JPS5884941A - Electrical contact material - Google Patents

Abstract

PURPOSE:To improve the rapid arc disappearance, hardly dissipative property and welding resistance of the resulting titled material and to reduce the contact resistance by dispersing the carbide of a IVa, Va or VIa group metal, graphite and the nitride of a IVa, Va, VIa, VIIa or VIIIa group metal in silver. CONSTITUTION:This electrical contact material has a composition consisting of, by weight, 5-70% carbide of a IVa, Va or VIa group metal, 1-11% graphite, 0.1-30% nitride of a IVa, Va, VIa, VIIa or VIIIa group metal, and the balance silver. Said carbide, nitride and graphite are dispersed in the silver.

Description

[Detailed description of the invention] It relates to gas contact materials.

In particular, the purpose is to improve the properties of Ag-W and Ag-We alloys.

Ag-W has conventionally been widely used as contacts in air circuit breakers, switches, etc. due to its excellent arc resistance, wear resistance, and welding resistance. However, there is a drawback that W oxidizes during use, resulting in increased contact resistance. Therefore, in order to meet this demand, an Ag-We contact was developed in which "fia" was added to Ag instead of W.
The purpose of using B wC is to prevent W from oxidizing during use and prevent contact resistance from increasing. However, the poor wettability of Ag and W (7) and the
The addition of . For this reason, there is a demand for the development of contacts with even better arc breakage and excellent wear characteristics.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a highly practical contact alloy that has arc breakability, wear resistance, and welding resistance, and has low contact resistance. .

The alloy according to the present invention is an electrical contact material characterized by containing dispersed in silver a carbide of a group metal TVa% Va% VIa% a1 a nitride of a group metal and graphite. be.

The present inventors have discovered that when nitrides of group metals such as Na, VL, and carbides of group a metals are added to carbides of group metals such as It was discovered that carbides and nitrides react, making the carbides finer and less deformed at high temperatures. Furthermore, it has been found that the addition of these nitrides significantly improves arc wear resistance. These characteristics are due to the fact that carbides and nitrides are decomposed by the arc heat generated during opening and closing, and the generated C gas reacts with the nitrides. This reaction is an endothermic reaction, and N gas, which has an arc-extinguishing effect, is released. It is thought that the arc resistance characteristics will be improved.

However, carbides and nitrides have poor oxidation resistance and are oxidized by the arc heat generated during switching, increasing contact resistance and increasing the temperature of the equipment.Gr is decomposed by the heat during electrical switching. It was found that Gr generates reducing gas, prevents nitrides and carbides from oxidizing, keeps contact resistance low, reduces temperature rise in equipment, and improves welding resistance due to the lubricity of Gr. This allows conventional Ag
-W series, Ag -We series, and Ag -We -Gr series contacts (we were able to obtain alloys that had unexpectedly high performance welding resistance, abrasion resistance, and temperature rise characteristics).

Carbides include WXMOTa, Nb5Ti, Or
Carbides of Na1, a1, and a group metals are effective, and the amount thereof is preferably 3 to 70% by weight.
! ;0% by weight has good properties. The carbides did not decrease by 5% by weight, and no improvement in temperature rise characteristics was observed.1°Nitrides include T1, Zr, Nb, Cr, and MoXMn.

Nitride of IVa%Va%VI&%■a1■a group metal such as 're' is effective, and the amount of the metal is preferably 0.7 to 30% by weight, especially o, s-, :zo weight%. Good characteristics I/).

If it is less than 0.1% by weight, the effect of wear resistance is small, and 30
This is because if Gr is added in excess of 1% by weight, the contact resistance will increase and the temperature increase characteristics will decrease.The effective range of zero order Gr is 1 to 1% by weight, preferably 3 to 7% by weight. %. If the content of iron group metals and carbides is less than 1% by weight, no improvement in temperature rise characteristics will be observed even if the content of iron group metals and carbides is within the above range.
If it exceeds % by weight, alloy production is difficult and impractical.

It should be noted that θ, approximately 1% by weight of Al5, does not impair the purpose of the present invention.
Si, Ss, Te, Bi, Zn, Cd, In, S
n.

There is no problem even if metal elements such as Oa and Na are included.

Next, the characteristics of the contact alloy according to the present invention will be specifically explained using examples.

Examples Table 1 - Each powder was blended in the proportions shown in Tables 2, 3 and 9, and after mixing, a molded body was made and the molded body was sintered at a temperature of /10θC in a hydrogen atmosphere. did.

It is a conventional alloy.

Table l Unit: Weight %
Table Unit 2 Weight Test Table 3 Unit: Weight % Opening/closing frequency 7200 times/hour, number of opening/closing 200,000 times, contact dimensions lo x to x j w The results of contact resistance and wear amount are shown in the figure.

As shown in the figure, it can be seen that the alloy of the present invention has low wear, low contact resistance, and high performance contact characteristics.

As mentioned above, the alloy of the present invention has excellent contact performance and is therefore of high industrial value.

[Brief explanation of drawings]

The figure shows the relationship between the N closure number, contact resistance, and amount of wear of the alloy of the example.

Claims (1)

[Scope of Claims] (1) Carbides of metals from Groups ■a, VL, and ■A of the Periodic Table of Elements are S to 0% by weight, graphite lNl/
An electrical contact material characterized in that the nitride of a group metal is θ, l to 30% by weight, the balance being silver. (c) Carbide is tungsten, molybdenum, tantalum,
The electrical contact material according to claim (1), characterized in that it is a carbide of at least seven types of niobium, titanium, and chromium. (3) The electricity according to claim (1), wherein the nitride is at least one nitride of titanium, zirconium, 1-niobium, chromium, molybdenum, manganese, iron, vanadium, and tantalum. Contact material.