JPS60248852A - Electrical contact material - Google Patents

Abstract

PURPOSE:To obtain an electrical contact material having stable contact resistance and considerably improved welding resistance by adding specified percentages of Bi, Cd, Mn and Te to Ag and carrying out internal oxidation. CONSTITUTION:A material consisting of, by weight, 1-20% Bi, 0.1-5% Cd, 0.5-5% Mn, 0.5-5% Te and the balance Ag or further contg. 0.01-1% Fe group element is internally oxidized to obtain the electrical contact material. Stable electrical contacts which hardly vary are obtd. by using the electrical contact material.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to electrical contact materials.

(Prior Art and its Problems) Silver-bismuth oxide has conventionally been used as one of the electrical contact materials manufactured by internal oxidation method. Silver-bismuth oxide has contact performance such as excellent arc resistance and welding resistance, and stable contact resistance. gear,
Problems have arisen in welding resistance due to the narrowing of the gap. For this reason, there is a demand for electrical contact materials with even better welding resistance.

(Object of the Invention) The present invention has been made to meet such a demand, and is
It is an object of the present invention to provide an electrical contact material that has the stable contact resistance of an electrical contact material made of bismuth oxide and has greatly improved welding resistance.

(Means for Solving the Problems) One of the electrical contact materials of the present invention is bismast 20% by weight.
, cadmium 0.1~5% by weight, manganese 0.5~
5% by weight of tellurium, 0.5-5% by weight of tellurium, and the balance of silver, and is internally oxidized.

Another electrical contact material of the present invention is 1. bismust 20
% by weight, cadmium 0.1-5% by weight, manganese 0.
The material is composed of 5 to 5% by weight of tellurium, 0.5 to 5% by weight of tellurium, and the balance silver, and is internally oxidized.

In the electrical contact material of the present invention, 20% by weight of bismast
and cadmium 0.1-5% by weight, manganese 0.5-5%
The reason why bismuth and cadmium are set to 0.5 to 5% by weight is that bismuth and cadmium improve welding resistance due to their low-temperature sublimation properties.
If it is less than 5% by weight, it has no effect; if it exceeds 20% by weight, the melting point of the alloy will drop too much and internal oxidation at high temperatures becomes difficult; if it exceeds 5% by weight, cadmium will deteriorate the welding resistance of silver-bismuth oxide. . Manganese is used to improve welding resistance; if it is less than 0.5% by weight, it has no effect, and if it exceeds 5% by weight, layered precipitation occurs, increasing contact resistance and temperature rise. Tellurium is bismuth.

Like cadmium, it improves welding resistance through low-temperature sublimation, and if it is less than 0.5% by weight, it has no effect.
If it exceeds 5% by weight, processability becomes extremely poor. From the above, bismust is 20% by weight.

Within the ranges of 0.1 to 5% by weight of cadmium, 0.5 to 5% by weight of manganese, and 0.5 to 5% by weight of tellurium, an electrical contact material with sufficiently satisfactory welding resistance can be obtained.

Furthermore, in another electrical contact material of the present invention, in addition to 20% by weight of hismast, 0.1 to 5% by weight of cadmium, 0.5 to 5% by weight of manganese, and 0.5 to 5% by weight of tellurium, The reason for adding group elements in an amount of 0.01 to 1% by market weight is that when dispersed in electrical contact materials, the resulting uniform and fine dispersion of bismuth oxide and oxidizing power of 1.0mium reduces consumption due to discharge. This is because contact resistance becomes more stable due to uniformity; if it is less than 0.01% by weight, bismuth oxide and oxidizing power of 1-Sum will not be uniformly and finely dispersed;
If it exceeds % by weight, segregation of itself increases and contact resistance becomes unstable.

(Example and Conventional Example) After melting the material having the composition of Example 1.2 shown in the left column of the table below and making it into atomized powder, it was heated at 600°C, 9 atm,
After 2 days of internal oxidation, the oxidized atomized powder was compressed and sintered, extruded and drawn, then cut and processed into hesogroometry. 5+u,
Leg length 2.5 IN 11 ψ fixed contact and head il 4 fl,
Head height 1.1m, leg diameter 2.3mm, leg length 1.6mm.

A movable contact with a spherical head height of 5R was obtained.

In addition, materials not shown in the left column of the table below having the compositions of Examples 3 and 4 were melted, formed into chip shapes, internally oxidized at 600°C and 9 atm for 2 days, and then compressed and sintered. After extrusion and drawing, cut and sodder to a head diameter of 5 mm.
, head height 1.0 crane 9 leg diameter 2.5 parts.

A fixed contact of a crane with a leg length of 2.5 mm and a tuna with a head diameter of 4 fins and a head height of 1.1 mm.

A movable contact with a leg diameter of 2.3++ m, a leg length of 1.6 mm, and a spherical head shape of 5R was obtained.

However, using the electrical contact materials of Examples 1 to 4, or using the same method as in Example 1.2, a navel I-type electrical contact and a material having the component composition of the conventional example shown in the left column of the table below were made. A rivet-type electrical contact of the same size was assembled into a hinge-type relay and an opening/closing test was conducted under the following test conditions, and the results shown in the right column of the table below were obtained.

Test conditions Voltage: AC100V 50Hz Current 2 Input 40A, Steady 10A Load: Resistance Switching frequency: 20 times/min Switching/closing frequency: Welding salt (hereinafter referred to as the margin) As is clear from the table above, Examples 1 to 4 L-type electrical contacts made with electrical contact materials have a higher number of openings and closings before welding occurs than conventional electrical contact materials, and have excellent welding resistance and the same contact resistance. It can be seen that the value is low and stable with little variation.

(Effects of the Invention) As detailed above, the electrical contact material of the present invention has a stable contact resistance equivalent to that of the conventional electrical contact material made of silver-bismuth, and has significantly improved welding resistance. Therefore, it can be said to be an epoch-making product that can replace conventional electrical contact materials.

Applicant Tanaka Kikinzoku Kogyo Co., Ltd.

Claims (1)

[Claims] ■) A material consisting of 20% by weight of bismust, 0.1 to 5% by weight of cadmium, 0.5 to 5% by weight of manganese, 0.5 to 5% by weight of tellurium, and the balance being silver, and electrical contact materials that are internally oxidized. 2) 20% by weight of bismust, 0.1 to 5% by weight of cadmium, 0.5 to 5% by weight of manganese, 0.5 to 5% by weight of tellurium, 0.01 to 1% by weight of iron group elements, and the balance silver. An electrical contact material which is internally oxidized.