JPS5810449B2 - electrical contact materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical contact material that has better adhesion resistance, contact resistance characteristics, and discharge wear resistance than conventional contact materials, and also has better welding resistance.

The present inventors have filed Japanese Patent Application No. 53-72171 (Japanese Unexamined Patent Publication No. 54-1
63357), Si was added to Ag.

We propose an electrical contact material in which a silver thread eutectic alloy containing 1 to 10 at% of one or more of Ge, Bi, and Fe is internally oxidized, and when the amount of Si and Ge is less than 1 at%, the internal oxidation effect does not occur. We made it clear that the patent application No. 54-3552
6 (Japanese Unexamined Patent Publication No. 55-128555) proposed an electrical contact material in which a silver-based alloy containing up to 17 at% of one or more of Si and Ge in Ag was internally oxidized. It has become clear that machining is possible.

Furthermore, Japanese Patent Application No. 54-35527 (Japanese Unexamined Patent Publication No. 55-12855)
6), one or more of Si and Ge is added to 8g.
~17at%) Au, Pt, Pd+Rh, RutOs,
We propose an electrical contact material in which an alloy containing 1 to 10 at% of one or more types of Ir is internally oxidized, and Au.

It was revealed that Pt, Pd, Rh, Ru, Os, and Ir have the effect of improving corrosion resistance when added at 1 at% or more, but when added to 10 at%, the effect of internal oxidation is impaired.

For light-load contacts for communications, the carrying current is less than 1 ampere, and they are rarely opened or closed while energized, so the important properties required are anti-adhesive properties, contact resistance properties, anti-discharge and wear-out properties, and corrosion resistance. It is.

Alloys in which 1 to 17 at% of one or more of Si and Ge are added to Ag, and 1 to 17 at% of one or more of Si and Ge to Ag
Au and Pt are added as sub-additional elements.

1 to 10a of one or more of Pd, Ph, Ru, Os, Ir
The contact material made by internally oxidizing the alloy with t% addition in the temperature range from 250℃ to the eutectic temperature has excellent adhesion resistance, contact resistance characteristics, discharge wear resistance, and corrosion resistance, and is suitable as a contact material for light-load communications. It is a close to ideal contact material.

However, contact materials for medium currents carry a current of 1 ampere to several tens of amperes, and open and close during energization.

This often causes arc discharge and welding of contacts.

Electrical contact materials which are internally oxidized by adding 1 to 17 at% of one or more of Si or Ge to Ag, and 1 to 17 at% of one or more of Si or Ge to Ag and further adding Au as a sub-additional element.
.

One or more of Pt, Pd, Rh, Ru, Os, and Ir.

When a contact material with 1 to 10 at% added and internally oxidized is used as a medium current contact, it is better than Ag, but
There are some problems with welding resistance, and welding may cause problems that cannot be separated.

In order to improve the welding resistance of the above contact material, we further investigated the addition of sub-additional elements.

The present invention incorporates at least one of Si and Ge in Ag at a lat% or more that has an internal oxidation effect and a hot processable 17at%
Hereinafter, Au, Pt, Pd, Rh, Ru.

lat containing one or more of Os and Ir for corrosion resistance.

% or more and 10 at% or less without impairing the internal oxidation effect, and furthermore, Re, Ti, and V, which are high melting point metals.

1 to 5 at% of one or more of W, Ta, Mo, Nb, and Zr
By adding and applying internal oxidation treatment, anti-adhesive properties,
Contact resistance characteristics, discharge and wear resistance characteristics, and corrosion resistance.

The object of the present invention is to provide an electrical contact material that maintains its properties and has significantly improved welding resistance.

In the above description, the anti-adhesive property refers to 5×1O-10Tor after creating a clean surface by argon ion bombardment.
Adhesion coefficient (separation force/contact force) in ultra-high vacuum at r.

Let us express it as

The contact resistance characteristic is expressed as the contact resistance after mounting the contact material on a wire spring relay and driving it 2 million times under no-load conditions in the atmosphere.

What is the discharge wear resistance characteristic?The contact material is mounted on a wire spring relay, and an RC discharge circuit with an applied voltage of 48V (R = 200
．． C=0.22 μF) to generate a discharge when closed, and the wear depth of the anode is expressed as the depth of wear of the anode after opening and closing 100,000 times.

Corrosion resistance refers to the contact material being exposed to 10 ppm H2S or SO2.
The contact resistance is expressed when a hemispherical gold rivet with a radius of 0.5 mm is statically contacted with a contact force of 5 g after being left in artificial air containing 90% humidity for 3 hours.

The welding resistance is expressed by the presence or absence of failure to open due to welding after 104 opening/closing operations when the contact material is subjected to opening/closing operations while 30 V and 30 A current is applied.

The effects of Re, Ti, V, W, Ta, Mo, Nb, and Zr will be shown by representative examples.

Example 1 An alloy having the composition shown in Table 1 was melted at 1,500 to 20,002°C to produce an ingot of 10 mmφ x 100 mm. After face cutting, it was hot worked at 600°C and processed into a 2 mm thick plate material. It was made into a contact piece of 5 mmφ x 1 mmt by cold working.

This was heated to 800℃ in the atmosphere. Internal oxidation treatment was performed for 30 minutes to obtain an electrical contact material according to the present invention.

This was adhered to a Cu rod of 5 mrnφ x 10 mm using silver solder, and opened and closed while being energized with an applied voltage of 30 V and a current of 30 A.

Six contacts were tested for each sample, and Table 1 shows the number of opening/closing operations in which half of the three contacts failed to open due to welding.

When examining the welding of Ag and Ag-10%Si internal oxidation alloy using the same test method, welding of Ag alone was 10% within 103 times.
0%, and 50% of the Ag-8i internally oxidized alloys showed non-releasable failure due to welding, so the welding resistance of the material of the present invention was improved by more than 10 times.

These contact materials also have anti-stick properties, contact resistance properties,
Maintains discharge wear resistance and corrosion resistance.

Example 2 An alloy having the composition shown in Table 2 was melted in an arc melting furnace with a diameter of 20 mm.
×5mmt button shape, hot worked at 600℃ to form a 2mm thick plate material, cold worked to 5mrIL
Make it into a shape of φ×1 mmt.

After internally oxidizing this at 700°C, C
It was adhered to the rod of U using silver solder, and the welding resistance was examined by opening and closing the wire while applying an applied voltage of 30 .ANG. and a current of 40 A.

As a result, Ag and Ag-10at%Si internally oxidized alloys were 100% welded in 103 times, whereas the contact materials shown in Table 2 were not welded at all.

These contact materials also maintain adhesion resistance, contact resistance characteristics, discharge wear resistance, and corrosion resistance.

Representative examples include Ag-8i series, Ag-8i-Au series, and A
, Re, Ti for the g-Ge-Pd system.

Although the effects of V, W, Ta, Mo, Nb, and Zr were shown, A
g-Ge system, Ag5i-Pd system, Ag-Ge-Au system,
Similar effects are obtained for Ag-8i-Ge-Au-Pd and others.

As explained above, Re is a high melting point metal.

By adding one or more of Ti, V, W, Ta, Mo, Nb, and Zr, one or more of Si and Ge can be added to 1 to 17
A silver-based eutectic alloy containing at% of Au, Pt, Pd, Rh, and Ru as sub-additional elements.

Since the melting point of a silver-based eutectic alloy to which 1 to 10 at % of one or more of Os and Ir is added is increased, there is an advantage of improved welding resistance.

Re, Ti, V, W, Ta, Mo, Nb, Z
The reason why the amount of one or more types of r added is limited to 1 to 5 at% is that if it is less than lat%, no improvement in welding resistance can be expected.
% or more, Re and Ti are removed by internal oxidation treatment.

This is because oxides of V, W, Ta, Mo, Nb, and Zr are formed on the surface and increase contact resistance.

Claims (1)

[Claims] 1 One or more of Si and Ge at a total solute concentration of 1 to 1'7
Re, Ti, V, W, and Ta, which are high melting point metals, are added as sub-additional elements to the silver-based eutectic alloy containing at.%. Adding 1 to 5 at% of one or more of Mo, Nb, and Zr,
An electrical contact material characterized by internal oxidation. 2 One or more of Si and Ge at a total solute concentration of 1 to 17
Au as a sub-additional element to the silver-based eutectic alloy containing at,%
, Pt, Pd, Rh, Ru, Os, Ir.
~10 at% is added, and Re, Ti, and V, which are high melting point metals, are added as minor additive elements. 1 to 5 of one or more of W, Ta, Mo, Nb, and Zr
An electrical contact material characterized by adding at.% and internally oxidizing the material.