JPH02423B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] This invention belongs to the technical field of silver-nickel electrical contact materials. [Background technology] Conventionally, electrical contact materials contain tin oxide,
Those containing various metal oxides such as cadmium oxide, zinc oxide, or indium oxide, and those containing other simple metals such as nickel in a silver base are known. Contact materials having the former composition are manufactured by preparing a predetermined silver alloy in advance and subjecting it to internal oxidation to form a predetermined metal oxide in the silver matrix. In addition, in the latter method, a small amount of an elemental metal was mixed with silver, and through a sintering process, the elemental metal was incorporated into the silver base to obtain a contact material classified as a so-called sintered contact material. The former is excellent in wear resistance, welding resistance, etc. required for contacts, but has the disadvantage that the contact resistance at the contact surface becomes large because oxides with low electrical conductivity are dispersed in the structure. Furthermore, since the silver is melted by the arc that occurs when the contacts are opened and closed, oxides are agglomerated and unevenly distributed, resulting in unstable contact resistance. Furthermore, after internal oxidation, the processability into contacts with the specific shape required for the contact material deteriorates, so in the internal oxidation process, an alloy with the desired contact shape is manufactured in advance, and However, it is necessary to carry out internal oxidation, and the mass productivity required in industry is lacking. On the other hand, silver-nickel contacts that belong to the latter category have low contact resistance in the closed state, excellent wear resistance, and are easy to plastically deform, making it easy to form contacts into a desired shape. It has excellent workability, and is excellent in, for example, making wire rods by hot extrusion, molding with headers, and pressure welding with copper base metals. However, for example 2A/
For currents of mm ² or more, welding occurs between contacts, which limits the range of use due to welding resistance. [Purpose of the Invention] This invention solves a problem that silver-nickel based contact materials have, namely that an arc is generated when the contacts are opened and closed, and the energy of the generated arc between the contacts melts the silver and nickel on the contact surface. This was done with the aim of solving the problem of avoiding welding caused by. [Disclosure of the invention] This invention consists of silver, nickel, and zirconium, in which the amount of nickel is more than 10% by weight and less than 20% by weight, and the amount of zirconium is 0.05 to 8% by weight.
The object of the present invention is to provide an electrical contact material characterized in that it contains % by weight. This invention will be explained in detail below. To explain the raw material system of silver, nickel, and zirconium, these raw materials are mixed in powder form so that the three components are uniform. Since nickel and zirconium are in small quantities compared to silver, they must be sufficiently mixed so that they are not unevenly distributed. The mixed powder is placed in a mold and molded into the desired shape. The shaped material is sintered in an inert or reducing gas. Sintering is performed until the density reaches a property of approximately 1. It is effective to repeatedly perform molding and sintering to increase density, and density is an important physical property in that it affects the various performances required of contacts. The following will explain based on examples. [Example] Contact materials having the compositions shown in Table 1 were prepared as Examples 1 to 7 and a comparative example, and various performances were confirmed. Table 1 confirms the structure of the present invention. If the proportion of zirconium is fixed at 1% by weight, for example, and nickel is increased in the range of 10 to 25% by weight (excluding 10% by weight), the amount of consumption increases. Although the contact resistance tends to increase slightly, no significant performance improvement is observed. However, although these performances are not improved, in the system with zirconium added,
The welding resistance is significantly improved and the practicality is increased. The effect of adding nickel is preferably 10 to 20% by weight (however, 10% by weight is not included). If the nickel content is less than 10% by weight, welding will be poor, and if it exceeds 20% by weight, the wear performance will be poor.
Examples 1 and 2 support these facts,
This shows a particularly practical composition. Furthermore, when the proportion of nickel is fixed at 11% by weight, for example, and as zirconium is increased in the range of 0.05 to 8% by weight, the amount of wear and contact resistance tend to increase, indicating that the damage caused by the addition of zirconium is On the other hand, there is a slight improvement in welding resistance. In other words, if the zirconium content is less than 0.05% by weight, there is no increase in wear amount or contact resistance, but no welding resistance effect is observed, and there is no effect. If the addition of zirconium exceeds 8% by weight, the amount of wear and contact resistance will significantly increase compared to when no zirconium is added, and the welding resistance will not be improved, making it ineffective. The addition of zirconium is from 0.05% to 8% by weight considering the balance of these contact properties.
A range of is preferred. Examples 3 to 5 confirm these facts, and particularly show compositions within a range of excellent practicality. Note that performance tests regarding wear resistance and welding resistance were conducted in accordance with ASTM tests. Conditions are: AC: 100V, 40A Contact force: 200g Breaking force: 340g Contact shape used in the test: Combination of 12R (5φ x 1) spherical body and 5φ x 1 flat plate Wear resistance: Opening and closing times 5 The weight loss after 10,000 cycles was calculated as the amount of wear, and the welding resistance was evaluated by the number of welding cycles after 50,000 cycles.

【table】

[Table] [Effect of the invention] This invention consists of silver, nickel, and zirconium, and the nickel content exceeds 10% by weight, and
The content of zirconium is within the range of 20% by weight or less, and the content of zirconium is 0.05 to 8% by weight, with the remainder being silver, which has the effect of improving the welding resistance.

Claims (1)

[Claims] 1 Consisting of silver, nickel, and zirconium, with a nickel content of more than 10% by weight and 20% by weight
The zirconium content is within the following range.
An electrical contact material comprising 0.05 to 8% by weight, the balance being silver.