JPS58104147A - Electrical contact material - Google Patents

Abstract

PURPOSE:To obtain an electrical contact material having improved characteristics as a material for a slide switch by adding specified amounts of Bi and In oxides to an Ag-In or Ag-Cu alloy matrix. CONSTITUTION:This electrical contact materal is obtd. by dispersing 0.5-3wt% as Bi of Bi2O3 and 0.5-5% as In of In2O3 in an Ag-In alloy matrix contg. 3-20% In or an Ag-Cu alloy matrix contg. 1-10% Cu. The contact material has superior sliding characteristics and sufficient resistance to dissipation due to arc, and it has superior characteristics as a material for a slide switch such as high weldability to a spring material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite electrical contact material in which a metal oxide is added to an Aq alloy matrix.
The present invention aims to provide an electrical contact material that is optimal for use in slide switches that open and close alternating current (AC) loads with a steady current of 0 A and up to about 3 A.

As a composite electrical contact material using metal oxide, Aq
-CdO contact materials are widely used, and recently,
Ag-SnO2-based materials have also become available.

However, in recent years, various switches for electronic devices have been required to be easier to operate and more compact in order to improve contact reliability in accordance with safety regulations and to improve ease of use. There has been a tendency to switch on and off loads up to several amperes. As a result, spring materials that have been frequently used as contact materials for slide switches, such as phosphor bronze (Sn7-9% by weight Po, 03-o
, 35% by weight balance Cu) and Aq laminated to a thickness of 2 to 10 μm, it is difficult to obtain sufficient life characteristics due to wear due to arcing. On the other hand, for arc consumption, the above-mentioned Aq-Cdo, Aq-8
N02-based materials are desirable, but they have problems with mechanical sliding properties, and are difficult to use as material for slide switches because they are laminated onto spring materials and processed into the desired thickness by rolling, etc. Difficulties were recognized.

In view of the above points, the present invention basically consists of Aq-In
Alloy < is an attempt to improve the characteristics of slide switches by proposing a material in which an oxide containing Bi2O3 as a main component is dispersed in a matrix made of an Ag--Cu alloy.

Already, the inventors have found that Bi2O3 in ~matrix
In addition, materials in which oxides such as In2O3 are dispersed have been proposed. These materials, like Ag-CdQ, exhibit excellent properties against welding and arc wear, but
The sliding properties do not necessarily show a satisfactory tendency. Furthermore, it is not a material that can be easily attached to the spring material.

However, on the other hand, since it is composed of an oxide with a lower vapor pressure than ld and CdO, there are fewer defects in the bonding layer during bonding, or B12o3, which has a low hardness as an oxide, is used. It has advantages such as being relatively easy to process and being able to spread to some extent.

The present inventors investigated methods for improving sliding properties, methods for laminating spring materials, and maintaining arc properties necessary and sufficient as materials for slide switches for materials with such characteristics. is added to form a matrix of A9-In alloy and Ag-Cu alloy, and to this, Bi2O3 and In2O
It has been found that a material in which No. 3 is uniformly dispersed can achieve the intended purpose.

Next, the electrical contact material of the present invention will be explained in detail.

The electrical contact material of the present invention contains oxides of Bi and In at least in an Aq-In or Aq-α alloy matrix. These oxides have at least a tendency to form complexes.
Although it exists as a lid alone, the melting point of Bi2O3 is usually 8.
1, even though the temperature is around 20°C. 203. Og! , □9□ and ka8. . . ,. Wow, there is a tendency for □ to rise, and it is presumed that there is some kind of mutual reaction.

The electrical contact material of the present invention has the above-mentioned structure, and the content of these constituent materials is such that the weight ratio of all metal elements in the material is such that the metal oxide is 0.5 Bi in terms of metal equivalent value. ~
The alloy matrix part contains 3 to 20% by weight of In in the case of Ag-In alloys and C in the case of Ag-Cu alloys.
u is 1 to 10% by weight, and the remainder is made up of gradients.

In the electrical contact material of the present invention, the Ag--In alloy or Ag--Cu alloy constituting the phantom alloy matrix improves sliding properties for use in slide switches and reduces mechanical wear.

Effective in preventing adhesion and reducing frictional force. In addition,
When bonding to a spring material, a thermocompression bonding method is usually used, but oxide-containing materials have a weak bonding force, and the adhesive layer often peels off during the subsequent rolling process. Here, a Cu layer or a layer of Cu and In is inserted between the material of the present invention and the spring material as a bonding metal layer, and this is heated under controlled atmosphere to create a bond between the material and the matrix alloy of the present invention. The resulting eutectic melting of Ag-Cu-In causes the bonding metal layer to undergo liquid phase diffusion, resulting in an adhesive layer with fewer defects. The lower limit of the amount of In or Cu added in the Aq alloy matrix is determined by the minimum amount to bring out the above-mentioned effects. On the other hand, its upper limit is limited by mechanical processability or contact resistance characteristics.

Next, the oxide contained in the electrical contact material of the present invention will be explained. The oxides contained are the aforementioned Bi and In oxides. These oxides appear to exist mostly in their own form.

B12O3 contains trace amounts of other oxides to
-Bi2O3, the melting point rises and the material has a sublimation point within 100''C, showing an improvement effect on welding of contacts.

Considering the change in the melting point of Bi2O3 in the electrical contact material of the present invention, it is thought that In2O3 exerts some kind of action to cause the behavior of B12O3 to appear. On the other hand, since Bi2O3 alone does not have sufficient resistance to ac consumption, thermally stable In20
Since the addition of s has adverse effects such as an increase in contact resistance and a deterioration in machinability, consideration must be given to the addition amount KVi.

Ag-In, Aq-Cu alloy matrix, B
As a method for dispersing oxides of i and In, Aq
A so-called internal oxidation method is used to create an alloy powder in which Bi and In are added, and this is heated in an oxidizing atmosphere to selectively oxidize Bi and In. The prepared A(J-In powder or ~-Cu
Powders are added, homogeneously mixed, molded, and sintered, and In or Cu is diffused into the matrix to obtain an Aq alloy matrix, in which oxides are dispersed.

In materials produced by such methods and configurations,
The composition ratio of the metal elements to be converted into oxides was determined under the conditions described above, and was Bi.

Each minimum amount of In is the lower limit at which the addition effect is recognized for the intended use of the material V according to the present invention, and each maximum amount is the lower limit for laminating the spring material. The amount is limited by the possibility or processability such as rolling or bending and punching as a slide switch contact.

The electrical contact material of the present invention described above will be described in more detail based on Examples.

According to the composition of the invention, Ag, In, Cu,
A total amount of 5ooy Bi was weighed. Aq is converted into an oxide, and is divided into an amount in which both Bi and In can be dissolved as a solid solution, and an amount in which the remaining matrix is used as an alloy with In and Cu. When the matrix is an Ag-In alloy, In is also divided into oxide and matrix. For example, in the case of the movable contact material of sample L6 shown in the following table, the matrix is 1
An Ag--In alloy containing 0% by weight of In, and 3% by weight of Bi in terms of metal.

Since it contains 2% by weight of Inf, the respective weight values are 1sy for Bi and 10y for In for oxide.

A total of 609 and Aq426y for matrix use.

Let it be y. Here, 275y of Ag 425y is separated, B115p and In10y for oxide are added and melted, and a molten metal spraying device using pressurized nitrogen gas is used to prepare a powder for internally kneaded alloy. Powdered at 60-32
The alloy powder should be approximately 1.5 mesh. This powder is Too''
After the heat treatment in the atmosphere, an internally oxidized alloy powder is obtained in which Bi and In in the Aq matrix are selectively oxidized. On the other hand, Aq (D remainder 160y and In50F for the matrix are melted in the same way and then turned into Ag-In alloy powder using a molten metal spraying device. The above description has been made using the En 6 sample as an example, but the same applies to other samples as well. After these powders are homogeneously mixed, they are loaded into a cylindrical mold with a diameter of 30 m/m and molded with a pressure of 4 tons/ctrl.The molded billet is heated in a nitrogen gas atmosphere. It is sintered at 600'C-800°C.In this case, the matrix part flows out, so it is assigned to the temperature increase gradient and molded again under the condition of 8 tons/cd of In in the internal oxidized powder matrix. Afterwards, it is sintered and heat-treated under the same conditions as the previous time.Then, this sintered body has a 560 to 600
By warm extrusion of ``C, 3 Q m/m diameter to width 2
Processed into a plate shape with a thickness of 0m7Δ and a thickness of 3m. moreover,
After cold rolling to a thickness of 1 meter, the surface is polished and cleaned using Scotch prite. On the other hand, an 8 wt. Apply to a thickness of 20μ, and then apply C
Apply 10 to 20μ of In plating on top of U plating. In addition, C
U plating can be omitted when the Cu composition of the matrix is 8% or more. Then, the 1m/In thick oxide processed earlier -
After stacking the Aq alloy plate on the In-plated surface and adhering it tightly using a heat-resistant jig, heat the plate at 660°C to 75°C in a nitrogen gas atmosphere.
Heat treated at 0''C for 1 hour and pressure bonded.At this time, Cu, I
Each plating layer of n undergoes liquid phase diffusion, but ~-In or #
-Cu matrix In.

It has a synergistic effect with Cu, and a bonded state with few defects can be obtained. Finally, this bonding material is processed to a thickness of 70 μm by repeating annealing and rolling.

The material obtained as described above was molded into a movable side contact of a slide switch and was used for characteristic evaluation.
In addition, the fixed side contact of the test slide switch is as follows:
A material made of a 0.6 fF+ brass plate plated with a 2μ thick plate was used, and a contact lubricant made from synthetic oil, which is commonly used in slide switches, was applied to the plated surface.

As samples for comparison of characteristics, we prepared a phosphor-backed copper contact with a total thickness of 70 μm in which a 7 μm thick plate was attached to the movable contact, and a slide switch using the same material and lubricant as above for the fixed contact.

The switch was evaluated with a capacitor load, AC30V,
The test was conducted by opening and closing a load circuit of 3A steady state and 30A inrush 20,000 times, and then observing the contact resistance and wear and tear of the contacts. The results are shown in the table below.

(Hereafter, extra white) ,)゛.

As is clear from the results in the table, the electrical contact material according to the present invention exhibits practically sufficient characteristics even after the operation test. In addition, less consumption and wear of materials leads to improved insulation between switch contacts, which is also favorable in terms of safety.

On the other hand, Aj! is currently widely used. In the case of single material,
Due to arc consumption, the phosphor bronze surface of the spring material is exposed,
Some of them have holes in the phosphor bronze surface.

As explained above, the electrical contact material of the present invention makes it possible to expand the switching load of a slide switch to the arc generation area, and its practical value is extremely high.

Claims (1)

[Claims] fl) A metal oxide is dispersed in an Aq alloy matrix, and the metal oxide contains 0.5 to 3% by weight of Bi and 0.5 to 5% by weight of In. , and further contains 3 to 20 In as the Aq alloy matrix component.
(2) A metal oxide is dispersed in an Aq alloy matrix, and the metal oxide is converted into a metal equivalent value, and Bif
:0.5 to 3% by weight, contains 0.5 to 5% by weight of In, and further contains 1 to 10% of Cu as the auxiliary alloy matrix component.
Electrical contact material 0 characterized by containing % by weight and the remainder being gradient