Method for preparing agni electrical contact material based on foaming infiltration process and product thereof

Abstract

The invention discloses a method and a product for preparing AgNi electrical contact materials based on a foaming infiltration process. The technical scheme is that a foaming agent is added to AgNi mixed powder for sintering strengthening, and the sintering-strengthened AgNi powder is wrapped with a separator and sintered Above the liquid phase, it is crushed and sieved to obtain high-strength porous AgNi powder. The porous AgNi powder is isostatically pressed into a special columnar porous skeleton ingot, and then the pure silver sheet is placed above the skeleton and placed in a graphite crucible. The skeleton ingot is infiltrated at high temperature to obtain AgNi / Ag composite ingot with high silver content and low resistivity, and the ingot is extruded into a thin strip and finally punched into AgNi electrical contact material. The invention simultaneously solves the problem of composite extrusion of thin strips and the problem that low-nickel and high-silver AgNi electrical contacts can only be made by solid-phase sintering process. The service life and other performance have been greatly improved.

Description

Technical field [0001] The invention involves the field of electrical contact materials, which specifically refers to a method and its products that prepare an AGNI electrical contact material. This process uses a new foam melting seepage process for preparation. Background technique [0002] The AGNI electrical contact material has many applications in circuit breakers, micro-circuit breakers, leakage protection switches, contactors, and relays. Generally, the sintering sintering method or extrusion method is used. The NI content is between 10WT % -35WT %. The requirements for the switching temperature in the switch design are getting higher and higher, especially in small micro -breaking materials, the Ni content is more than 35WT % of the material contact contact resistance, it is difficult to meet the use requirements, and the electric contact material with low NI content can only be used in solids. The sintering method cannot meet the requirements of switching and short circ...

AI Technical Summary

Problems solved by technology

[0011] The Chinese invention patent with the publication number CN104209520A adds a polyacrylate pore-forming agent to the powder to increase the pores. The powder produced by this method has low strength and can meet the production requirements when making AgNi30 and AgNi materials with higher Ni content. When making AgNi materials with a Ni content below 30%, the skeleton will collapse or even burst due to the severe deformation of the pores during the infiltration process.

Similarly, using this method to make high-silver AgNi materials will also have the problem that the skeleton collapses or even bursts during infiltration and cannot be formed.

[0012] The Chinese invention patent with the publication number CN112548099A provides a method for making porous alloy powder by using ammonium bicarbonate foaming agent. The powder made by this method also has the problem that the internal strength of the powder is too low. During the AgNi infiltration process, the powder will cause the skeleton to collapse or even explode due to the severe deformation of the pores, and the mechanism is basically similar to that of the polyacrylate pore-forming agent.

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