JPS58126606A - Electric contact material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention is directed to an electrical contact material.

Conventionally, as electrical contact materials, silver-metal oxide type, silver-nickel type, silver-tungsten type, silver-graphite type, etc. have been used. 41, silver-nickel electrical contacts are widely used because of their good contact performance and workability. Conventionally, nickel with a weight ratio of 10- to 30- is often used. The reason for this is that the overall evaluation of contact resistance, welding resistance, and abrasion resistance required for electrical contacts is excellent. In the case of 10- or less, the contact performance is almost the same as that of silver, so it is not used in the past.
Recently, mechanical parts have become smaller, and as a result, the contact force, separation force, etc. are small, and the resistance is high or unstable, resulting in a final KFi conduction failure and the problem that the mechanical parts do not work properly. There is. The reason for this is that silver and nickel hardly dissolve in solid solution, so mixing silver powder and nickel powder,
compression.

Manufactured using a powder metallurgy method called extrusion. Therefore, silver powder and nickel powder are mechanically mixed and bonded together, and when this material is used as a t-w air contact, the nickel coagulates due to the gel heat during opening and closing and arc ripening. death,
This is also because nickel is oxidized to become nickel oxide. However, in the past, this problem could be solved by improving the mechanical parts, such as increasing the Fi contact force and separation force, but as mentioned at the beginning, it became impossible to deal with this problem as the mechanical parts became smaller.

The present invention has been made in view of the above circumstances with the object of stabilizing the contact resistance of silver-nickel electrical contact materials. It is an object of the present invention to provide an electrical contact material that has stable contact resistance without impairing the advantages of silver-nickel electrical contact materials: good workability, good welding resistance, and wear resistance. purpose.

In the present invention, aS is composed of a total of 5 to 10 nickel and at least one of tungsten carbide, titanium carbide, and lanthanum boride in a weight ratio of 0.05 to 0.4 s@l. It is an electrical contact material. All of these compounds are highly susceptible to arcing, and the addition of a small amount has the effect of dispersing the legs of the arc and preventing agglomeration of nickel oxide on the surface. Therefore, attempts have been made to uniformly disperse these compounds in the silver-nickel alloy material to prevent nickel agglomeration and improve contact performance.

Here, the weight of nickel is limited to 5 to 10%.
Below i51G, welding resistance and abrasion resistance deteriorate, and
This is because if the temperature becomes too high, nickel agglomeration and oxidation will become severe. Nine carbide tungsten titanium carbide, boride 2 tanta y #i α in the range of 05 to 0.4 works evenly on the silver-nickel alloy, and both compounds stabilize contact resistance without impairing welding resistance and abrasion resistance. let Previously, it was thought that if it was less than 0.4111, it would not be possible to prevent nickel agglomeration due to Joule heat and arc heat during electrical II point switching, but in this experiment, it was found that addition of less than 0.4-111 is also effective. It turned out to be a certain person. Therefore, the total amount of these additives was set to α05 to α4m.

Next, in order to clarify the effects of the electrical contact material according to the present invention, specific examples and conventional examples thereof will be described.

Example 1 Silver powder, nickel powder, and tungsten powder with a particle size of several tens of microns were mixed at a weight ratio of 90:'1.9:(11).This mixed powder was compressed and sintered several times. After that, hot extrusion and cold stretching were carried out.Then, the ζO wire was processed into a header to form a movable contact with a head diameter of 2.8m and a head diameter of 3.5m.
A fixed contact was obtained.

Example 2 Silver powder, nickel powder, tungsten powder and titanium carbide powder with a particle size of about 100 microns were mixed in a weight ratio of 94:&8:0.1:
It was mixed in the proportion of alpha grass. A movable contact and a fixed contact were obtained using this mixed powder in the same manner as in Example 1.

Example 3 Silver powder, nickel powder, and lanthanum boride powder each having a particle size of about 100 microns were mixed in a weight ratio of 90:9.9:α1.

A movable contact and a fixed contact were obtained using this mixed powder in the same manner as in Example 1.

Conventional example 1 Silver powder and nickel powder with a particle size of several tens of microns are mixed in a weight ratio of 90
: Mix at a ratio of 1G. This mixed powder was repeatedly compressed and sintered, then hot extruded and cold wire drawn. Then, this wire was subjected to header processing to obtain a movable contact with a head diameter of 28 cm and a fixed contact with a head diameter of 3.5 mm.

Conventional @2 Silver powder and nickel powder with a particle size of about 100 microns are mixed at 70=30
Mix in the proportion of A movable contact and a fixed contact were obtained using this mixed powder in the same manner as in Conventional Example 1.

Therefore, 69 pairs of rivet-type electrical contacts of Examples 1 to 3 and Conventional Examples 1 and 2 were subjected to opening/closing tests under the following test conditions, and the welding resistance and contact resistance were investigated, and the results are shown in the table below. Get it.

Test conditions Voltage AClooV 50Hz current Input current 20A Steady current 5A Switching frequency 20 times/min Load Resistance switching frequency Until welding occurs As is clear from the results in the above table, electrical contacts made with the electrical contact material of the present invention It can be seen that the contact resistance is more stable than that of conventional electrical contacts, and the welding resistance is as excellent as that of conventional electrical contacts.

Applicant: Tanaka Kikinzoku Kogyo Co., Ltd. Kinsha 19-

Claims (1)

[Claims] Nickel 5-1o- and tungsten carbide in weight ratio,
An electrical contact material comprising a total of 0.05 to 0.4 qII of at least one of titanium carbide and lanthanum boride, and the balance being silver.