Silver nickel graphite composite contact terminal material and processing method thereof

Abstract

The invention discloses a processing method of a silver nickel graphite composite contact terminal material, and the processing method is characterized by comprising the steps of preparing silver powder, nickel powder and graphite powder contained by the silver nickel graphite composite contact terminal material, respectively preparing the silver powder and the nickel powder into nickel nitrate solution and silver nitrate solution, placing the nickel nitrate solution and the silver nitrate solution into a reactor vessel, injecting sodium hydroxide (NaOH) solution under the blending situation, precipitating silver oxide (Ag2O) plus nickelous hydroxide (Ni(OH)2) co-precipitated powder, after the co-precipitated powder is washed, dried and reduced, graphite powder is placed in to the co-precipitated powder, and finally the silver nickel graphite composite contact terminal material is obtained through steps of wet ball milling, vacuum drying, annealing, primary press forming, sintering, re-pressing, annealing, re-pressing and surface treatment. The distribution of nickel and graphite particles in a silver substrate can be improved by utilizing chemical co-precipitation process and wet ball milling process, the physical combination strength of wet materials can be improved, and the mechanical performance, the physical performance and electric performance of the material can be improved. The metallographic structure of the material is uniform and fine, the produced contact terminal material has large density, the conductivity is greatly optimized, and the electric arc corrosion resistance can be improved.

Description

technical field [0001] The invention relates to a production process method of a silver-nickel-graphite electrical contact material used for manufacturing electrical contacts used in electrical switches such as various molded case circuit breakers and frame-type universal circuit breakers. Background technique [0002] Among the electrical contact materials of low-voltage electrical appliances, silver-nickel-graphite contact materials are mainly used in various molded case circuit breakers and frame-type universal circuit breakers. This is because the material has good welding resistance and electrical conductivity, low and stable contact resistance. The role of graphite is to prevent the bonding and welding of the contacts, and does not form any insulation to increase the contact resistance. However, graphite has a stable arc inclination and poor thermal stability in the air. Because the existing silver-nickel graphite contact materials do not pay attention to graphite...

AI Technical Summary

Problems solved by technology

However, graphite has a stable arc inclination and poor thermal stability in the air. Because the existing silver-nickel graphite contact materials do not pay attention to graphite content and processing technology during processing, poor arc corrosion resistance is the biggest defect of this material.

At present, the mechanical powder mixing process is generally used for production. This process is simple and easy, with few processes, low equipment requirements, high material utilization rate, and low production cost. However, the obtained contacts have uneven structure, poor compactness, and arc high erosion rate