JPS60248853A - 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 Sb 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% Sb 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. As the gap narrows, problems have arisen in welding resistance. 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 which has the stable contact resistance of an electrical contact material made of bismuth oxide and which has greatly improved welding resistance.

(Another means to solve the problem) One of the electrical contact materials of the present invention is Hismast 20% by weight.
and cadmium 0.1-5%, manganese 0.5-5%
% by weight, 0.5-5% by weight of antimony, the balance being silver, and one element is internally oxidized.

Another electrical contact material of the present invention includes 20% by weight of hismast, 0.1 to 5% by weight of cadmium, and 0.5% by weight of manganese.
It is a material consisting of 5 to 5% by weight of antimony, 0.5 to 5% by weight of antimony, 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 at 0.5 to 5 wt% antimony is that bismuth and cadmium improve welding resistance through low-temperature sublimation, and bismuth less than 1 wt% and cadmium 0.
．． Less than 1% by weight of bismuth has no effect, more than 20% by weight of bismuth lowers the melting point of the alloy so much that internal oxidation at high temperatures becomes difficult, and more than 5% by weight of cadmium deteriorates the welding resistance of silver-hismuth oxide. let Manganese is used to improve lubricant adhesion 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. Antimony is used to improve welding resistance, and if it is less than 0.5% by weight, it will not have that effect.
If it exceeds % by weight, the processability will deteriorate significantly. From the above, 20% by weight of bismust, 0.1-5% by weight of cadmium, 0.5-5% by weight of manganese, and 0.5-5% by weight of antimony.
Within this weight percent range, an electrical contact material with sufficiently satisfactory welding resistance can be obtained.

Furthermore, in another one of the electrical contact materials of the present invention, 20% by weight of bismast, 0.1-5% by weight of cadmium, 0.5-5% by weight of manganese, and 0.5-5% by weight of antimony.
The reason why iron group elements are added in an amount of 0.01 to 1% by weight is that when they are dispersed in electrical contact materials, the resulting uniform and fine dispersion of bismuth oxide and cadmium oxide makes the wear due to discharge uniform. This is because the contact resistance becomes more stable, and if it is less than 0.01% by weight, bismuth oxide and cadmium oxide 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) Materials having the composition of Example 1.2 shown in the left column of the table below were melted to form an atomized powder, and then internally oxidized at 600°C and 19 atm for 2 days. (・Maize powder is compressed and sintered, extruded and drawn, then cut and processed into a header.Head diameter: 5mm; Head height: 1.0mm; Crane: 1 leg diameter: 2.511m;
Fixed contact with leg length 2.5 mm, head diameter 4 tuna, 1i11 height 1.
1 tuna 5 leg diameter 2.8 tuna 5 leg length 1.6 prize group.

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

In addition, materials having the compositions of Examples 3 and 4 shown in the left column of the table below are melted and formed into chip shapes, which are internally oxidized at 600°C and 9 atm for 2 days, then compressed and sintered, and then extruded. , After drawing, cutting and header processing, head diameter 5i + m,
Head height 1.0 inu, leg diameter 2.5 inu.

Fixed contact with leg length 2.511111 and head diameter 4 pieces 1 head height 1
．． 1+m.

A movable contact with a leg diameter of 2.8 mm, a leg length of 1.6 mm, and a spherical head shape of 5R was obtained.

However, these electrical contacts were made using the electrical contact materials of Examples 1 to 4, and Soto-type electrical contacts and materials having the component compositions of the conventional examples shown in the left column of the table below were made in the same manner as in Example 1.2. When a glue head 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, the results shown in the right column of the table below were obtained.

Test conditions Voltage: AC100V 50I (z Current: 40A input, 10A steady load: Resistance Switching frequency: 20 times/min Number of switchings: Until welding occurs (blank below) As is clear from the table above, Example 1 Head-type electrical contacts made with the electrical contact materials of ~4 have a higher number of openings and closings before welding occurs than conventional electrical contact materials or hem-type electrical contacts, and have low welding resistance and low contact resistance. It can be seen that the values are equally 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] 1) 20% by weight of bismast, force 1~0.1~5
wt%, manganese 0, J~5 wt%, antimony 0.
An electrical contact material comprising 5 to 5% by weight and the balance silver, and which is internally oxidized. 2) Bismust 20% by weight, cadmium 0.1-5% by weight, manganese 0.5-5% by weight, antimony 0.5-5%
% by weight, 0.01 to 1% by weight of an iron group element, and the balance is silver, and is internally oxidized.