JPS6010410B2 - Composite plated contacts - Google Patents

Description

[Detailed description of the invention] This invention relates to composite plated contacts.

/ Silver-based materials, platinum-based materials, and alloys mainly composed of gold have been used as switching contact materials for light current applications.

However, contacts using silver-based materials formed an insulating film in the atmosphere, lacked corrosion resistance, and had poor contact characteristics. Contacts made of platinum group materials have a problem in that insulating organic matter (brown powder) is generated on the contact surface when switching at light loads (for example, 0.1 V, lmA), resulting in poor contact.

It does not have contacts made of gold or gold-based alloys and has excellent corrosion resistance and contact characteristics, but has a problem of lacking wear resistance due to its low melting point and softness. Accordingly, an object of the present invention is to provide a composite plated contact for use in the air for use in the atmosphere, which has good corrosion resistance and contact characteristics, and is highly wear resistant.

In summary, the plated contact of the present invention has WC particles dispersed in a platinum group element or an alloy containing a platinum group element as a main component.

In this way, since a platinum group element or an alloy containing platinum group elements as a main component is used as a material, there is no formation of an insulating film in the atmosphere, which is a disadvantage of conventional contacts using silver-based materials, and it has excellent corrosion resistance. become something. In addition, the generation of brown powder in the atmosphere, which is a disadvantage of contacts made of platinum group elements, is suppressed, and corrosion resistance and contact characteristics are improved.
Abrasion resistance is also improved. Next, this invention will be explained in detail. WC particles dispersed in platinum group elements or alloys mainly composed of platinum group elements have high hardness, high melting point, corrosion resistance,
It has oxidation resistance and conductivity properties.

In addition, free carbon in the WC particles further extends the life of the contacts. That is, since carbon is a substance that tends to cause electrical discharge, the carbon in the area where the electrical discharge occurred will burn, and the next electrical discharge will occur in another area. Therefore, the discharge is dispersed and the contact surface is worn out smoothly. Furthermore, WC particles are relatively easy to obtain, can be mass-produced, and are inexpensive. A contact layer using these WC particles is shown in FIGS. 1 and 2.

In these figures, 1 is a platinum group element or an alloy mainly composed of a platinum group element, and 2 is WC particles dispersed therein. In this case, the thickness of the contact layer is preferably 1 to 15 m. Further, the diameter of the WC particles 2 is preferably 10 m or less, and the amount thereof is preferably 20 to 8% by vessel volume. In this way, W, which has higher hardness and superior properties, is added to platinum group elements or alloy 1 whose main component is platinum group elements.
Since the C particles 2 are dispersed, a contact using the C particles has improved anti-seizure properties and wear resistance, and stable contact characteristics. In particular, as shown in Figure 2, if WC particles 2 are densely dispersed on the contact layer surface to form a film of WC particles 2 to prevent exposure of platinum group elements or alloy 1 whose main component is platinum group elements, brown powder The occurrence of this will be further reduced. Therefore, when used under light loads (for example, 0.1 V, lmA), contact failures will not occur. Of course, this contact structure can be used with a relatively large capacity load (for example, 20V, IA). In addition, it is preferable to use the plating method to disperse the WC particles uniformly in the contact layer or densely on the surface as shown in Figure 2. It has poor dispersibility and cannot obtain a stable quality of berries. The composite plated contacts obtained in this way prevent the generation of brown powder and have excellent corrosion resistance, so they can be used at light loads (0.1V, lmA) in switching contacts designed with relatively low contact pressure. It has an excellent effect on improving contact reliability when opening and closing.

Moreover, there is no welding even under relatively large loads (for example, 20 V, IA), and contact reliability is high. That is, by using this composite plated contact, a switching contact that can be opened and closed over a wide range can be obtained. Furthermore, since WC particles with high hardness are dispersed, wear resistance is also improved. Next, preferred embodiments will be described.

Example 1: WC particles were mixed into a Pd-Nj alloy plating layer, and Pd
A contact layer was formed by eutectoidizing WC particles together with the -Ni alloy by a plating method, and a composite plated contact was obtained.

In this case, the composition of the Pb-Ni alloy plating case was set to be Pd8 weight % and Ni 2 weight %. WC particles have a particle diameter of l
It was rm. Then, the eutectoid amount of WC particles was set to %. The composite plating method and conditions in this case are as follows. '1' Plating liquid (palladium-nickel alloy plating liquid PNP80 manufactured by Nisshinsha Co., Ltd.) '2) Amount of composite particles mixed: 25 minutes/day ■ Liquid temperature:
30qo'41 Current density:
IA/d〆{5} Fly method:
In this case, the amount of eutectoid can be controlled by adjusting the current density, and by controlling this, the composite particles were co-deposited in a dense state on the surface of the contact layer.

Comparative Example 1: Mixing of composite particles was stopped, and a Pd-Nj alloy plating bath consisting of only 80% by weight of Pd and 20% by weight of Ni was used.

Otherwise, a contact layer was formed and a contact was obtained in the same manner as in Example 1. Comparative Example 2: Contacts were made of gold.

The results of the open life test of the bush points obtained in Example 1 and Comparative Examples 1 and 2 are shown in the following table.

Table 1 In addition, in the 20V, IN Tatsumi closed test, the lifespan was determined as follows:
When the contact resistance reached 40, the life was reached.

In addition, in the 0-IV, lmA opening/closing test to examine the presence or absence of contact failure due to the generation of flounce powder, the end of life was defined as the point at which an initial error occurred. Example 2: Same Pd-Ni as above
Composite contact A was obtained by mixing WC particles into an alloy plating solution (PNP80) and eutectoiding the WC particles together with the Pd-Ni alloy on the substrate by a plating method.

On the other hand, composite contact B was obtained using the same machine as above except that TIC particles were used instead of WC particles.

Using a contact composited with these WC particles and TIC particles, the switching life of the contact at 20V and IA (p9
5) and the initial contact resistance was investigated. The results are shown in the table below. Table 2 From the results, it can be seen that contact A containing WC particles has a longer switching life and lower initial resistance than contact B containing TIC particles.

[Brief explanation of drawings]

FIGS. 1 and 2 are diagrams showing the structure of a contact layer comprising a composite plated contact of the present invention, respectively. 1...Platinum group element or alloy mainly composed of platinum group element,
2...WC particles. Figure 1 Figure 2

Claims (1)

[Claims] 1. A composite plated contact for aerial switching in which WC particles are dispersed in a platinum group element or an alloy containing platinum group elements as a main component.