JP2884533B2 - Composite materials for electrical contacts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention uses an Ag-oxide-based material as a core material,
The present invention relates to a composite material for an electrical contact using an Ag-oxide system having an Ag alloy layer formed thereon.

[Conventional technology]

Conventionally, Ag, Ag-Ni or Ag
Materials in which oxides such as Cd and Sn are dispersed are used.

Among them, Ag-CdO-based alloys are known for their excellent welding resistance, wear resistance and the like, and are known to have a wide range of use. However, they have problems in workability and adhesion bonding to a base material.

That is, since an oxide such as CdO exists at the interface between the base material and the contact, the joining strength by spot welding or brazing is remarkably low as compared with a non-oxide-based material. Therefore, Ag-
A material in which a CdO-based material is used as a base material and an Ag layer which enables spot welding or brazing on a joint with the base material or an outer periphery of the base material is considered.

In recent years, rationalization and automation of mechanical devices in various industrial fields have been remarkably developed, but with this trend, devices are becoming larger and more complex, but these control systems are rather smaller, High frequency operation and large capacity are required.

In addition, with the frequent operation of the equipment, the contact surface of the control switch is heated to a high enough temperature to melt locally during operation due to arc heat and Joule heat accompanying opening and closing, and drops to room temperature when stopped. Therefore, the high-temperature and low-temperature thermal cycles are repeated.

[Problems to be solved by the invention]

When using the Ag-oxide based contact material under such circumstances, frequent expansion and contraction will be repeated, complex stress will be intensively applied inside the contact, and the contact surface will be concave. Since an arcuate curved deformation occurs, the Ag layer provided to enable spot welding and brazing receives a strong stress that peels off at the interface with the contact base material or the base material.

This causes many problems in the bonding strength between the contact base material and the base material in combination with the low mechanical strength of Ag itself. That is, while the contact performance of the Ag-oxide-based material cannot be sufficiently exhibited during use, a phenomenon such as separation of the contact base material and Ag or the base material occurs, which causes abnormal wear. These improvements are desired.

[Means for solving the problem]

The present invention relates to a method for producing Cd oxide of 1 to 12 wt% in Ag,
2 wt% of Te and Bi oxides and 0.05 to 5 wt% of Sb, Sn, I
The core material is a material in which each oxide of n and Cu is dispersed, and in the outer periphery, two or more of each element of Cd, Te, Sb, Bi, Sn, In, and Cu are contained in an amount of 0.01 to 2 wt% in Ag. %, And the area ratio of the Ag alloy layer to the entire cross-sectional area of the composite material is 5 to 40%.

Also, 1 to 12 wt% Cd oxide in Ag and 0.01 to 2 wt%
% Te and Bi oxides and 0.05-5 wt% of Sb, Sn, In, C
The core material is a material in which each oxide of u and one or both oxides of Fe or Ni are dispersed at 0.01 to 1 wt%, and Cd, Te, Sb, Bi, Sn, In , To form an Ag alloy layer in which at least two of the Cu elements are added in the range of 0.01 to 2 wt%, and the area ratio of the Ag alloy layer to the entire cross-sectional area of the composite material is 5 to 40%. There is a feature.

In the above, the amount of Cd oxide dispersed in Ag is 1
The reason why the amount is limited to 1212 wt% is that if it is less than 1 wt%, the cleaning effect due to the arc generated at the time of opening and closing cannot be expected, and if it exceeds 12 wt%, the amount of scattered consumption by the arc may rather increase.

The reason why the content of Te and Bi oxides is limited to 0.01 to 2% by weight is that if less than 0.01% by weight, it is not possible to improve the welding resistance by adding Te and Bi oxides. Is significantly reduced, and mass productivity at the time of processing as a contact becomes a problem.

Further, the lower limit of the amount of oxides of Sb, Sn, In, and Cu is set to 0.05 wt.
The reason why the amount is limited to 0.1% is that a synergistic addition effect of Te and Bi cannot be expected if the addition is less than this, and if the addition exceeds 5 wt%, contact stability, especially contact stability, is deteriorated.

In addition, the addition of Fe and Ni has no effect of refining the crystal grains when the addition is less than 0.01 wt%, and the addition of more than 1 wt% has a large effect on other characteristics such as an increase in electric resistance.

On the other hand, for the Ag alloy formed on the outer periphery of the contact base material, Cd,
The reason why the range of adding two or more of the elements Te, Bi, Sb, Sn, In, and Cu is limited to 0.01 to 2 wt% is as follows. This is because the effect of diffusion of elements into the Ag matrix is small and the composite strength cannot be expected to increase. This is because, in the case of compounding with a mixed core material, scale is generated on the surface depending on the heating atmosphere at the time of compounding, and compounding becomes difficult.

If the ratio of the Ag alloy layer to the cross section of the composite wire or strip is less than 5%, the effect of coating the contact base material will be small, and spot welding or brazing to the base material will be difficult. This is because the amount of the material is too large, which causes a problem particularly in the welding resistance among the contact characteristics.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Example Ag- (1Cd-0.1Te-4Sb-2Bi-1.5Sn-2In 13 mm in diameter
The -0.2Cu) O _x each wt% of the wire, the thickness of 1.5mm produced by drawing Ag-0.1Cd-0.1Te-0.05Sb- 0.05Bi-
A pipe of 0.1 Cu each wt% was fitted and adhered, heated to 700 ° C., and composited by drawing.

The wire was heated at 650 ° C. for 4 hours in an inert atmosphere to mutually diffuse the core material and the outer peripheral material.

This was repeated annealing and drawing in an inert atmosphere to obtain a wire having a diameter of 3 mm.

Second Example Ag- (8Cd-0.05Te-0.5Sb-0.05Bi-2Sn having a diameter of 13 mm
-0.5In-1Cu-0.2Ni) O _{x 1} wt% Ag-0.3Cd-0.05Te-0.15Bi with 1mm thickness produced by wire drawing
-0.2Sn-0.1In Each wt% pipe is fitted and adhered, 700 ℃
And composited by drawing.

The wire was heated at 650 ° C. for 4 hours in an inert atmosphere to mutually diffuse the core material and the outer peripheral material. This was repeated annealing and drawing in an inert atmosphere to obtain a wire having a diameter of 3 mm.

Further, third to sixth examples shown in the following table were produced in substantially the same manner as in the first and second examples.

After cutting each wire rod of each of the above examples to a length of 2.5 mm,
Spot welding to the base material, measuring the shear joint strength and incorporating it into a commercially available contactor, voltage 220V, current 78A,
A mounting test was performed with a power factor of 0.35, and is shown in the table below.

In addition, the result by the following prior art is shown for comparison.

First conventional example A 1.5 mm thick Ag pipe made by drawing was fitted and tightly fitted to a 13 mm diameter Ag-12 wt% CdO wire rod.
It was heated to 00 ° C and composited by drawing.

Annealing and drawing of this wire are repeated to create a diameter of 3 mm.
Was obtained.

Second conventional example A 0.5 mm thick Ag pipe made by drawing was fitted and adhered to a 13 mm diameter Ag-18 wt% CdO wire,
The mixture was heated to ℃ and composited by drawing.

Annealing and drawing of this wire are repeated to create a diameter of 3 mm.
Was obtained.

From this test, it was found that, in the present invention, it is more effective to increase the number of the same elements as the additive element of the core material serving as the contact base material and the additive element of the Ag alloy formed on the outer periphery.

[Effects of the Invention] According to the present invention described above, as shown in the table, the spot welding strength to the base material is also excellent, and a very excellent effect is exhibited in the contact switching test using an actual machine.

Continuation of the front page (56) References JP-A-63-149341 (JP, A) JP-A-64-65203 (JP, A) JP-A 1-268831 (JP, A) JP-A 1-108331 (JP) JP-A-58-110639 (JP, A) JP-A-58-107440 (JP, A) JP-A-59-215443 (JP, A) JP-A-60-248806 (JP, A) 51-62356 (JP, A) JP-A-53-88954 (JP, A) JP-A-59-215442 (JP, A) JP-A-3-215640 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01H 1/00-1/04 C22C 5/06

Claims (2)

(57) [Claims] (1) a silver (Cd) oxide of 1 to 12 wt% in Ag;
2 wt% of Te and Bi oxides and 0.05 to 5 wt% of Sb, Sn, I
The core material is a material in which each oxide of n and Cu is dispersed, and in the outer periphery, two or more of each element of Cd, Te, Sb, Bi, Sn, In, and Cu are contained in an amount of 0.01 to 2 wt% in Ag. %, Wherein the area ratio of the Ag alloy layer to the entire cross-sectional area of the composite material is from 5 to 40%. 2. The method according to claim 1, wherein the Cd oxide is 1 to 12 wt% in Ag, and 0.01 to 12 wt%.
2 wt% of Te and Bi oxides and 0.05 to 5 wt% of Sb, Sn, I
The core material is a material in which each oxide of n and Cu and one or both oxides of Fe or Ni are dispersed at 0.01 to 1% by weight, and Cd, Te, Sb, Bi, Sn in Ag on the outer periphery thereof. , In, and Ag containing two or more of the elements added in the range of 0.01 to 2 wt%.
A composite material for an electrical contact, wherein an alloy layer is formed, and an area ratio of an Ag alloy layer to the entire cross-sectional area of the composite material is 5 to 40%.