JPS6297213A - Electric contact material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to electrical contact materials.

[Background technology]

Various contact materials are used in electromagnetic contactors, relays, breakers, etc. These contact materials have low wear and tear;
It is required to have the characteristics of being difficult to weld and having low contact resistance. However, in reality, it is difficult to find a material that simultaneously satisfies these three properties.

In recent years, relays equipped with contacts with a relatively large current capacity have been widely used to control the input and output of circuits and equipment. When used to control input, the purpose is to control capacitive loads; when used to control output, the purpose is to control motors, lamps, etc.

As a result, a rush current flows through the contacts of the relay, causing problems such as welding of the contacts. In view of these factors, there is currently an increasing demand for electrical contact materials with good welding resistance.

However, if electrical contact materials are made with a focus on welding resistance, the conductivity will deteriorate and the contact resistance will increase when used as a contact, resulting in no improvement in the current capacity of the contact. There is a problem.

[Purpose of the invention]

In view of the above circumstances, it is an object of the present invention to provide an electrical contact material that maintains good conductivity and also has excellent welding resistance.

[Disclosure of the invention]

The present invention, which achieves the above object, provides an electrical contact material in which a layer made of a material with higher hardness than the material is provided on a layer made of a material with good conductivity.

Hereinafter, one embodiment of the electrical contact material according to the present invention will be explained with reference to the accompanying drawings. Figure 1 shows an example of the electrical contact material (hereinafter simply referred to as "contact material") of the present invention. This is a vertical cross section. The contact material 1 has a two-layer structure of an upper layer 2 and a lower layer 3. The upper layer 2 is thinner than the lower layer 3. The upper layer 2 is made of a material with high hardness and has excellent welding resistance. The lower layer 3 is made of a material with good conductivity. Since the contact surface when working as a contact is the upper layer surface 2a, this contact material 1 having a highly hard upper layer has excellent welding resistance. Moreover, since most of the thickness in the thickness direction is a region with good electrical conductivity, the electrical conductivity of the contact material 1 itself is maintained at a good value. In this way, contact material 1
Since it has excellent welding resistance and also maintains good W conductivity, it is suitable for making contacts with a large current capacity.

Next, an example of specific materials for the upper layer 2 and the lower layer 3 will be explained. Ag is used for the lower layer 3. This Ag is
Of course, it is a material with very good conductivity.

For the upper layer 2, Ag in which SnO□ and InzO= are dispersed is used.

As the amounts of SnO2, In, and O contained in Ag increase, the hardness increases and the welding resistance improves, but the electrical conductivity deteriorates. Considering that it is used in a relay (power relay) whose contacts have a large current capacity, it is necessary that the conductivity is approximately 40 LAC3% (100 LAC3% is the conductivity of pure copper) or more. Therefore, the thickness and conductivity of both the upper and lower layers 2 and 3 are adjusted so that the conductivity exceeds 40 LAC 3% and the hardness also increases. The thickness of the upper layer 2 depends on the load conditions, but considering the amount of wear caused by opening and closing, the thickness of the upper layer 2 is 10~
Approximately 200 μm is appropriate.

From the viewpoint of welding resistance, it is desirable that the total weight of In and Sn is 10% by weight or more with respect to the total weight of Ag, In, and Sn in In2O and 5nOz in terms of metal elements. If it is less than 10 fIit%, the effect of improving the welding resistance will be poor.

Furthermore, in addition to In, O, and SnO, A1t0
By dispersing 3 in Ag with the addition of MnO as necessary, the conductivity slightly decreases but the hardness increases, which outweighs the decrease in conductivity and improves the welding resistance. be able to. AlzC dispersed in Ag
) + and MnO are calculated by converting all metal oxides in Ag into metal elements, and the total weight of A, l, and Mn is 0.5 to the total amount of Ag and metal elements. It is desirable that it is less than % by weight. For example, the contact material is manufactured as follows. A metal plate made of an alloy containing an oxidizable metal element and a material with good conductivity,
After joining, the sheets are rolled or rolled and joined at the same time to finish the plate material to the desired thickness. Thereafter, oxidation treatment is performed using an internal oxidation method to oxidize the oxidized metal within the alloy and increase the hardness of the alloy portion. In other words, the alloy portion becomes a layer made of a material with high hardness.

Next, more specific examples and comparative examples will be explained.

(Examples 1 to 4 and Comparative Example) Elements such as Ag, Sn, In, At, and Mn were appropriately selected and weighed. It was melted using a high frequency furnace in an argon gas atmosphere and cast into a mold to obtain alloy ingots with different compositions as shown in Table 1. A pure Ag material was joined to these alloy ingots by hot pressure welding to obtain a laminated metal material. Furthermore, it was formed into a plate with a thickness of 1 in a rolling process, and then passed through a punching process to form a fixed contact with a diameter of 5 mm and a movable contact with a shape of 5 mm x 12 mm. These were heat-treated at 700° for 100 hours in an oxygen atmosphere for internal oxidation to obtain five types of contact samples.The thickness of the pure Ag material joined to the alloy ingot was determined by the rolling process. Also, the thickness is selected in advance as shown in Table 1.

A for the three pairs of contact samples on each side obtained as above.
Opening/closing tests were conducted using an STM type contact testing machine, and electrical conductivity was also measured. The test conditions were as follows.

Voltage: AC 100cm Current: rush 118A, steady 20A Contact force: 100g Breaking force 1150g Number of openings and closings 110,000 times According to this test method, the welding resistance was evaluated by the number of times welded. In other words, the smaller the number of times of welding, the better the welding resistance. The results of measuring the number of times of welding of the contact samples are shown in Table 1 by taking the average value of three pairs of each example.

As shown in Table 1, it can be seen that all of Examples 1 to 4 using the contact material of the present invention have improved welding resistance compared to the comparative example. At the same time, the electrical conductivity has improved dramatically.

It goes without saying that the electrical contact material according to the present invention is not limited to the structures and materials exemplified above, but may be any material as long as it provides the same effects. For example, the layer made of a highly conductive material may be made of an Ag-Ni based material.

〔Effect of the invention〕

As described in detail above, the contact material according to the present invention is provided on a layer made of a highly conductive material. It has a structure in which a layer made of a material harder than '4 is provided. Therefore, it has excellent welding resistance while maintaining good conductivity, so even when used for contacts with a large current capacity, the contacts do not easily weld and the contact resistance value is low. can be maintained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of a contact material according to the present invention. 1...Contact material 2...Upper layer (layer made of material with high hardness) 3...Lower layer (layer made of material with good conductivity) Agent Patent attorney Takehiko Matsumoto Figure 1 Hand 3 Sales (Masori Ho) (Sponsored by the Commissioner of the Patent Office on January 1, 1986)
-'1, 1985 Cow's Aaun Patent Application No. 23843'O2, Name of Invention Electrical Contact Material 3, Person Who Corrects iliRelationship with Cow Address of Patent Applicant Kadoma, Osaka Prefecture City Oaza Oma 1048 address name +! F (583) Matsushita Electric Works Co., Ltd., Representative Hitoshi, Representative Tan Tei, Sadao Fujii 4, Substitute - No embedding, Patent Application No. 60-238430 6, Specification subject to amendment - 7, Contents of amendment (1) Specification No. On page 5, line 15, the text ``rLAC3%'' is corrected to ``r [AC3%''. (2) On page 5, line 16 of the specification, the statement "rt, Acs%" is corrected to "r I AC3%". (3) On page 5, line 18 of the specification, the statement "rLAC3%" is corrected to "rlAcs%". (4) In the top row of the second column from the right of Table 1 on page 10 of the specifications, the text "LΔCS%" is corrected to "[ΔCS%."

Claims (9)

[Claims] (1) An electrical contact material in which a layer made of a material with higher hardness than the above material is provided on a layer made of a material with good conductivity. (2) Ag whose highly hard material contains metal oxides
An electrical contact material according to claim 1. (3) SnO_2 and In_2O as metal oxides
The electrical contact material according to claim 2, wherein _3 is dispersed in Ag. (4) The electrical contact material according to claim 3, wherein Al_2O_3 is also dispersed in Ag. (5) The electrical contact material according to claim 4, wherein MnO is further dispersed in Ag. (6) The electrical contact material according to any one of claims 1 to 5, wherein the material with good conductivity is Ag. (7) The thickness of the layer made of a material with high hardness is 10 to 20
The electrical contact material according to any one of claims 1 to 6, which has a diameter of 0 μm. (8) The electrical contact material according to any one of claims 1 to 7, wherein the layer made of a highly conductive material is thicker than the layer made of a hard material. (9) A layer made of a highly hard material is formed by laminating an alloy layer to a layer made of a highly conductive material and converting the oxidizable metal element in this alloy layer into an oxide using an internal oxidation method. An electrical contact material according to any one of claims 1 to 8.