JPH0410318A - Compound material for electric contact - Google Patents

Abstract

PURPOSE:To improve the spot welding strength against the base material by using the material, which is obtained by distributing Sb oxide, Te oxide, Bi oxide, and each oxide of Sn, In, Cu in Ag, as the core material, and forming an Ag alloy layer, which is obtained by adding more than two kinds of element among Sb, Te, Bi, Sn, In, Cu at a constant ratio in Ag, in the periphery of the core. CONSTITUTION:The material, which is obtained by distributing Sb oxide at 0.05-6wt.%, Te oxide and Bi oxide at 0.01-2wt.% and each oxide of Sn, In, Cu at 0.15-5wt.% in Ag, is used as the core material, and an Ag alloy layer, which is obtained by adding more than two kinds of element among Sb, Te, Bi, Sn, In, Cu at 0.01-2wt.% in Ag, is formed in the periphery of the core, and an area ratio of the Ag alloy layer which occupies in the whole of a cross-sectional area of the compound material is set at 5-40%. In the case that a ratio of the Ag alloy layer is less than 5%, covering effect against the contact base material is reduced and while spot welding and brazing to the base material is hard, and in the case that a ratio of the Ag alloy layer exceeds 40%, quantity of the covering material is too much and a problem is generated in the contact characteristic, especially in the welding-proof property. Bonding strength of Ag itself against the contact base material and the base material can be thereby improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an Ag-oxide composite material for electrical contacts, which has an Ag-oxide-based material as a core material and an Ag alloy layer formed around its outer periphery. .

[Prior art] Conventionally, Ag, Ag-Ni or A
A so-called Ag-oxide-based material is used in which oxides such as Cd, Sb, Sn, Te, and In are dispersed in Ag.

Among these, Ag-oxide contact materials are known to have excellent welding resistance, wear resistance, etc., and to be used in a wide range of applications, but they pose problems in workability and adhesive bonding to composite materials.

In other words, Cd, Sb, and Sn are present at the interface between the composite material and the contact point.
Due to the presence of oxides such as , Te, and In, the joint strength of spot welding and brazing is significantly lower than that of non-oxide materials.

Therefore, a material is being considered in which an Ag-oxide based material is used as a base material and an Ag layer is formed at the joint with the composite material or on the outer periphery of the base material to enable spot welding or brazing.

In recent years, there has been remarkable progress in rationalization and automation of machinery and equipment in various industrial fields, but as a result, equipment tends to become larger and more complex, whereas these control systems are becoming smaller and more complex. Higher frequency of operation and larger capacity are required.

In addition, due to the frequent operation of equipment, the contact surfaces of the control switches are heated to high temperatures that melt locally due to arc heat and Joule heat during opening and closing, and when the equipment is not operating, the temperature drops to room temperature. As a result, thermal cycles of high and low temperatures are repeated.

[Problems to be Solved by the Invention] When Ag-oxide contact materials are used under these circumstances, they are repeatedly subjected to frequent expansion and contraction, and complex stress is intensively applied to the inside of the contacts. Since an arch-like curved deformation occurs that makes the surface of the contact concave, the Ag layer provided to enable spot welding and brazing is peeled off at the interface with the contact base material or composite material. subject to strong stress.

This, combined with the low mechanical strength of Ag itself, causes many problems in the bonding strength with the contact base material and composite material. In other words, during use, the contact performance of the Ag-oxide material cannot be fully demonstrated, and phenomena such as separation between the contact base material and Ag or composite material occur, which develops into abnormal wear. These improvements are desired.

[Means for Solving the Problems] The present invention includes 0.05 to 6 wt% of Sb oxide, 0.01 to 2 wt% of Te and Bi oxide, and 0.05 to 6 wt% of Sb oxide in the Ag layer.
．． 05～5imt! A material in which Sn, In, and Cu oxides are dispersed is used as a core material, and S in Ag is used as a core material on the outer periphery.
b, A containing two or more of the following elements: Te, Bi, Sn, In, and Cu in a range of 0.01 to 2 wt%.
It is characterized by forming an Ag alloy layer and having an area ratio of the Ag alloy layer to the entire cross-sectional area of the composite material of 5 to 40χ.

In addition, 0.05 to 6 wtχ Sb oxide in Ag,
0.01-2 w tX of Te and Bi oxides and 0
．． Each oxide of Sn, In, and Cu of 0.05 to 5 wt.
A material in which 01~htχ is dispersed is used as a core material, and Sb, Te, Bi, Sn, In, Cu in Ag is placed on the outer periphery of the core material.
An Ag alloy layer is formed by adding two or more of the following elements in a range of 0.01 to 2 ivtχ, and the area ratio of the Ag alloy layer to the entire cross-sectional area of the composite material is 5 to 40χ. It is characterized by

In addition, the reason why the amount of Sb oxide dispersed in Ag was limited to 0.05 to 6wtχ in the above is 0.05wt!
This is because if it is less than 6wtχ, the cleaning effect due to the arc generated during opening and closing cannot be expected, and if it exceeds 6wtχ, the amount of consumption and scattering due to the arc may actually increase.

In addition, the amount of Te and Bi oxides is 0.01 to 2w tX
The reason for this limitation is that if it is less than 0.01 wt%, it is not possible to improve the adhesion resistance by adding Te and Bi oxides, and if it is added more than 2 wt%, the workability will be significantly reduced, making it difficult to mass-produce when processing as contacts. This is because gender is an issue.

Furthermore, the lower limit of the amount of oxides of Sn, In, and Cu is set to 0.
The reason why it was limited to 05-tz is that if less than this amount is added, Te
This is because a synergistic addition effect with Bi cannot be expected.
This is because addition of more than 5wtχ deteriorates contact characteristics, particularly contact stability.

Further, if Fe and Ni are added in an amount less than 0.01 wtχ, there is no effect of grain refinement, and if added in an amount exceeding 1 wtχ, the effect on other properties such as increased electrical resistance becomes large.

On the other hand, regarding the Ag alloy formed on the outer periphery of the contact base material, Sb
, Te, Bi, , Sn, In, and Cu, the range in which two or more of the following elements are added is limited to 0.01 to 2 wt%. The reason is that the amount of the added elements is O, Oht! This is because if the addition amount is less than 2 wtX, the effect of improving mechanical strength and the diffusion of elements into the Ag matrix will be weak, and an increase in composite strength cannot be expected. This is because when it becomes thin and is combined with a core material, scale may form on the surface depending on the heating atmosphere during the combination, making the combination difficult.

In addition, if the ratio of the Ag alloy layer to the cross section of the composite wire or strip is less than 5z, the coating effect on the contact base material will be small and spot welding or brazing to the composite material will be difficult, and if the ratio exceeds 40χ, the coating material This is because if the amount is too large, problems will arise in the contact properties, particularly in the welding resistance.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

First Example Ag-(0,l5b-0,6Te-0,
2Bi-5Sn-11n-2Cu)O, each -tχ wire rod with a thickness of 1,5m+n produced by drawing process
Ag-0,4Sb-0,05Te-0,15Bi-0
, 1Sn-0, 11n-0, 1Cu8wtχ pipes were fitted and brought into close contact, heated to 700°C, and composited by drawing.

This wire was heated at 650° C. for 4 hours in an inert atmosphere to cause mutual diffusion between the core material and the peripheral material.

This was repeatedly annealed and drawn in an inert atmosphere to obtain a wire rod with a diameter of 3 mm.

Second embodiment 8g-(ISb-1,5Te-0,3B) with a diameter of 13 mm
i-ISn-IIn-5Cu)0.8wtχ wire,
Ag-0.2 with a thickness of 1 mm made by drawing process
Sb-0, lTe-0, lB1-0.3Sn-0,05
Fit and tightly fit the I n @ w tχ pipe, 700
It was heated to "C" and composited by drawing.

This wire rod was heated at 650° C. for 4 hours in an inert atmosphere to cause mutual diffusion between the core material and the peripheral material. This was repeatedly annealed and drawn in an inert atmosphere to obtain a wire rod with a diameter of 3 mm.

Furthermore, the third to sixth examples shown in the table below were manufactured using substantially the same method as the first example and the second example.

After cutting each of the wire rods of each of the above examples into lengths of 2.5 mm, they were spot welded to a composite material, the shear joint strength was measured, and the wires were assembled into a commercially available contactor at a voltage of 220 V, a current of 78 A, and a power factor of 0. The implementation test was conducted on 35 and is shown in the table below.

Note that for comparison, results obtained using the following prior art are listed.

First Conventional Example A 1 mm thick Ag pipe produced by drawing was fitted and tightly attached to an Ag-12 round tχCdO wire rod with a diameter of 13 mm, heated to 700° C., and composited by drawing.

This wire was repeatedly annealed and drawn to a diameter of 3 mm.
A wire rod was obtained.

Second Conventional Example A 0.5 mm thick Ag pipe produced by drawing was fitted and tightly attached to a wire rod of Ag-10xCdO with a diameter of 13 mm, heated to 700'C, and composited by drawing.

This wire was repeatedly annealed and drawn to a diameter of 3 mm.
A wire rod was obtained.

This test revealed that in the present invention, it is more effective when the number of elements added to the core material serving as the contact base material and the added element to the Ag alloy formed on the outer periphery are the same.

[Effects of the Invention] According to the present invention described above, as shown in the table, the spot welding strength with the composite material is excellent, and extremely excellent effects are shown in the contact opening/closing test using an actual machine.

Claims (1)

[Claims] 1. 0.05 to 6 wt% Sb oxide in Ag, and 0.05 to 6 wt% Sb oxide in Ag;
．． 01-2 wt% Te and Bi oxides and 0.05
The core material is a material in which ~5wt% of each oxide of Sn, In, and Cu is dispersed, and around the core material, Sb, Te, and B are dispersed in Ag.
0.0 or more of each element of i, Sn, In, Cu
A composite material for an electrical contact, characterized in that an Ag alloy layer is formed in an amount of 1 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%. 2. 0.05 to 6 wt% Sb oxide in Ag and 0.05 to 6 wt% Sb oxide
．． 01-2 wt% Te and Bi oxides and 0.05
~5wt% of each oxide of Sn, In, and Cu and further Fe
or 0.01 to 1 oxide of one or both of Ni
A material in which wt% was dispersed was used as a core material, and two or more of the elements Sb, Te, Bi, Sn, In, and Cu were added to the outer periphery of the Ag in a range of 0.01 to 2 wt%. A composite material for electrical contacts, characterized in that an Ag alloy layer is formed, and the area ratio of the Ag alloy layer to the entire cross-sectional area of the composite material is 5 to 40%.