount is 0.005 to 0.5.mass% (Examples 9 to 10) showed the same preferable characteristics as those of Example 1 as a standard.
[0109]
  On the other hand, the ratio of the C amount in the non-solid solution state to the TiC amount is 0.05.massLess than% (Comparative Example 9), the re-ignition characteristic and the breaking characteristic were good, indicating evaluations A to B, but the maximum value of the cutting characteristic, particularly in the late stage of opening and closing (during opening and closing 19,900 to 20,000 times). In this case, variation is observed, stable cutting characteristics cannot be obtained, and evaluation X is shown, which is not preferable.
[0110]
  Further, the ratio of the C amount in the non-solid solution state to the TiC amount is 0.5.massIn the case of 10% or more (Comparative Example 10), the cutting characteristics were good with evaluations B1 to B2 and evaluations B1 to C1, but the re-ignition characteristics showed a significant decrease (evaluation X to Y). In particular, there is a large variation (evaluation C to Z) in the cutoff characteristic, which is not preferable.
[0111]
  Thus, C in a non-solid solution state or a non-compound formation state is 0.005 to 0.5 with respect to the amount of TiC.mass% Is preferably present.
[0112]
  That is, in this invention, C exists as an auxiliary component. When the amount of C is increased, the current cutting characteristics are substantially improved, but the re-ignition characteristics are substantially deteriorated. In order to achieve both the current cutting characteristics (low cutting and stabilization) and the reduction of re-ignition phenomenon at the same time, the C existing in Cu-TiC is in a non-solid solution state. Alternatively, the compound is not formed, and the amount is 0.005 to 0.5 with respect to the TiC amount.massIt is preferable to manage in the range of%, and to manage the size existing in the contact in the range of 0.01 to 5 μm (diameter when converted to a sphere). Thus, the effect is obtained. Therefore, the average particle size and amount of C in the Cu—TiC-based contact material and the degree of dispersion are important points.
[0113]
  The amount of C present in Cu—TiC in a non-solid solution state or a compound non-formation state is 0.005 with respect to the TiC amount.massIf it is less than%, stable cutting characteristics cannot be obtained. On the other hand, the amount of C is 0.5% of the amount of TiC.massIf it exceeds 50%, the withstand voltage characteristic is lowered and the variation width is increased, which is not preferable.
[0114]
If the size of C in the non-solid solution state or compound non-formation state present in Cu-TiC is less than 0.01 μm (diameter when converted to a sphere), stable cutting characteristics cannot be obtained. On the other hand, if the size of C exceeds 5 μm (diameter when converted to a sphere), a decrease in the withstand voltage characteristics and an increase in the variation width are also undesirable.
[0115]
The optimization of the existence state and the amount of C (non-solid solution or compound non-formation state) in Cu-TiC alloy, which is one of the triggers of the re-ignition rate, is also the cutting characteristics and re-ignition characteristics. It is important to achieve both. Therefore, selection of the manufacturing method of the Cu-TiC alloy which influences the presence state of C in a Cu-TiC alloy is also important. That is, the preferred TiC powder in the practice of the present invention is, for example, by controlling the heat treatment temperature, time, atmosphere, etc., the amount of C in a non-solid solution state in TiC or the state in which no compound is formed with TiC. While adjusting the amount, particle size and particle size distribution, stoichiometrically (TiC₁~_0.7TiC in the range of) is selected.
[0116]
A very small amount of fine C (non-solid solution or compound non-formed state) exists in the Cu-TiC alloy. As a control technique for this extremely small amount of C, in addition to the above-described method of heat-treating TiC powder, for example, when certain organic substances are thermally decomposed together with TiC, C that is decomposed and deposited on the TiC surface is used. Can also be obtained. It can also be obtained by depositing a C sputtered film on the TiC surface and using it as a raw material TiC.
[0117]
If the amount and size of C (non-solid solution or compound non-formation state) in the Cu—TiC alloy is excessive, the re-ignition occurrence rate tends to increase (characteristic deterioration).
[0118]
(Example 11, Comparative Example 11)
In Examples 1 to 10 and Comparative Examples 1 to 10, the average dispersion interval (distance between particles) (x) of C particles dispersed in Cu—TiC and the size (diameter) of the nearest C particles (diameter) ( In the case of (x)> (d), the relationship with d) shows the influence on the cutting characteristics, the re-ignition characteristics, and the cutoff characteristics. In the present invention, the average dispersion interval (x) of C particles and The relationship with the size (d) of the closest C particle is not limited to when (x)> (d), and the effect is obtained. That is, even in the case of (x) = (d), the same preferable characteristics were shown as compared with the standard example 1 (example 11).
[0119]
On the other hand, when the relationship between the average dispersion interval (x) and the size (d) of the nearest C particle is (x) <(d) (Comparative Example 11), the cutting characteristics are evaluated B1 to B2. Although B1-C1 was shown and it was favorable, the fall of the interruption | blocking characteristic and the re-ignition characteristic and a big dispersion | variation were seen (evaluation XZ), and it is unpreferable. The fact that an excessive arc is concentrated on the portion C at the time of interruption works (Comparative Example 11).
[0120]
Thus, C in the non-solid solution state or the non-compound formation state is highly dispersed and distributed in the Cu-TiC alloy, and the interval between the C particles, that is, the distance between the C particles is the nearest C. It is preferable that the particle size is not less than the size of the particle, that is, not less than the diameter of the nearest C particle.
[0121]
That is, in the present invention, the distance between C particles in a non-solid solution state or a non-compound formation state dispersed in a Cu—TiC-based alloy, that is, the distance between C particles is larger than the size of the nearest C particle. If the diameter is smaller, that is, smaller than the diameter of the nearest C particle, the arc is excessively concentrated on the C portion at the time of interruption or the like.
[0122]
  (Examples 12 to 17, Comparative Example 12)
  In Examples 1 to 11 and Comparative Examples 1 to 11, as the auxiliary component (1) contained in Cu-TiC, the ratio of the Cr amount to the TiC amount was set to zero and 0.4.massIn the case of%, the influence on the cutting characteristics, the re-ignition characteristics, and the cutoff characteristics has been shown, but in the present invention, the auxiliary component (1) obtains the effects without being limited thereto. That is, even when the auxiliary component (1) was Co, Fe, or Ni, the same preferable characteristics were exhibited as compared with the standard example 1 (Examples 12 to 14).
[0123]
  Moreover, auxiliary component (1) is 0.05-2.massEven in the case of% Cr, the same preferable characteristics were shown as compared with the standard example 1 (Examples 15 to 17).
[0124]
  In contrast, the amount of Cr as the auxiliary component (1) is 8massIn the case of% (Comparative Example 12), the re-ignition characteristics showed evaluations C to D and passed, but in the cutting characteristics, evaluations B1 to B2 were evaluated in the initial stage of opening and closing (1 to 100 times). In the latter case (19,900 to 20,000 times), the evaluations B1 to X are shown and the variation is not preferable. Even in the cut-off characteristic, deterioration of the characteristic and large variation are observed (evaluation C to Y), which is not preferable.
[0125]
  Cr content is 8mass% 45massIn% TiC and the remaining Cu alloy (Comparative Example 12), the cutting current value increased significantly (characteristics deteriorated). Cr content is 8massIt was thought that this was due to the fact that the electrical conductivity of the alloy itself was improved due to the presence of 1%, and that the thermal electron emission ability of TiC itself was reduced.
[0126]
According to microscopic observation, a predetermined amount or more of Cr exists as excess Cr in the structure and tends to aggregate and coarsen C in the structure, and segregation of C increases the frequency of reignition. It was thought to be the cause.
[0127]
  Therefore, in order to obtain a balance between the re-ignition characteristic, the cutting characteristic, and the cutoff wear, the Cr amount 2 shown in Example 17 is 2massIn the Cu-TiC contact with the upper limit of% (including Cr zero as shown in Example 1), the technique of the present invention is effectively exhibited. The average particle diameter of Cr as the auxiliary component (1) is preferably 10 μm or less, and more preferably 0.1 to 5 μm.
[0128]
  Thus, as the auxiliary component (1), Cr having an average particle diameter of 10 μm or less is 2% with respect to the TiC amount.mass%, The diffusion of Cr to the surface of TiC particles advances, the wettability with the interface between Cu and TiC is improved, the oxygen content is suppressed, and the production of dense contact materials is enabled. This contributes to the stabilization of the cutoff characteristics.
[0129]
  The amount of the auxiliary component (1) made of Cr is 2 with respect to the TiC amount.massIf it exceeds 50%, the cutting properties are deteriorated, which is not preferable. On the other hand, when the average particle size of the auxiliary component exceeds 10 μm, the variation width is increased in the cutting characteristics, which is not preferable.
[0130]
Furthermore, even when at least one of Co, Fe, and Ni is used as the auxiliary component (1) instead of Cr, the technology of the present invention is effectively exhibited. Also in this case, the average particle diameter of the auxiliary component (1) is preferably 10 μm or less, and more preferably 0.1 to 5 μm.
[0131]
  Thus, as the auxiliary component (1), at least one of Co, Fe, and Ni having an average particle diameter of 10 μm or less is 2% with respect to the amount of TiC.mass% Or less, the diffusion of the auxiliary component (1) to the TiC particle surface proceeds, the wettability with the interface between Cu and TiC is improved, the oxygen content is suppressed, and the high density contact material It enables manufacturing and contributes to the stabilization of the interruption characteristics.
[0132]
  The amount of the auxiliary component (1) composed of at least one of Co, Fe, and Ni is 2 with respect to the TiC amount.massIf it exceeds 50%, the cutting properties are deteriorated, which is not preferable. On the other hand, when the average particle size of the auxiliary component exceeds 10 μm, the variation width is increased in the cutting characteristics, which is not preferable.
[0133]
(Examples 18 to 23, Comparative Examples 13 to 15)
In the said Examples 1-17 and Comparative Examples 1-12, about the case where the auxiliary component (2) as a welding prevention element contained in Cu-TiC is made into zero, it influences on a cutting characteristic, a re-ignition characteristic, and a interruption | blocking characteristic Although the influence was shown, the auxiliary component (2) in the present invention obtains its effect without being limited thereto. That is, in the case where the auxiliary component (2) is in a Bi amount within a predetermined amount, the same preferable characteristics were exhibited as compared with the standard Example 1 (Examples 18 to 19).
[0134]
  However, the ratio of Bi amount in Cu-TiC is 5massIn the case of%, the cutting characteristics were good indicating evaluations A to B2 and B2 to C1, but the re-igniting characteristics were not preferable indicating evaluations X to Z, and the interruption characteristics were greatly reduced (evaluation Z). Not preferable (Comparative Example 13).
[0135]
In addition, even when the auxiliary component (2) was Sb within a predetermined amount, the same preferable characteristics were exhibited as compared with the standard example 1 (Examples 20 to 21).
[0136]
  However, the ratio of the amount of Sb in Cu-TiC is 5massIn the case of%, the cutting characteristics were good with evaluations A to B2 and C1, but the re-ignition characteristics showed evaluations X to Z, which was not preferable, and particularly the interruption characteristics were greatly reduced (evaluation Z). No (Comparative Example 14).
[0137]
Further, even when the auxiliary component (2) was Te within a predetermined amount, the same preferable characteristics were exhibited as compared with the standard Example 1 (Examples 22 to 23).
[0138]
  However, the ratio of Te amount in Cu-TiC is 10massIn the case of%, the cutting characteristics were good indicating evaluations B1 to B2 and B2 to C1, but the re-igniting characteristics were not preferable indicating evaluations X to Z, and in particular, the interruption characteristics were greatly reduced (evaluation Z). Not preferred (Comparative Example 15).
[0139]
  Thus, as an auxiliary component (2) as an anti-welding element, at least one of Bi and Sb is added to the Cu—TiC alloy.mass% Or less, or Te in Cu-TiC alloy 5massThe effect can be acquired by containing% or less.
[0140]
  The amount of at least one of Bi and Sb is 1mass% Or the amount of Te is 5massIf it exceeds 50%, the withstand voltage characteristics and the re-ignition characteristics are undesirably deteriorated and the variation width is increased.
[0141]
(Examples 24-26, Comparative Examples 16-17)
In Examples 1 to 23 and Comparative Examples 1 to 15, when the average particle diameter of the arc resistant component (TiC particles) used in the production of the Cu—TiC alloy was 1.5 μm, the cutting characteristics, Although the influence on the ignition characteristics and the interruption characteristics was shown, the average particle diameter of the TiC particles used in the present invention is not limited to 1.5 μm, and the effect is obtained.
[0142]
That is, when the average particle diameter of the TiC particles is 0.1 to 0.6 μm (Example 24), 0.5 to 3.0 μm (Example 25), 6.0 to 9.0 μm (Example 26). However, the same preferable characteristics were shown as compared with the standard example 1.
[0143]
On the other hand, when the average particle diameter of the TiC particles is less than 0.1 μm (Comparative Example 16), the cutting characteristics showed evaluation B1 and stable preferable characteristics, but the re-ignition characteristics were evaluated B to X. This is not preferable because it shows a large variation, and the interruption characteristic also shows a large variation and a decrease (evaluation C to Z). Voids are likely to remain in the contacts, and the re-ignition characteristics and interruption characteristics are affected by the increase in the amount of residual gas.
[0144]
Further, when the average particle diameter of the TiC particles is 15.0 μm or more (Comparative Example 17), in the cutting characteristics, the opening / closing initial stage (1 to 100 times) and the opening / closing late stage (19,900 to 20,000 times). In both cases, the average values are evaluation B2 and evaluation C1, which are good, but the maximum values are evaluation X and evaluation Z. (Evaluation C to Y) is not preferable.
[0145]
Thus, it is preferable that the average particle diameter of TiC which comprises an arc-proof component area | region is 0.1-9 micrometers.
[0146]
That is, in the present invention, when the average particle diameter of TiC is less than 0.1 μm, the gas content is large, and an unhealthy contact material with many defects such as voids is obtained, and as a result, the cutting characteristics are stabilized. The interruption characteristics and re-ignition characteristics are reduced. On the other hand, when the average particle diameter of TiC exceeds 9 μm, there are variations in cutting characteristics, blocking characteristics, and re-ignition characteristics. Moreover, by repeating the molding process and the sintering process (including infiltration after sintering) twice or more, defects in the structure are further reduced, and stable interruption characteristics and re-ignition characteristics are exhibited.
[0147]
(Example 27)
In Examples 1 to 26 and Comparative Examples 1 to 17, the effect on cutting characteristics, re-ignition characteristics, and interruption characteristics was shown for the case of Cu-TiC alloy adopting TiC particles as an arc resistant component. The arc-proof component used in the present invention is not limited to TiC, and the effect is obtained.
[0148]
That is, even in the case of VC (vanadium carbide) as an arc resistant component, the same preferable characteristics were shown as compared with the standard example 1 (example 27).
[0149]
Thus, even if a part or all of TiC is replaced with VC, the same effect can be obtained.
[0150]
(Other examples)
In Examples 1 to 27 described above, Cu is used as the conductive component, but the same effect can be obtained by replacing part or all of Cu with Ag.
[0151]
Further, by forming a vacuum circuit breaker using a vacuum valve provided with contacts made of the contact materials of Examples 1 to 27 described above, a vacuum circuit breaker having both cutting characteristics and re-ignition characteristics is obtained. be able to.
[0152]
【The invention's effect】
As described above, according to the present invention, it is possible to achieve both cutting characteristics and re-ignition characteristics.
[Brief description of the drawings]
FIG. 1 is a table showing evaluation conditions for Examples 1 to 8 and Comparative Examples 1 to 8 of contact materials according to the present invention.
FIG. 2 is a table showing the evaluation conditions for Examples 9 to 17 and Comparative Examples 9 to 12 of the contact material according to the present invention.
FIG. 3 is a table showing the evaluation conditions of Examples 18 to 27 and Comparative Examples 13 to 17 of the contact material according to the present invention.
FIG. 4 is a table showing evaluation results of Examples 1 to 8 and Comparative Examples 1 to 8 of contact materials according to the present invention.
FIG. 5 is a table showing evaluation results of Examples 9 to 17 and Comparative Examples 9 to 12 of contact materials according to the present invention.
FIG. 6 is a table showing evaluation results of Examples 18 to 27 and Comparative Examples 13 to 17 of contact materials according to the present invention.
FIG. 7 is a table showing evaluation criteria for cutting current characteristics of examples and comparative examples of contact materials according to the present invention.
FIG. 8 is a table showing criteria for determining the re-ignition frequency of the contact material examples and comparative examples according to the present invention.
FIG. 9 is a table showing criteria for determining the breaking characteristics of examples of contact materials according to the present invention and comparative examples.

Claims (1)

In a contact material for a vacuum circuit breaker containing an arc resistant component composed of 30 to 80% by mass of TiC and a conductive component composed of Cu or / and Ag as the balance ,
The region of the conductive component is composed of a plurality of conductive component phases interspersed , and the conductive component phase is formed of conductive component particles or an aggregate thereof, and among the plurality of conductive component phases, 0.0001 to Rutotomoni conductive components phase with a cross-sectional area of 0.01 mm ² accounts for 5 to 65 area%, the thickness of conductive component phases having a cross sectional area of the 0.0001～0.01Mm ² is is 1~50μm A contact material for a vacuum circuit breaker .

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