JPS58193332A - Electric contact material - Google Patents

Abstract

PURPOSE:To enhance the welding resistance, the fire resistance, the consumption resistance and the strength of an electric contact material and to make it lightweight, by forming the electric contact material from a specific composition containing SiC, a carbon fiber and Ag to reduce the contact resistance of the obtained electric contact material. CONSTITUTION:This electric contact material has a composition substantially consisting of 2-20wt% SiC, 0-5wt% carbon fiber and the remainder Ag. That is, SiC and the carbon fiber are dispersed throughout Ag.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical contact material made of Ag + SiO + carbon fiber suitable for use in air switches such as circuit breakers.

BACKGROUND ART Conventionally, materials of the Mug0OdO or 6τMog+WO series have been mainly used as electrical contacts for air switches such as circuit breakers. However, there is a desire to reduce the amount of precious metal Ag, which is the main component of these contact materials.
Furthermore, as the breaking capacity of circuit breakers increases and product dimensions become smaller, it is becoming increasingly difficult to fully satisfy the characteristics required for products using conventional contact materials. In other words, when a Mug4-Wo type material is used, a highly insulating vzD@ compound is generated on the contact surface due to one arc, which causes a problem of temperature rise due to an increase in contact resistance, and when an AgOdO type material is used, the contact Although the resistance is relatively stable, it has the disadvantage of low breaking capacity due to low heat resistance or welding resistance.

The contact material of the present invention overcomes the above-mentioned problems and drawbacks, and contains substantially 2 to 20% SiO in Ag.
% by weight (the same applies hereinafter) and carbon fibers (0 to 5% by weight) are dispersed therein.

SiO used in the contact material of the present invention is hard (hardness 32
00197mm2, Hma2500), which increases the strength and hardness of the contact material and improves wear resistance.It also has a high melting point (2700°C), which improves the fire resistance of the contact material. This improves the welding resistance of contact materials. Furthermore, SiO has a low specific resistance, is chemically stable even at high temperatures, and has a relatively stable contact resistance.

The carbon fiber used in the contact material of the present invention has low wettability with molten metal, so it improves the welding resistance of the electrodeposition material, and has a low specific resistance, preventing oxidation of the contact material even at high temperatures, and making contact with It has the effect of keeping resistance low. Furthermore, carbon fiber is a high-strength material (tensile strength of 600 to 550 kg/mm).
), and by dispersing it in Ag, a carbon fiber reinforced metal is constructed, which increases the strength of the contact material.It also has a high melting point (3700°0), making the contact material excellent in fire resistance. do.

Furthermore, the specific gravity of 810 and carbon fiber is 6.17.
Since it is as small as 1.75, it has the effect of reducing the weight of the contact material.

As described above, the present invention provides a lightweight, high-strength contact material with low contact resistance, excellent adhesion resistance, fire resistance, and abrasion resistance by dispersing SiO and carbon fibers in Ag. It is something to do.

The contact material of the present invention consists essentially of 3102-20% carbon fiber, 0-5% carbon fiber and the balance Ag. If the SiO content is less than 2%, the resulting contact material will be consumed in a large amount and the effect of the addition will not be sufficiently exhibited, and if the SiO content exceeds 20%, the contact resistance will increase, which is undesirable.

On the other hand, if the carbon fiber content exceeds 5 carbon fibers, the amount of consumption of the material becomes large, which is not preferable.

In addition to the above-mentioned components, other substances may be added to the contact material of the present invention depending on the required characteristics.

Next, the electrical contact material of the present invention will be explained with reference to Examples.

Example 6 A mixed powder containing 25 mesh Ag powder, SiO powder with a diameter of 1 to 10 μm, and carbon fiber with a diameter of about 7 μm and an average fiber length of 600 μm was put into a cylindrical mold with a diameter of jQ mm and the pressure was 5 t/am. Pressure-formed to a plate thickness of 2m.
m, a disk-shaped compressed body was prepared, and this was placed in a nitrogen gas flow for 8
It was heated and sintered at a temperature of 50°0.

Next, the obtained sintered body is made into a shape with predetermined contact dimensions (4 mm x 4 mm).
nm x 1.2 m 1 m ), which was incorporated into a circuit breaker and subjected to overload tests and durability tests.

In addition, a specimen for comparison was prepared in the same manner as above.
i was manufactured and tested. The compositions are shown in Table 1 together with those of Examples.

Table 1 (Note) Gr is graphite.

In Table 1, the specific gravity is SiOL 17 and carbon fiber 1.75.
, WO15-8q Gr2-2, the actual amount of Ag used is smaller in the example (road silver composition).゛The test conditions were as follows, and the test consisted of an overload test followed by a durability test.

(1) Overload test 11 Pressure Ao 2247 N Sliding current 505m Number of opening/closing 50 times (2) Endurance test voltage Muc 2247 s Sumizuri electric
Current 51m Opening/closing times 6000 times energized 10 times 4000 times non-energized The results are shown in Figure 1 for temperature changes, and in Figure 2 for consumption. From FIG. 1 and FIG. 2, the electrical contact material body of the present invention)
Compared to Comparative Sample 1 (CB), it was observed that the temperature rise and amount of wear after the durability test were significantly improved.

In addition, in the above test, some welding was observed in the comparative sample, but no welding occurred in the electrical contact material of the present invention.

Incidentally, Fig. 1 S shows a scanning electron micrograph (×500 times) showing the cross-sectional structure of the electrical contact material sample of the present invention obtained in Example. In the figure, 1 is 5iOs2 is carbon fiber. Moreover, FIGS. 4 and 5 are photographs showing the measurement results of elemental analysis performed using an X-ray microanalyzer analyzer. FIG. 4 shows Okα based on wavelength dispersion, and FIG. 5 shows MugKα and 8iKα based on energy dispersion.

[Brief explanation of the drawing]

1st rlJ is a graph showing the temperature rise after the test, 2nd cabinet is a graph showing the amount of consumption after the test, Fig. 6 is a scanning electron micrograph (500x), and Figs. 4 and 5 are X-ray micrographs. It is a photograph showing the results of elemental analysis by an analyzer analyzer. Agent Makoto Kuzuno (and 1 other person) B: A'2 Figure 8 B Figure 3 Figure 4 = 155 Figure 5 Procedure amendment (method) 57924 % formula % 2, Name of invention Electrical contact material 3, Amendment Representative Hitoshi Katayama August 51, 1982 (shipment date) 6. Subject of amendment (1) ``Detailed explanation of the invention'' column in the specification (2) ``Brief description of the drawings'' in the specification (8) Drawing 7, Contents of amendment (1) On page 6, line 12 of the specification, ``shows'' is corrected to ``shows a sketch of.'' (2) From the last line of page 6 to line 1 of page 7, “Scanning lid...”
...(500x)" to "Scanning plate electron microscope photograph showing the cross-sectional structure of the electrical contact material of the present invention obtained in the example (
500x) sketch diagram.” (8) Correct the drawing (Figure 6) as shown in the attached correction diagram i1 (Figure 6). (4) Add reference photos. 8. Highlights of attached documents (1) Amended drawings (Illustration 6) 1 copy 1
1 (2) Reference photo 1 written amendment (voluntary) Case description Name of patent application 1982-77108 Person making amendments to electrical contact materials Representative: Hitoshi Katayama, Attorney 5, Subject of amendment (1) Column 6 of "Detailed Description of the Invention" of the specification, contents of amendment (1) "Electrodeposition" in the third line from the bottom of page 2 of the specification is corrected to "contact". (2) Amend the information in Table 1 on page 5. that's all

Claims (1)

[Claims] (1) Substantially Si02-20% by weight1 carbon fiber 0-5
An electrical contact material consisting of a heavy weight compound and a mug residue.