JPS5867838A - Electric contact material - Google Patents

Abstract

PURPOSE:To make it possible to magnify the switch load of a slide switch to an arc generating region, by dispersing oxides of Bi and Sn in an Ag alloy comprising a specific amount of Ag and In in a specific amount. CONSTITUTION:In an Ag alloy consisting of, on the basis of wt%, 3-20 In and the remainder Ag, oxides of Bi and Sn are dispersed. These oxides are dispersed as Bi2O3 and SnO2 but the amounts thereof are adjusted to, on the basis of wt%, 0.5-3 Bi and 0.5-4 Sn as metals. Other than these oxides, in order to reduce consumption due to arc, 0.5-2 In oxide expressed in terms of metal be arbitrarily added and dispersed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical contact material in which metal oxides are dispersed in a waste matrix. The present invention provides an electrical contact material suitable for use in slide switches that open and close loads.

Mug-C is a composite contact material using metal oxides.
(50 contact materials are widely used, and recently 5g-
8nO2-based materials have also come into use.

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 is a growing tendency to open and close loads up to several micrometers. As a result, spring materials 1, such as phosphor bronze (Sn 7-9% by weight, P 0.03-0), have been widely used as contact materials for slide switches.
．． In the case of a material in which Mug is laminated to a thickness of 2 to 1 μm to 35% by weight (the balance is On), sufficient life characteristics cannot be obtained due to wear due to arcing. On the other hand, for arc consumption, the above-mentioned Mu-y-3.

CdO, Mu (1-8n02 material) is desirable, but it has problems with mechanical sliding and dynamic properties, and when used as a material for slide switches, it is pasted onto a spring material and then rolled. Although it was processed to the desired thickness, a difficulty was recognized in this point.

The present invention has been made in view of the above-mentioned points, and basically provides a material in which an oxide containing BizO3 as a main component is dispersed in a matrix made of a fl -I n alloy, and is used to create a slide switch. This is an attempt to improve the characteristics.

The applicant has already developed Bi2 during the multi-IJ class.
We proposed a material in which oxides such as 5n02 and In2O3 are dispersed in an O3 pond. These materials are
.

Although it shows excellent properties in terms of welding resistance and arc wear similar to the above, it does not necessarily show a tendency to be satisfactory in terms of sliding properties. Furthermore, it is not yet a material that can be easily attached to spring materials. However, on the other hand, since it is composed of an oxide with a lower vapor pressure than CdO, there are fewer defects in the bonding layer during bonding, or B has a low hardness compared to CdO.
Since it contains 12O3, it has advantages such as relatively good processability and ability to be spread to a certain extent.

The present inventors investigated methods for improving the sliding properties of materials with such characteristics, methods for laminating them with spring materials, and maintaining arc properties necessary and sufficient as materials for slide switches. As a result, the inventors added In to the mug matrix. Bi2 is added to form a Mu9-In alloy matrix, and Bi2
Disperse O3 and SnO□ or further In
It has been found that the intended purpose can be achieved by adding 2O3 to the material.

Next, the above-mentioned material according to the present invention will be explained in detail.

The electrical contact material of the present invention contains oxides of 81 and an in a Mug-In alloy matrix. These oxides are composited into Bi28n20. , it is 0 type. and,
Depending on the composition ratio of Bi and Sn, it contains an oxide of sn, SnO2, or an oxide of Bi, Bi2O3. In addition to the above-mentioned oxides, an oxide of In is added especially in order to reduce wear due to arcing.

The electrical contact material of the present invention has the above-mentioned structure, and the content of these constituent materials is such that the In of the fl-In alloy matrix is 3 to 2 in terms of the weight ratio of all metal elements in the material.
0% by weight, each oxide is 5 to 3% by weight in terms of metal, and snO is 5 to 4% by weight.

And Mug is the remainder. When adding In oxide, it is added in an amount of 0.6 to 2% by weight in terms of metal.

In the electrical contact material of the present invention, the Mug-In alloy constituting the Mug-In alloy matrix improves sliding properties for slide switches, reduces mechanical wear, and prevents adhesion. It is effective in preventing friction and reducing frictional force.

In addition, when bonding to spring materials, thermocompression bonding is usually used, but oxide-containing materials have weak bonding force, and the adhesive layer may peel off during the subsequent rolling process.
In the case where In is added and the spring material is a Cu-based alloy, liquid phase bonding due to eutectic melting of Mu9-cu-In is observed, reducing adhesion defects in the bonding layer. The lower limit of the amount of In added in the Ag 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 by the surface contact resistance characteristics.

Next, the oxide contained in the electrical contact material of the present invention will be explained. The oxide of B1 and Sn (Bi2Sn207) contained as the main oxide is Bi minide (Bi20
By heating an oxide (SnOz) of 3) and aH at a molar ratio of 1:2 in the range of γoo'c to 900°C, an oxide having a yellow curb structure is produced. Its melting point is above 12oo0C and shows sublimation, 9I
By dispersing it in the n-alloy matrix, the effect of reducing wear due to arc is significant. As a method for dispersing the above-mentioned B1-5n oxide, or even an In oxide in the Mug9-In alloy matrix,
.

An alloy powder to which Sn and further In are added is prepared and heated in an oxidizing atmosphere to selectively oxidize Bi, Sn, and In. The so-called internal oxidation method was used to obtain internal oxidation alloy powder, and separately prepared Mu9-In powder was added to it, mixed homogeneously, and further sintered to disperse the oxide in the 5g-in alloy matrix. take the method. In this method, the B1-5n oxide is first produced in an alloy powder containing Muy as a matrix, but in order to produce the B1-8n oxide in the form of a composite oxide Bi25n207, the molarity Converting from the ratio, the Sn weight is x, S
When n weight is y, it is necessary to have a relationship of '7'z -0,67.

However, it is difficult to reliably convert Bi into the Bi25n2Q7 state during internal oxidation treatment because it tends to segregate in the Bllj alloy, and Bi oxide (B
1203), an oxide of Sn (SnOz) may be present alone in a small amount. Also, as a matter of course, if the value of y//x becomes larger than 0.67, there will be fewer chances for Bi oxide to exist alone, and the Sn acid (arsenic content) will increase.y4 It is clear that the opposite trend will occur if the value of is smaller than 0.67.However, in the case of a slide switch contact with a rather large load current, which is the application of the electrical contact material of the present invention, the above-mentioned value is larger than o, 67, and the Sn oxide is B1-5n
Low consumption as it coexists with oxides. but,
As the amount of Sn oxide increases, workability tends to deteriorate, and this tendency is particularly noticeable when In oxide is added to reduce the amount of wear. Therefore, the amount of Sn is Hiroshi = 2
It can be said that keeping it to a certain level brings overall benefits. The composition ratios of the metal components to be converted into the oxides described above were determined under the conditions described above, and include Bi,
The minimum amounts of Sn and In are the lower limits at which the addition effect is recognized for the intended use of the electrical contact material according to the present invention, and the maximum amounts of each include the possibility of bonding to spring materials, rolling or sliding. This amount is limited by the workability of bending and punching as a 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, Mug, Bi, Sn, In
Weigh out 600g of When In is included as an oxide, it is weighed separately from the amount to be included in the matrix.

Mug has an amount that can dissolve any of Bi, Sn, and In to be contained as an oxide, and the remaining I for the matrix.
Separate for alloys with n. For example, sample No. shown in the following table,
In the case of material for movable contacts in item 7.

The matrix is a Mug-In alloy containing 10% by weight of In, in which 3% by weight of Bl is added in terms of metal.

Lucara contains 2% by weight of Sn and 1% by weight of In, respectively) weighing value 1dBi 15g, sn 10g.

Insy for oxide, In50 for matrix
,9. 5g and 420g for a total of 500g. Here, mug
Separate 3oog out of 420g.

Add and melt Biltsg, Sn 1og, and In 5g to this, and in order to create powder for internal oxidation alloy, powder it in a molten metal spraying device using pressurized nitrogen gas to obtain an alloy powder of about 60 to 326 mesosi. . This powder is heat-treated in the air at a temperature of 700° C. for 50 hours to become an internally oxidized alloy powder in which Bi, SH, In, etc. are selectively oxidized in the mug matrix.

On the other hand, the remaining 120 g of Mug and Rneog for matrix were melted in the same manner, and then mixed with Mug (1-In) using a molten metal spraying device.
It is considered to be an alloy powder. The above description has been made using sample No. 7 as an example, but the process is roughly the same for other samples as well. These powders were homogeneously mixed, then loaded into a cylindrical mold with a diameter of 30 m/m, and molded under a pressure of 4 tons/ctfr.

The molded billet was heated at 700'C in a nitrogen gas atmosphere.
Sintered at ~860°C.

In this case, since the IJ part will flow out, the temperature rise gradient should be taken into account and the internal oxidation treatment (internal oxidation treatment)
n diffusion is performed. The billet thus sintered is then molded again under the conditions of 460°G and 8 tons/Ca, and then subjected to sintering heat treatment under the same conditions as before. And this sintered body H, 550~e o oo
By wet extrusion of c.
Processed into a plate shape with a thickness of 3 m and 7 m. moreover,
After cold rolling to a thickness of 1 m7°, the surface is polished and cleaned using Scotch prite. On the other hand, an 8 wt % Sn phosphor bronze plate having a thickness of 9'm/rrL and a width of 30 mm is prepared as a material for the spring material, and its surface is similarly plated with Scosotibra to a thickness of 10 to 20 microns. and,
The previously processed 1TL/rrL thick oxide-Jin9 alloy plate is superimposed on the In-plated surface and brought into close contact with a heat-resistant jig, and then heat treated at 650C to 760G in a nitrogen gas atmosphere for 1 hour and pressure bonded. At this time, the In plating undergoes liquid phase diffusion, but exhibits a synergistic effect with the In in the Mut/-In matrix, resulting in a bonded state with fewer defects. Finally, this bonding material can be processed to a thickness of 70 μm by repeating annealing and rolling.

The material obtained as described above was molded into a movable contact of a slide switch and subjected to characteristic evaluation.

In addition, the fixed side contact of the test slide switch is as follows:
A brass plate with a thickness of 0.6% was coated with a 2μ thick muy plating, and a contact lubricant made of synthetic oil, which was scraped and normally used for slide switches, was applied to the mu9 plating surface. As a comparison sample of characteristics, a phosphor bronze contact with a total thickness of 7μ with a 7μ thick layer pasted on the movable contact, and a slice switch using the same material and lubricant as above for the fixed contact were evaluated with a capacitor load. The test was carried out by opening and closing a load circuit of 3oV, 3oV steady, and 30mu in run-time 20,000 times, and then observing the contact resistance and wear and tear of the contacts. The results are shown in the table below.

(Left below) 3. The gas contact material shows sufficient characteristics for practical use even after the operation test. In addition, less consumption and wear of the material leads to better insulation between the switch contacts, which is also favorable in terms of safety.

On the other hand, in the case of single material by, which is currently widely used, the phosphor bronze surface of the spring material is exposed due to arc consumption, as shown in sample No. 68, and in some cases, holes are formed on the phosphor bronze surface. There is also.

As explained above, the electrical contact material of the present invention.

It is possible to expand the switching load of the slide switch to the arc generation area, and its practical value is
'i is extremely high.

Claims (2)

[Claims] (1) An electrical contact material in which a metal oxide is dispersed in an Ag alloy matrix (IJ), in which the metal oxide contains 0.6 to 3% by weight of Bi and 0.6% to 3% by weight of Sn and 0.6% to 3% by weight of Sn. 5～
4% by weight, and further the above-mentioned mug alloy matrix component,
An electrical contact material comprising 3 to 20% by weight of In, with the remainder being mug. (2) An electrical contact material in which a metal oxide is dispersed in an I+ alloy, and the metal oxide contains 0.5 to 3% by weight of B1 and 0.5% by weight of Sn. 6～
An electrical contact material characterized in that the alloy matrix component contains 3 to 20% by weight of In and the balance is 5 g.