JPH0130899B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to electrical contact materials. Conventionally, silver cadmium oxide has been mainly used as an electrical contact material manufactured by an internal oxidation method. Silver cadmium oxide has anti-wear properties,
It has excellent contact performance such as anti-welding properties and low contact resistance properties, but recently there has been an active effort to develop contact materials with superior performance. A variety of electrical contact materials have emerged from these trends, including silver-tin, silver-indium, silver-bismuth, and silver-zinc materials. Although it has extremely excellent performance in terms of wear resistance, welding resistance, low contact resistance, etc., it is not as good as silver cadmium oxide when overall contact characteristics are taken into consideration. Therefore, the present inventors conducted extensive research to develop an electrical contact material with overall superior contact characteristics than these electrical contact materials, and as a result, they developed a satisfactory electrical contact material made of a silver-bismuth oxide-antimony oxide alloy. This is what I discovered. One of the electrical contact materials of the present invention is an electrical contact material made of a silver-bismuth oxide-antimony oxide based alloy, which has a weight ratio of bismuth 4 to 4 before internal oxidation.
10% by weight, 1-5% by weight of antimony and the balance silver. Another electrical contact material of the present invention has a total weight ratio of at least one of lanthanum boride and titanium carbide of 0.001 to 3% by weight, bismuth 4 to 10% by weight, and antimony 1 to 1% by weight before internal oxidation. It is characterized by consisting of 5% by weight and the balance being silver. In the electrical contact material of the present invention, bismuth is added to 4
The reason why bismuth is set at ~10% by weight is because although less than 4% by weight bismuth can provide good contact resistance properties, good results in terms of welding resistance cannot be obtained.
This is because if it exceeds 10% by weight, a thick oxidized band will be formed on the surface of the silver-based alloy, increasing the contact resistance. The reason why antimony is set at 1 to 5% by weight is that if it is less than 1% by weight, the effect against bismuth oxide is weak and good results cannot be obtained in terms of welding resistance and wear resistance, and if it exceeds 5% by weight, workability is poor. This is because it becomes difficult and the contact resistance also increases. Furthermore, the reason for containing 0.001 to 3% by weight of at least one of lanthanum boride and titanium carbide in addition to 4 to 10% by weight of bismuth and 1 to 5% by weight of antimony is that silver-bismuth oxide-antimony oxide This is because when dispersed in an electrical contact material made of a series alloy, arc discharge is dispersed on the surface of the electrical contact, the discharge is no longer concentrated in one place, and wear due to discharge is reduced. This is because discharge is not dispersed and if the content exceeds 3% by weight, the amount of discharge increases and the amount of consumption increases. Next, in order to clarify the effects of the electrical contact material according to the present invention, specific examples and conventional examples will be described. The materials having the compositions of Examples 1 to 7 and Comparative Examples 1 to 4 shown in the left column of the table below were dissolved to form atomized powder, and then internally oxidized at 400 ° C. and 4 atmospheres for 2 days.
This oxidized atomized powder is compressed and sintered, extruded and drawn, then cut and headered to obtain a rivet-type electrical contact with a head diameter of 4 mm, a head of 1.1 mm, a leg diameter of 2.8 mm, and a leg length of 1.6 mm. Ta. In addition, among the materials having the compositions of Examples 8 to 13 shown in the left column of the table below, silver, bismuth, and antimony were dissolved and atomized powder was prepared at 400°C and 4 atm.
After internal oxidation for 2 days, this oxidized atomized powder was mixed with the remaining powders of TiC and LaB ₆ , each having an average size of 1μ, in a V-shaped mixer for 3 hours, then compressed and sintered, and then extruded and drawn. After cutting and header processing, head diameter 4φmm, head 1.1mm, leg diameter 2.8φ
A rivet-type electrical contact with a leg length of 1.6 mm was obtained. However, the rivet type electrical contacts made from the electrical contact materials of Examples 1 to 13 and Comparative Examples 1 to 4,
Rivet-type electrical contacts of the same dimensions made using materials having the compositions of Conventional Examples 1 and 2 shown in the left column of the table below in the same manner as in the examples were subjected to opening/closing tests under the test conditions below. The results shown in the right column of the table were obtained. Test conditions Voltage: AC100V 50Hz Current: 40A, steady 10A Load: Resistance Switching frequency: 20 times/min Number of switching: Until welding

【table】

[Table] As is clear from the above table, the rivet-type electrical contacts made with the electrical contact materials of Examples 1 to 13 are the same as the rivet-type electrical contacts made with the electrical contact materials of Conventional Examples 1 and 2 and Comparative Examples 1 to 4. It can be seen that the welding resistance and wear resistance are far superior to that of contacts, and the contact resistance is almost equally low. As detailed above, the electrical contact material of the present invention has contact properties that are comprehensively superior to conventional electrical contact materials, so it can be said that it is an epoch-making product that can replace conventional electrical contact materials. .

Claims (1)

[Claims] 1. An electrical contact material made of a silver-bismuth oxide-antimony oxide based alloy, which has a weight ratio of 4 to 10% by weight of bismuth, 1 to 5% by weight of antimony, and the balance before internal oxidation. An electrical contact material characterized by: 2 The total weight ratio of at least one of lanthanum boride and titanium carbide before internal oxidation is 0.001 to 3.
wt%, bismuth 4-10 wt%, antimony 1-1
An electrical contact material comprising 5% by weight and the balance being silver.