JPS5920436A - Electrical contact material - Google Patents

Abstract

PURPOSE:To obtain an electrical contact material saving silver consisting of prescribed percentages of TiC and carbon fibers and the balance essentially Ag, capable of reducing the size of an air break switch of a circuit breaker or the like, and having improved performance. CONSTITUTION:This electrical contact material consists of 2-40wt% TiC, 0- 10% carbon fibers and the balance essentially Ag. The contained TiC has 4.9 specific gravity, the carbon fibers have 1.75 specific gravity, and the values are lower than 15.8 specific gravity of conventional WC, so the weight of the electrical contact material can be reduced as compared to a conventional one. Since the TiC and carbon fibers are contained in Ag in a dispersed state, this electrical contact material has low contact resistance, superior resistance to welding, fire and consumption, and high strength, and it is light in weight.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electrical contact materials. For more details, see Silver (
The present invention relates to an electrical contact material made of titanium carbide (Ag), titanium carbide (Tie), and carbon fiber, and which can be suitably used for air switches such as circuit breakers.

Traditionally, Ag-WO or Ag-0dO materials have been mainly used as electrical contact materials for air switches such as circuit breakers. Highly insulating tungsten
There is a problem that oxides of Ag-01 are formed on the contact surface, and the temperature of the contact increases due to an increase in contact resistance.
When using 0 series materials, the contact resistance is relatively stable, but there is a drawback that the breaking capacity is reduced due to poor fire resistance or welding resistance.

Recently, there has been a desire to reduce the amount of precious metal Ag used, which is the main component of electrical contact materials, and with the trend toward smaller circuit breakers and increased breaking capacity, there are increasing demands on circuit breakers. There is an increasing need for electrical contact materials that can fully satisfy the characteristics.

Therefore, the inventors of the present invention conducted extensive research to eliminate these drawbacks, and found that by dispersing TiO and carbon fibers in Ag, the amount of Ag used can be reduced, and air switches such as circuit breakers can be We have completed an electrical contact material that can be miniaturized and improve its performance.

That is, the electrical contact material of the present invention has a T102 to 40% (
It is an electrical contact material consisting essentially of 0 to 10% of carbon fiber and the balance of Ag (wt%).

TiO used in the electrical contact material of the present invention is hard (hardness 3200 kp/mm"), which increases the strength and hardness of the electrical contact and improves wear resistance. Also, the melting point of TiO (3400°C) Because of the high Ti
Since O has a small resistivity and is chemically stable even at high temperatures, the contact resistance of electrical contacts is also relatively stable.

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 contact and
It has a low specific resistance and is effective in preventing oxidation of the contact material even at high temperatures and reducing contact resistance. In particular, it also has the effect of preventing the oxidation of TiO. Furthermore, carbon fiber is a high-strength material (tensile strength of 300 to 350kp/m
m2), and by dispersing it in Ag, carbon fiber-reinforced metal is constructed, which increases the strength of the contact, and its high melting point (3700°0) improves the fire resistance of the contact.

Further, while the specific gravity of Wa used as a conventional electrical contact material is 15.8, the specific gravity of TiO and carbon fiber contained in the electrical contact material of the present invention is 4.8.
9 and 1.75, the weight of the contact material can be reduced compared to conventional ones.

As described above, the electrical contact material of the present invention has T in Ag.
By dispersing iO and carbon fibers, it is a lightweight, high-strength electrical contact material with low contact resistance, excellent welding resistance, fire resistance, and abrasion resistance.

The electrical contact material of the present invention has the above-mentioned <TiO2-4
0%, carbon fiber 0-10% and the balance being substantially more than Ag. If the TiO content is less than 2%, the resulting electrical contact material will be consumed in a large amount, and the effect of the addition will not be sufficient. Moreover, if the TiO content exceeds 40%, the contact resistance of the resulting electrical contact material will increase, which is not preferable. On the other hand, if the carbon fiber content exceeds 10%, the amount of consumption of the resulting electrical contact material increases, which is not preferable.

In addition to the above-mentioned TiO and carbon fibers, other substances may be added to the electrical contact material of the present invention depending on its use and required characteristics.

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

Example 3 25 mesh Ag powder and T10 with a particle size of 1 to 5 μm
The combined powder mixture was put into a cylindrical mold with a diameter of 10 mm, and pressure molded at a pressure of 3 T/am" to produce a disk-shaped compressed body with a plate thickness of 2 mm. The resulting compressed body was placed in a nitrogen gas flow. 8
It was heated and sintered at a temperature of 50°0. Furthermore, the sintered body was heated to 4 T.
Repressurization was performed at a pressure of on/am2. Figures 1 (magnification: 40x) and 2.
It is shown in the figure (400x magnification). The composition of this example is Ag
90%, rta, 5.5%, carbon fiber 3.5%. In addition, in FIG. 2, (1) is TiO.

(2) is carbon fiber, and (8) is matrtx Ag. As can be seen from the cross-sectional structure observation photographs shown in Figs. 1 and 2, the electrical contact material of the present invention has TiO and carbon fibers uniformly dispersed in Ag, and has excellent wear resistance and welding resistance. The effects of the present invention, such as excellent heat resistance and fire resistance, can be improved.

The electrical contact material of the present invention has low contact resistance and can constitute an electrical contact with excellent wear resistance, welding resistance, and fire resistance, and when used in air switches such as circuit breakers, Ag It has the excellent effect of reducing the amount used, as well as reducing the size of air switches such as circuit breakers and improving their performance, and has extremely great practical value.

[Brief explanation of the drawing]

FIGS. 1 and 2 are 40x and 400x magnification photographs, respectively, of cross-sectional structures of the electrical contact materials of the present invention obtained in Examples, taken with a scanning electron microscope. (Drawing code) (1): Tla (2): Carbon fiber (8): Matrix Ag Agent Shin Kuzuno (1 person) Procedural amendment (method) 57 II 20 Showa U Year Month Day 1 , Incident Display Patent Application No. 129462/1982 2
, Title of the invention Electrical contact material 3, Person making the amendment Representative: Hitoshi Katayama Department 4, Agent 5, Date of amendment order: October 26, 1980 (shipment date) 6. Subject of amendment (1) Specification (2) "Brief explanation of drawings" column (8) Drawing 7, contents of amendment (1) "Photo" on page 5, line 12 of the specification has been changed to "-" Correct it with "Sketches of photos". (2) Correct ``Photo'' on page 5, line 17 to ``Photo sketch.'' (3) Correct ``Photo'' on page 6, line 16 to ``Photo sketch.'' (4) The drawings (Figs. 1 and 2) are attached to the attached corrected drawings (Fig. 1).
Correct as shown in Figures and Figure 2). (5) Add reference photos. 8. List of attached documents

Claims (1)

[Claims] (1) An electrical contact material consisting essentially of 2 to 40% by weight of titanium carbide, 0 to 10% by weight of carbon fibers, and the balance being silver.