JPS59215436A - Electrical contact material - Google Patents

Abstract

PURPOSE:To obtain an electrical contact material having considerably improved welding resistance and stable contact resistance by internally oxidizing an alloy material having a specified composition consisting of Cd, Sn, Sb, Bi and the balance Ag. CONSTITUTION:This electrical contact material is obtd. by internally oxidizing an alloy material having a composition consisting of, by weight, 10-20% Cd, 0.5-5% Sn, 0.5-5% Sb, 0.1-3% Bi and the balance Ag. The composition may further contain 0.01-0.5% Fe group element.

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 H materials made of Ag-Cd0 are widely used because they have excellent adhesion resistance and stable contact resistance when the contact force and separation force of relays are large.

Recently, as relays have become smaller, contact force and separation force have decreased, contacts have become smaller, and contact gaps have become narrower, resulting in problems with welding resistance. For this reason, there is a demand for electrical contact materials with excellent welding resistance.

The present invention was developed as a result of 3υ efforts to meet such demands.
An electrical contact material has been discovered which has the same stable contact resistance as the electrical contact material made of g-Cd0, and whose welding resistance is significantly improved.

One of the electrical contact materials of the present invention contains Cd 10-20% by weight, Sn 0.5-5% by weight, and SbO 5-5% by weight.
.

It consists of BiO, 1 to 3 commercial weight balance Ag, and is internally oxidized.

Another part of the electrical contact material of the present invention, Cd 10-20
weight%, Sn 0.5-5 weight%, SbO, 5-5 weight%, BiO, 1-3 weight%, FC group element 0.01-0
．． It consists of 5% by weight, the balance being 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 for maintaining excellent welding resistance and stable contact resistance, and Cd is necessary for maintaining excellent welding resistance and stable contact resistance. If it is less than 1n% i'+Yi, good welding resistance will not be achieved, but if it exceeds 20% by weight, the abrasion resistance will deteriorate even if elements that improve the abrasion resistance are added, so 10 to 20% by weight. % stopping amount is preferred. Sn changes the shape of CdO from spherical to gold-like, and Sn oxide is thermally stable, so it is necessary for welding resistance. There is no effect, and if it exceeds 5% by weight, the Sn oxide will aggregate when the contact is opened/closed, and the contact resistance and temperature rise will decrease, which cannot be suppressed by the addition of +3j described later, so 0.5 to 5% by weight. % is suitable.

sb is necessary to improve welding resistance, and if it is less than 0.5% by weight, it has no effect, and if it exceeds 5% by weight, wear resistance deteriorates, so 0.5 to 5% by weight is preferable. be. Since the oxide of Bi is brittle and the solution is easy to solve, it is not connected to Fr't!
Power.

Necessary to improve welding resistance when the opening force is small, and to prevent Sn oxides from agglomerating during contact opening and closing, resulting in high contact resistance and temperature rise. 0.1% by weight. If it is less than 3% by weight, there is no effect, and if it exceeds 3% by weight, the melting point of the alloy will be extremely lowered, making internal oxidation at high temperatures impossible.
0.1 to 3% by weight is preferred. Fe group elements are added to improve arc resistance and tJ/l'i wear resistance, and if the amount is less than 0.01i, there is no effect;
If the vehicle volume % is exceeded, the contact resistance will be high and unstable, so 0
．． 01 to 0.5% by vehicle volume is suitable.

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゜2 obtained by internally oxidizing powder 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. A fixed contact with a diameter of 5 mm and a thickness of 1 mm made of electrical contact material of When we conducted this, we obtained the results shown in the right column of the table below.

Test condition voltage: AClooV 5011z
Current: input 40A, steady 10Af1. Load: Resistance Opening/closing frequency: 20 times/min Opening/closing frequency: Contact force until welding occurs: 40 g Breaking force: 45 g 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 13?1 more closing times before welding occurs than 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, the electrical contacts made of the electrical contact materials of Examples 1 to 7 were compared to the conventional example 1.
It can be seen that the performance is equivalent to or lower than that of the electrical contact made of No. 2 electrical contact material.

As can be seen from the above description, the electrical contact material of the present invention has a stable contact resistance equivalent to that of the conventional electrical contact material A4 made of A[-CdO, and has significantly improved welding resistance. Therefore, it can be said to be an epoch-making material that can replace the conventional electrical contact material made of Ag-Cd0.

Applicant: Tanaka Kikinzoku Kogyo Co., Ltd.

Claims (1)

[Claims] 1) c dto ~ 2oim%, Sn 0.5 ~ 5% by weight
, sbo, 5-5%, Bi 0.1-3% by weight, balance Ag, and is internally oxidized. 2) Cd 10-20mft%+SnO,
5-5 [%, 3bO, 5-5 wt%, Bi0.1-3
i amount % li'' An electrical contact material consisting of 0.01 to 0.5 amount % of group 6 elements and the balance being Ag, and which is internally oxidized.