JPS60245747A - Electrical contact material - Google Patents

Abstract

PURPOSE:To obtain an electrical contact material having stable contact resistance and superior welding resistance by compressing and sintering internally oxidized alloy powder having a specified composition consisting of Ag, Bi, Cd and Mn or further contg. an Fe group metal and by extruding and drawing the sintered body. CONSTITUTION:A molten alloy consisting of, by weight, 5-20% Bi, 0.1-5% Cd, 0.5-5% Mn and the balance Ag or futher contg. 0.01-1% Fe group metal such as Ni is atomized, and the resulting powder is internally oxidized. The powder is then compressed and sintered, and the sintered body is extruded, drawn, and cut to obtain an electrical contact material. This electrical contact material has stable contact resistance and superior welding resistance.

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. Silver-bismuth oxide has contact performance such as arc resistance, welding resistance, and stable contact resistance. With the narrowing of the contact gap, problems have arisen in 1Iit weldability.

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

The present invention was developed as a result of intensive research to meet such demands.
An electrical contact material has been discovered that retains 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 contains 5 to 20 weight percent bismuth, 0.1 to 5 weight percent cadmium, and 0.5 weight percent manganese.
~5% by weight, the balance being silver, and is internally oxidized.

Another electrical contact material of the present invention is bismuth 5-20
% by weight, cadmium 0.1-5% by weight, manganese 0.
It is a material consisting of 5 to 5% by weight, iron group elements o, oi to 1% by weight, and the balance silver, and is internally oxidized.

(Function) In the electrical contact material of the present invention, hismuth is 5-20% by weight, cadmium is 0.1-5% by weight, manganese is 0.5-5% by weight.
The reason for limiting the weight percentage is that good welding resistance cannot be obtained with less than 5% by weight of hiss, mass, 0.1% by weight of cadmium, and 0.5% by weight of manganese, and if it exceeds 20% by weight of bismuth, The melting point of the alloy is too low, making internal oxidation difficult at high temperatures. Both cadmium and manganese are useful for improving the welding resistance, but in the case of cadmium, if it exceeds 5% by weight, it will conversely deteriorate the welding resistance of silver-bismuth oxide. On the other hand, in the case of manganese, if it exceeds 5% by weight, layered precipitation will occur and the contact resistance will increase. From the above, within the ranges of 5 to 20% by weight of bismuth, 0.1 to 5% by weight of cadmium, and 0.5 to 5% by weight of manganese, an electrical contact material with sufficiently satisfactory welding resistance can be obtained. Furthermore, in another electrical contact material of the present invention, bismuth is 5 to 20% by weight and cadmium is 0.1 to 5% by weight.

Iron group elements 0.01-1 in addition to manganese 0.5-5% by market weight
The reason for adding % by weight is that when it is dispersed in an electrical contact material, the resulting uniform and fine dispersion of bismuth oxide and cadmium oxide equalizes consumption due to discharge, making the contact resistance more stable. Yes, 0
．． If it is less than 0.01% by weight, bismuth oxide and cadmium oxide will not be uniformly and finely dispersed, and if it exceeds 1% by weight, their segregation will increase and the contact resistance will become unstable.

Next, in order to clarify the effects of the electrical contact feed according to the present invention, specific examples and conventional examples will be described.

(Example) Materials not shown in the left column of the table below having the compositions of Examples 1 and 2 were melted to form atomized powder, and then internally oxidized at 600°C and 19 atm for 2 days to obtain the oxidized atomized powder. It is compressed and sintered, extruded and drawn, then cut and processed into a header, with a head diameter of 5 fins, a head height of 1.01, and a leg diameter of 2.5i+i.
Fixed contact with leg length 2.5+I+1 and l'1Jlf+l diameter 4 dragons 1 head height 1.1m++, leg diameter 2.8+im, 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 and formed into chip shapes, which were internally oxidized at 600°C and 9 atm for 2 days, and then compressed and sintered. After extrusion and drawing, cut and header processing, head diameter 5+u+,
Head height 1.0 dragon, leg diameter 2.5 dragon.

Fixed contact point of leg length 2.5 dragon, head diameter 4 mm, head height 1.1 fin.

Leg diameter 2.8mm, leg J = 1.6mm, head spherical 5R
A movable contact was obtained.

However, the rivet-type electrical contacts made with the electrical contact materials of Examples 1 to 4 and the same dimensions made with the materials of the conventional examples shown in the left column of the table below in the same manner as in Example 1.2. When the rivet-type electrical contact was assembled into a hinge-type relay and an opening/closing test was conducted under the following test conditions, the following results were obtained.
The results shown in 141 were obtained.

Test conditions Voltage: AC 100V 5011Z Current 2 Input 40'A, Steady 10A load: Resistance switching frequency = 20 times/min Number of switching: Until welding occurs (effects of the invention) As is clear from the table 1. Compared to conventional electrical contact materials or head-type electrical contacts, the Lichenoto type electrical contacts made with the electrical contact materials of Examples 1 to 4 have a greater number of openings and closings before welding occurs, and have excellent welding resistance. It can be seen that the contact resistance is equally low and stable with little fluctuation. 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-histmuth, and has significantly improved piece weldability, which is superior to that of the conventional electrical contact material made of silver-histmuth. It can be said to be an epoch-making product that can replace contact materials.

Applicant Tanaka Kikinzoku Kogyo Co., Ltd.

Claims (1)

[Claims] ■) 5 to 20% by weight of bismuth and 0.1 to 5% of cadmium
An electrical contact material which is internally oxidized and consists of M amount %, manganese 0.5 to 5% by weight, and the balance silver. 2) Bismuth 5-20% by amount and cadmium 0.1-
5% by weight, 0.5-5% by weight of manganese, and 0.5% by weight of iron group elements.
01 to 1% by weight, the balance being silver, and is internally oxidized.