JPS62297428A - Electric contact material - Google Patents

Abstract

PURPOSE:To obtain an electric contact material replacing conventional Ag-Sn oxide electric contact point materials and excellent in consumption resistance and deposition resistance, by adding a specific percentage or less, in total, of respectively prescribed percentages of Sn, Ni, and (In+Bi) to Ag and by subjecting the above to internal oxidation. CONSTITUTION:The electric contact material of this invention is obtained by adding <=30wt%, in total, of 6-15wt% Sn, 1-20wt% Ni, and 0.01-10wt% (In+Bi) to Ag and by applying internal oxidation to the above. That is, in said electric contact material, deposition resistance is improved by adding Ti to an Ag-Sn alloy so as to increase the additive amount of Sn to be internally oxidized and increase the amount of Sn oxide, and further, consumption resistance is improved by adding In and Bi to the Ag-Sn alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to electrical contact materials, and particularly to improvements in electrical contact materials in which an Ag-Sn alloy is internally oxidized.

(Prior art and its problems) Electrical contact materials made of internally oxidized Ag Sn alloys are said to have excellent welding resistance, but this is still not sufficient.

For this reason, it may be possible to further improve the welding resistance by increasing the content of Sn oxide through internal oxidation, but Sn5.
If the content exceeds 5 wt%, internal oxidation becomes difficult. Therefore, it has been impossible to further improve the welding resistance. Furthermore, the abrasion resistance was not fully satisfactory. That is, the internal oxidation structure of the AgSn alloy is non-uniform, with Sn oxide precipitated at grain boundaries or in layers, resulting in poor wear resistance.

Therefore, as a result of intensive research to improve electrical contact materials made by internally oxidizing conventional Ag-Sn alloys, the present inventors discovered that Ag-Sn
Sn is internally oxidized by adding Ni to the n alloy.
We have discovered an electrical contact material in which welding resistance is improved by increasing the amount of Sn oxide added and Sn oxide is added, and wear resistance is improved by adding In and Bi.

(Means for solving the problem) The electrical contact material of the present invention contains 5 to 15-t% of Sn in Ag.
Nil ~20wt%, In and Bi 0.01~10
Within the wt% range, a total of 30-t% or less is added and internally oxidized.

In the electrical contact material of the present invention, the amount of Sn added is 6 to 1.
The reason for setting it to 5 wt% is that if it is less than 5n6i+t%, excellent welding resistance cannot be obtained, and if it exceeds 15 wt%, internal oxidation becomes difficult even with the addition of Ni. The reason why the amount of Ni added was set to 1 to 20 wt% is because it is difficult to internally oxidize Sn well when Ni is less than 1 wt%.
This is because if it exceeds 0 wt%, it is too much to promote Sn internal oxidation and the workability of the alloy deteriorates. Furthermore, the reason for adding In and Bi is to make the Sn oxide uniform after internal oxidation and improve the welding resistance.If the total amount is less than 0.01wt%, the welding resistance cannot be improved. , when it exceeds 10-t%, internal oxidation becomes difficult;
Further, the precipitation of oxides in Ag after oxidation is too large, which impairs wear resistance.

However, the reason why the total amount of each of the above-mentioned additives is set to be 30 wt % or less is because if it exceeds 30 wt %, the Ag-oxide alloy after internal oxidation becomes brittle and the wear resistance is impaired.

Next, in order to clarify the effects of the electrical contact material according to the present invention, the amount of wear and the number of weldings performed by inching tests of electrical contacts made according to specific examples and conventional examples will be described.

(Example) In the embodiments of the present invention shown in numbers 1 to 16 of the component composition shown in the left column of the table below, and the conventional examples shown in Arashi 17 and 18, plate materials were manufactured by melt casting (or powder metallurgy method), and waxed. To make it easier to attach, silver was crimped on one side, rolled into a 1 mm thick plate, punched into a 7.5φ crane using a press, and rolled at 700°.
These electrical contact materials are obtained by internal oxidation for 120 hours in an oxygen atmosphere of C6 atmospheres, and these electrical contact materials are brazed to copper alloy base materials to make electrical contacts for relays. An inching test was conducted under the following test conditions to measure wear resistance and welding resistance, and the results shown in the right column of the table below were obtained.

Inching test conditions Contact dimensions 7.5φ Dragon X1. QLmm voltage
230V - Current 175A Power factor 0.84 Energizing time 15Hz Opening/closing frequency 20 times/min Test number 50,000 times As is clear from the values shown in the right column of the above table, each relay made from the electrical contact material of the present invention It can be seen that the electrical contacts have excellent wear resistance as the amount of wear is reduced compared to conventional electrical contacts, and the number of welding occurrences is low, indicating that they have excellent welding resistance.

(Effects of the Invention) As detailed above, the electrical contact material of the present invention has wear resistance,
Since it has excellent adhesion resistance, it can be said to be an epoch-making product that can replace the conventional Ag-Sn oxide electrical contact material.

Claims (1)

[Claims] Ag, Sn6~15wt%, Ni1~20wt%, I
n and Bi within the range of 0.01 to 10 wt%, with a total of 30
Internally oxidized electrical contact material with wt% or less added.