A preparation method of silver-nickel-graphite electric contact with continuous decarburization layer on the side

Abstract

The invention discloses a method for preparing a silver-nickel-graphite electric contact with a continuous decarburization layer on the side, which comprises the following steps: (1) powder mixing, uniformly mixing silver powder, nickel powder and graphite powder; (2) initial press molding ; (3) sintering, sintering the compact under a reducing atmosphere; (4) repressing, repressing the sintered compact to obtain a recompact; (5) decarburization, placing the recompact Heating in compressed air for decarburization, thereby forming a continuous decarburization layer on its surface; (6) cutting or milling, dividing the decarburized silver-nickel graphite billet into two to obtain two contacts; or milling off one side silver layer to obtain a monolithic contact; (7) cleaning, the contact obtained in step (6) is subjected to grinding, polishing and drying; (8) annealing, the cleaned product is annealed in a reducing atmosphere, and passed Annealing restores the oxidized nickel back to the finished product. In the silver-nickel-graphite electric contact prepared by the invention, the graphite is distributed in an arbitrary structure, the contact has strong anti-welding ability; the side has a continuous decarburization layer, and the contact has a long mechanical life.

Description

A kind of preparation method of silver-nickel-graphite electrical contact with continuous decarburization layer on side technical field The present invention relates to the field of electrical contact material science, specifically refers to a kind of silver-nickel graphite with continuous decarburization layer on the side The preparation method of the electrical contact and the product thereof. Background technique [0002] The silver-nickel-graphite electrical contacts produced by powder metallurgy technology are mainly used in frame circuit breakers as static points. Depend on It is used to replace part of silver with nickel, and the material cost is relatively low. The processing technology of silver-nickel-graphite electrical contacts is mainly a molding process, which is the mixed powder of graphite powder, nickel powder and silver powder. It is filled into the cavity for single-piece pressing, and the compact is divided into two layers: the silver-nickel graphi...

AI Technical Summary

Problems solved by technology

[0004] At present, the static points of miniature circuit breakers are basically extruded silver graphite materials. The advantage is that the service life is long, and the disadvantage is that the material cost is high and the anti-welding ability is average.

Images