JPH03184219A - Manufacture of electric contact material - Google Patents

Abstract

PURPOSE:To manufacture an electric contact material which has strong spring property and is hard to buckle by underplating a specified base material with Ni in a specified thickness, drawing the base material after it is plated with Au in a specified thickness, and heat-treating it. CONSTITUTION:A base material 1 consists of 30-40wt.% of Co, 10-20wt.% of Ni, 10-20wt.% of Cr, 2-10wt.% of W, 2-10wt.% of Mo, <=1wt.% of Ti, <=1wt.% of Mn, <=1wt.% of Si, and the rest Fe. A Ni film 2 with 0-10mum of plating thickness is formed on the base material 1 as an undercoating, and after a Au film 3 with 0-10mum of plating thickness is formed by plating Au, the base material is drawn and heated at 400-800 deg.C. In this way, mechanical strength, for example, tensile strength and transverse rupture coefficient of the obtained base material become as high as 180-220kg/mm<2> and 7800-8300kg/mm<2>, respectively and thus an electric contact material having strong spring property and being hard to buckle can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a torsion spring used as a switch, and an inexpensive material with good spring properties that can be used as a material for a sliding terminal.
This invention relates to materials for electrical contacts and methods of manufacturing the same.

[Conventional technology]

Conventionally, materials for electrical contacts include Au alloy, Ag alloy,
A noble metal material such as a PT alloy was used, and the properties shown in Table 1 were obtained.

Table 1 shows the mechanical strength of conventional electrical contact materials.

Table 1 [Problems to be Solved by the Invention] However, the conventional materials for electrical contacts as described above are expensive, and when used as contacts, the wire itself has weak springiness and tends to buckle easily. There are challenges.

An object of the present invention is to provide a material for an electrical contact and a method for manufacturing the same, which solves the above-mentioned problems.

[Means to solve the problem]

In order to achieve the above purpose, Co:3 is used as the base material.
0-40% by weight Ni: 10-20% by weight, Cr: 10
~20% by weight, W: 2-10% by weight, Mo: 2-1
0% by weight, Ti 11% by weight or less.

Mn: 1% by weight or less, Si: 1% by weight or less A base material of which the balance is Fe is plated with Ni as a base to a thickness of 0 to 10 μm, and then Au is plated to a thickness of 1 to 10 μm, followed by drawing. By heat treatment at ~800°C, an inexpensive material for electrical contacts with good spring properties is obtained and provided.

[Effect]

By performing a drawing process after applying Au plating to the base material, it is possible to provide an electrical contact material that requires less plating time and is inexpensive.

The mechanical strength of the base material is tensile strength of 180 to 220 kg/
Since it has an openness of 2 and a transverse coefficient of 7,800 to 8,300 kg/mm2, it is possible to provide an electrical contact material that has strong spring properties and is resistant to fading.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings as a preferred example, in which a fine spring wire for a sliding contact of a high-precision potentiometer is obtained. Figure 1 is a cross-sectional view of the plated wire;
FIG. 2 is a sectional view of the die part during drawing, and FIG. 3 is a sectional view of the wire after drawing.

A Co-based alloy having the composition shown below is used as the base material. Co: 30-40% by weight, Ni: 10-20% by weight,
Cr: 10-20% by weight, W: 2-10% by weight, Mo
: 2-I 0% by weight, Ti 11% by weight or less, Mn: 1
5il 1% by weight or less, the balance being Fe.

The wire shown above is subjected to solution treatment at 800° C. to 1200° C., and skin bath drawing processing is performed to correct the curl of the wire. The wire diameter of this base material is 100 to 300 μm.

Thereafter, Ni is used as a base plate and plated to a thickness of 0 to 10 μm, and then Au is plated to a thickness of 1 to 10 μm.

Figure 1 is a cross-sectional view of a plated wire, and 1 is a C
O-based alloy 2 is a Ni film, and 3 is an Au film.

The drawing process that thins this wire to about 65 μm is
A processing rate of 50 to 99% is achieved with an area reduction rate of 3 to 15%. The wire unwound from the supply bobbin is drawn using about 10 to 30 drawing dies, and then wound onto a take-up bobbin. FIG. 2 is a longitudinal cross-sectional view of the die part during drawing processing, and as shown in the figure, the die 4 is entirely covered with lubricating oil 5, and the wire is pulled through the lubricating oil in the direction of arrow a. It is pulled out and becomes a thin line. Figure 3 is a cross-sectional view of the wire after drawing, resulting in several tens of μm in several steps.
It becomes a thin line.

The Au-glad Co-based alloy wire processed in this way is
When heat treated at 400-800℃, the tensile strength increases to 18
0~220kg/m+*2 Transverse coefficient 7800~830
It has a mechanical strength of 0 kg/mm2.

〔Effect of the invention〕

The present invention has the following advantages.

(a) By performing drawing processing after Au plating, the weight of the Au film is extremely small compared to the weight of the Co-based alloy wire, thereby providing a material for electrical contacts that is inexpensive. I can do it.

(a) The mechanical strength of the base material is tensile strength of 180 to 22
0 kg/+1111', elongation 1-3%, Vickers hardness 400-500. Transverse elastic modulus 7700-8300
kg/2, it is possible to provide a material for electrical contacts that has strong spring properties and is resistant to fading.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the plated wire, FIG. 2 is a sectional view of the die part during drawing, and FIG. 3 is a sectional view of the wire after drawing.・Co-based alloy ・Ni film ・Au film ・Drawing die ・Liquid lubricating oil

Claims (1)

[Claims] In the Au-clad Co-based alloy wire having contact properties and spring properties and its manufacturing method, Co: 30 to 40% by weight, Ni
: 10-20% by weight, Cr: 10-20% by weight, W: 2
~10% by weight, Mo: 2-10% by weight, Ti: 1% by weight
Hereinafter, on a base material consisting of Mn: 1% by weight or less, Si: 1% by weight or less and the balance being Fe, 0 to 10 μm thick
A method for manufacturing an electrical contact material, which comprises plating, plating Au to a thickness of 1 to 10 μm, and then drawing it and heat treating it at 400 to 800°C.