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Views: 348 Author: Site Editor Publish Time: 2022-04-20 Origin: Site
As we all know, silver contacts parts are the heart of electrical appliances, and the quality of their welding has a great influence on the performance of electrical appliances. At present, the research on welding equipment, welding methods, welding process and other welding-related research is continuously deepening. Among them, improving the stability, reliability and energy saving of welding, and automation is the research direction. High-energy beam welding including electron beam welding and laser welding, friction welding, ultrasonic welding, diffusion welding, and inverter welding etc. are the current new cutting-edge technologies.
Generally the material of standard silver contact part is pure silver, which has the advantages of high electrical conductivity and thermal conductivity. It has a very low contact resistance, and is easy to process and easy to weld, so it is the best ideal material for making continuous closed electrical connections by far. At present, it is also one of the most common used materials for contacts in small-capacity low-voltage electrical appliances, such as automatic control switch, thermostat, baking machine, oven, timer, etc.
As above mentioned, silver has the best electrical and thermal conductivity among all metals, and it has excellent processing performance, and high oxidation resistance. The early electrical contact materials mostly used pure silver, but the hardness of silver is not high, and the melting point is low, and it is not wear-resistant, it will interact with the medium containing sulfur and sulfide under humidity and high temperature. So, a silver sulfide film is formed. In order to overcome various shortcomings of silver electrical contact materials, silver-based oxide electrical contact materials have been developed.
For composite silver contact or copper composite contact stamped part, their electrical conductivity of contact part is extremely good, and the surface is not easy to oxidize. If copper is added 3 - 28%, the burning resistance of silver can be significantly improved. Therefore, the material of contact part with copper can be applied to current strength up to 16A. Due to the high copper content such as 10%, the addition of copper can reduce the material transfer phenomenon under DC working conditions. Such good materials are widely used in the entire field of electrical switches, such as AC contactors, relays, power tool switches, buttons, timers and household appliances etc.
The material of electrical contacts for electrical appliances is generally silver alloys, and the content ranges from a few percent to seventy to eighty percent. The silver contacts for medium and small loads are pure, and the heavy loads include silver-cadmium oxide, silver-nickel, and silver-graphite contacts parts with a silver content of 90-95%. The materials in the fuse are pure silver, pure copper, and pure aluminum.
What is more, practical silver contacts components are widely used in dozens of thousands of electrical appliances such as wall switches, various relays, thermostats, small AC contactors, leakage protectors, power tool switches, and button switches and so on. The main materials used for silver contacts are silver, copper, iron and aluminum etc. Generally, it needs to be plated with silver to enhance its conductive effect and prevent oxidation.
