JPS5820085B2 - composite electrical contacts - Google Patents

Description

[Detailed Description of the Invention] Composite electrical contacts conventionally manufactured by cold pressure welding consist of a wire piece made of a precious metal material such as gold, silver, gold alloy, or silver alloy forming the contact part and copper forming the base part. Alternatively, wire rods made of base metal materials such as copper alloys are kept clean and stacked and crimped to form one another, but apart from rivet-shaped composite electrical contacts that are caulked to the alloy, they are used by spot welding to the alloy. In the case of a disk-shaped composite electrical contact, it is necessary that the base material forming the base portion thereof be a material suitable for spot welding.

Traditionally, materials suitable for spot welding include iron, nickel, nickel silver, and phosphor bronze, and these materials can be bonded to precious metals as contact materials by methods such as brazing to form composite electrical contacts. It was used by spot welding to the base metal.

However, if you try to form a disk contact by cold welding iron, nickel, nickel silver, phosphor bronze, etc., which have high spot weldability, to gold, silver, or noble metal materials such as gold alloys and silver alloys, the hardness will increase. The mechanical properties such as ratio are inappropriate for crimping to noble metal materials, and perfect crimping cannot be expected.

The present invention improves on this point and relates to a composite electric contact for spot welding that uses a base material that has excellent cold weldability to noble metal materials and high spot weldability.

To explain the present invention in detail, first, it is well known that generally speaking, spot weldability is related to the electrical resistivity R (specific resistance) of the material itself, and the larger R is, the better the spot weldability is. It is a place where you can be

On the other hand, copper is the best base metal material that has cold bondability to noble metal materials, which are relatively soft materials.
In some cases, copper alloys have been used in which cadmium, zircon, or the like is added to 1φ or less.

However, these copper or copper alloys have the above-mentioned electrical resistivity R.
is extremely low, making it unsuitable for spot welding.

Under these circumstances, the present invention focused on a copper-nickel alloy as a base material, and the relationship between the hardness, electrical resistivity, and nickel content of this alloy is shown in Figure 1 (Metal Handbook, edited by the Japan Institute of Metals).・Excerpt from P2S5).

In this case, the hardness is related to the quality of cold pressability to noble metal materials, and the Brinell hardness of various materials is shown in Table 1 at the end of this section (detailed description of the invention).

Now, if we first focus on the cold crimp properties of composite electrical contacts,
As shown in Table 1, the hardness of the precious metal material is HB30-40.
In contrast, iron, nickel, and
Nickel silver, phosphor bronze, etc. have a hardness of H860 or higher, which is too high, and in the crimping process of composite electrical contacts, slipping occurs between the noble metal material and the base material, making crimping impossible.

On the other hand, copper, copper cadmium, or copper zircon can suppress slippage between the noble metal material and the base material during compression molding when the HB is 50 or less, so that good compression bonding can be obtained.

From this point of view, when looking at copper-nickel alloys, as shown in Figure 1, the hardness H is suitable for cold crimping with noble metal materials.
The Ni content of B50 or lower is 15 tres or less, and the electrical resistance in this case is about 18 μΩ/d, which is about 100 times that of copper, which is about 0.2 μΩ/d, and the spot weldability is extremely good4.
Become.

If the Ni content is gradually decreased from 15%, the cold pressability will further improve, but the electrical resistance will decrease, so the spot weldability will become lower.

If the content is less than NiS, spot weldability deteriorates and spot welding becomes difficult in practice.

Therefore, for compression molding on precious metal materials, 5 to 1 nickel is added to copper.
Copper-nickel alloys containing 5% are most suitable.

In this way, as shown in FIG. 2, a wire rod piece 1 made of a precious metal material such as gold, silver, gold alloy, silver alloy, etc., which forms a contact portion, is formed.
Then, the wire rod pieces 2 made of a copper-nickel alloy base metal material containing 5 to 15 nickel in the copper forming the base part are stacked and pressed with a receiving die 3, a header 4, and a receiving pin 5 while keeping each wire clean. Pressure molding is performed to obtain a disk-shaped composite electrical contact 6 as shown in FIG.

The composite electrical contact 6 has a noble metal material part 1' and a copper base part.
It will be formed of a nickel (5-15%) alloy 21.

The disk-shaped composite electric contact constructed in this manner is extremely advantageous because cold crimping can be carried out automatically and thus contacts for spot welding can be provided at low cost.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between the hardness and electrical resistance of the copper-nickel (5-15%) alloy used as the base material of the composite electrical contact according to the present invention, and the nickel content, and Figure 2 is a diagram showing the relationship between the nickel content and the hardness of the copper-nickel (5 to 15%) alloy used as the base material of the composite electrical contact according to the present invention. FIG. 3 is an explanatory diagram of the pressure-bonding process of the composite electrical contact of the present invention. FIG. 3 is an explanatory diagram of the composite electrical contact of the present invention.

Claims (1)

[Claims] 1 A disk-shaped composite electric contact consisting of a contact part made of a noble metal material such as gold, silver, gold alloy, silver alloy, etc., and a base part cold-pressed to the contact part, and the base part is made of nickel 5
It is made of a single member of a copper-nickel alloy containing ~15%, and is characterized by being cold crimped to the contact portion with excellent cold crimping properties and having high spot weldability to alloy metals. Composite electrical contacts as described above.