JPS59219442A - Electrical contact material - Google Patents

Abstract

PURPOSE:To obtain an electrical contact material having a stable contact resistance value as well as superior resistance to welding, arc and consumption by adding specified amounts of In, Zn and Bi to an Ag-CdO type electrical contact material, further adding an Fe group metal as required, and carrying out internal oxidation. CONSTITUTION:Fine grains having a composition consisting of, by weight, 10- 20% Cd, 0.5-5% In, 0.5-5% Zn, 0.1-3% Bi and the balance Ag or further contg. 0.01-0.5% Fe group metal such as Fe, Ni or Co are internally oxidized, compressed, and sintered. The sintered body is extruded and drawn to manufacture an electrical contact material. This contact material has a stable and low contact resistance value as well as superior resistance to welding, arc and consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electrical contact materials, and particularly to improvements in electrical contact materials made of Ag-Cd0.

Electrical contact materials made of Ag-Cd0 are subject to large amounts of wear due to arcing, and are inferior in arc resistance and wear resistance, resulting in deterioration of withstand voltage characteristics and insulation resistance; however, they have excellent welding resistance and stable contact resistance. Therefore, it is widely used.

In recent years, with the miniaturization of relays, there has been a trend toward a reduction in contact force and separation force, miniaturization of contacts, and narrowing of contact gaps.

For this reason, there is a demand for electrical contact materials that have excellent welding resistance, stable contact resistance, and excellent arc resistance and wear resistance.

The present invention was developed as a result of intensive research to meet such demands.
An electrical contact material has been discovered which retains the excellent welding resistance and stable contact resistance of the -Cd0 electrical contact material, and which has significantly improved arc resistance and wear resistance.

One of the electrical contact materials of the present invention contains 10 to 20% by weight of Cd, 0.5 to 5% by weight of In, and 0.5 to 5% of Zn.
5% by weight.

It consists of 1 to 3% by weight of Bio, the balance being Ag, and is internally oxidized.

Another electrical contact material of the present invention is Cd 10-20
Weight%, I n 0.5~5 Background weight Zn0.5~
5% by weight, B i O, 1 to 3% by weight, Fe group element 0.01 to 0.5% by weight, and the balance is Ag, and is internally oxidized.

The reason why the component composition of the electrical contact materials of the present invention is limited as described above is as follows.As is well known, Cd is necessary to maintain excellent welding resistance and stable contact resistance. If it is less than 20% by weight, good welding resistance cannot be obtained, and if it exceeds 20% by weight, the abrasion resistance deteriorates even if elements that improve the abrasion resistance are added.
0% by weight is preferred. In is necessary to improve arc resistance and wear resistance, and if it is less than 0.5% by weight, it has no effect.
If it exceeds 5% by weight, In oxides will aggregate when the contacts are opened and closed, increasing the contact resistance and temperature rise, which cannot be suppressed by adding Bi, which will be described later. Therefore, 0.5 to 5% by weight is preferable. Zn is necessary to improve wear resistance and arc resistance.
If it is less than 0.5% by weight, there is no effect, and if it exceeds 5% by weight, Zn oxides will precipitate in a layered manner and the contact resistance will increase, so 0.5 to 5% by weight is suitable. Bi is necessary to prevent In oxides from agglomerating during contact opening and closing, resulting in high contact resistance and temperature rise. If it is less than 0.11% by weight, it has no effect, and if it exceeds 3% by weight, it will lower the melting point of the alloy. 0.0.
1 to 3% by weight is preferred. Fe group elements have arc resistance,
This is added to improve wear resistance by -N.
．． If it is less than 0.01% by weight, there is no effect, and if it exceeds 0.5% by weight, the contact resistance will be high and it will become unstable.
0.5% by weight is preferred.

Next, electrical contacts made using the electrical contact material according to the present invention and the conventional electrical contact material will be explained.

Electrical contact materials of Examples 1 to 7 and Conventional Example 1 obtained by internally oxidizing powders and granules having the composition shown in the left column of the table below, and then undergoing processes such as compression, sintering, extrusion, and drawing. Baking soda with a diameter of 5 made of electrical contact material of ゜2, a fixed contact with a thickness of 1vA and a diameter of 4
mm, thickness 1. A contact opening/closing test was conducted under the following test conditions with the movable contacts of bt and 5R facing each other, and the results shown in the right column of the table below were obtained.

Test conditions Voltage: AClooV 50Hz Current: 40A input, 10A steady load:
Resistance opening/closing frequency: 20 times/min Number of opening/closing: Until welding occurs Contact force: 40 g Peeling force: 45 g (Left in the margin below) As is clear from the values shown in the right column of the table above, Examples 1 to 2
The electrical contact made of the electrical contact material No. 7 has a similar number of openings and closings until welding occurs, and has the same excellent welding resistance as the electrical contact made of the electrical contact material No. 1.2 of Conventional Example 1. It can be seen that it is equally low and stable with little variation. Regarding the amount of arc consumption, Examples 1 to 7
It can be seen that the electrical contacts made of the electrical contact materials shown in FIG.

As can be seen from the above description, the electrical contact material of the present invention has excellent welding resistance and stable contact resistance equivalent to the conventional electrical contact material made of Ag-Cd0, and also has arc resistance and
The wear resistance has been significantly improved, so it is better than the conventional A.
It can be said that it is an epoch-making product that can replace the electrical contact material made of g-Cd0.

Applicant: Tanaka Kikinzoku Kogyo Co., Ltd.

Claims (1)

[Claims] 1) 0610-20% by weight, In 0.5-5% by weight,
Zn 0.5-5% by weight, BiO, 1-3% by weight, balance A
An electrical contact material consisting of g and internally oxidized. 2) Cd 10-20% by weight, In 0.5-5
Weight%, Zn0.5-5% by weight, B i 0.
An electrical contact material consisting of 1 to 3% by weight, 0.01 to 0.5% by weight of Fe group elements, and the balance being Ag, and which is internally oxidized.