JPH06100965A - Electrical contact material - Google Patents

Abstract

PURPOSE:To improve the mechanical strength and welding resistance of an electrical contact material and to expand the range of the using electric current by mixing and sintering powder obtd. by subjecting Ag alloy powder contg. Cd, Sn, Sb or the like to internal oxidation with Fe powder and dispersing the same components by prescribed amounts into Ag. CONSTITUTION:This electrical contact material is formed by mixing and sintering powder obtd. by subjecting Ag-alloy powder to internal oxidation with Fe powder. Then, by weight, 0.1 to 15% Fe and one more kinds among, by weight, 0.05 to 10% Cd, Sn, Sb, Zn, In, Bi and Te are dispersed into Ag. In this way, its mechanical strength is improved without deteriorating its workability and spot weldability, and its welding resistance is improved to expand the range of the using electric current.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Ag-Fe alloy electric contact material.

[0002]

2. Description of the Related Art Conventionally, various materials have been used as electric contact materials, but especially Ag-Fe contacts are widely used in place of Ag because of their low contact resistance and low consumption. In addition, since Ag-Fe is easy to process and spot weld, it is possible to automate the work of sticking to a base material, etc., resulting in low assembly costs and stable quality.

[0003]

[Problems to be Solved by the Invention] However, Ag-Fe
Has a problem that its mechanical strength is small and its welding resistance is inferior to that of Ag-oxide systems such as Ag-CdO, so that its use range is limited to a relatively small current region. In recent years, various devices and equipment have been aiming for weight reduction, downsizing, and large capacity, but also from this point, there is a problem that the Ag-Fe-based welding resistance is poor.

As a method for solving these problems, Ag-
We are trying to improve the characteristics by adding various metallic elements to the Fe alloy. Ag-Fe alloys are manufactured by powder sintering because there is almost no solid solubility between Ag and Fe, but the above-mentioned attempts have not yet reduced the effect of arc heat generated during opening and closing. The stable contact characteristics, which are the original characteristics of the Fe alloy, are impaired, and the welding resistance is reduced due to temperature rises.

Further, the workability and spot weldability, which are the characteristics of Ag-Fe alloys, are hindered by the mixture of various additives.
There is also a problem that the automation line cannot be assembled. Therefore, an experiment was conducted based on the idea that the various phenomena of oxides against arc, such as the contact surface cleaning action and the arc extinguishing action, are most closely related to the properties of the added oxide, especially the vapor pressure temperature characteristics. As a result of repeating, Cd, Sn, Sb, Zn, In, Bi, Te
By adding at least one kind of each oxide of
It has been found that there is a great effect in improving the mechanical strength and the welding resistance without deteriorating the workability and spot weldability, which are the characteristics of Ag-Fe, and expanding the operating current range.

[0006]

[Means for Solving the Problems] Therefore, according to the present invention, Fe is 0.
Mix 1 to 15Wt% Fe powder and Ag-alloy powder containing 0.05 to 10Wt% of Cd, Sn, Sb, Zn, In, Bi and Te in Ag. It is characterized by being sintered.
According to the present invention, 0.1 to 15 Wt% Fe and Cd, Sn, Sb, Z in Ag are used.
By dispersing at least one of n, In, Bi, and Te in the range of 0.05 to 10 Wt%, the effect of arc heat generated during switching is reduced.

Here, the addition amount of Fe to Ag is 0.1 to 15 Wt%
The reason for limiting the content to 15 Wt% is that the addition of more than 15 Wt% not only deteriorates the original contact resistance characteristics of Ag-Fe but also impairs the workability. If it is added less than that, the wear resistance is impaired, and the effect is minimal. And, the reason for setting the upper limit of addition of at least one of Cd, Sn, Sb, Zn, In, Bi, and Te to 10 Wt% is that when the addition amount exceeds that, it becomes very brittle and Ag- This is because the good workability, which is the original feature of Fe, is reduced and the welding resistance is impaired due to temperature rise. In addition, the lower limit of 0.05 Wt% is the minimum effect.

[0008]

EXAMPLES Examples of the present invention will be described below.

[0009]

[Table 1]

[0010]

[Table 2]

Tables 1 and 2 show examples of the present invention, wherein an alloy containing at least one of Cd, Sn, Sb, Zn, In, Bi and Te in Ag was made into powder by an atomizing apparatus. Internal oxidation,
Fe powder of 300 mesh or less was mixed using a V-type mixer, and blended so as to have the respective compositions as in Examples 1 to 20 in Table 1 and Table 2. These are 60φ × 150m at a pressure of 2.5t / cm ^2.
The molded material was molded into m 2, and the molded material was heated and sintered in an inert atmosphere at a predetermined temperature for a predetermined time to form a billet, which was further heated in an inert atmosphere and extruded into a wire having a diameter of 10φ.

Annealing and drawing were repeated in an inert atmosphere to obtain a wire material having a diameter of 6φ, and header processing was performed to obtain a rivet-shaped contact material having a diameter of 6φ. The contact resistance, the amount of wear, and the number of weldings of the rivet-shaped contact material produced as described above were measured under the following conditions using an ASTM tester.
The results are shown in Tables 3 and 4.

[0013]

[Table 3]

[0014]

[Table 4]

In each of Examples 1 to 20, the Ag layer formed on the back side of the alloy and the pedestal for holding the contact were used as a sample for the contact test by silver brazing to prepare a sample, and an ASTM tester (AC100V, 20A), arc wear tester (AC200V, 20A), select the test conditions for each item listed in Table 3 and 4 while comparing with the typical electrical contact materials that have been widely used in the past. Each contact material was tested under the same conditions.

[0016]

According to the present invention described in detail above, Fe
Powder and at least one of Cd, Sn, Sb, Zn, In, Bi, Te in Ag
By mixing and sintering Ag-alloy powder containing more than one kind of powder with internally oxidized powder, the mechanical strength and welding resistance can be improved without degrading the workability and spot weldability, which are the features of Ag-Fe. It is possible to improve and expand the range of current used.

Claims (1)

[Claims] 1. Fe powder containing 0.1 to 15 Wt% Fe and Cd, S in Ag.
At least one of n, Sb, Zn, In, Bi, Te is 0.05 to 10
An electrical contact material characterized by mixing and sintering Ag-alloy powder containing Wt% and a powder obtained by internal oxidation.