Powder metallurgy material properties
Craft:
At present, in the preparation process of contact materials, powder metallurgy has attracted more and more attention and has become the main manufacturing process of contact materials. This method can produce silver tungsten, copper tungsten, silver tungsten carbide, silver carbide Tungsten graphite, silver nickel, silver nickel graphite, silver graphite, silver metal oxide and other series of contact products. Its products have the following characteristics:
① The composition and quality of contact products prepared by powder metallurgy are easier to control than other process methods, which ensures the consistency of contact product performance. The powder process makes other component particles refined and evenly distributed in the silver or copper matrix, which is of great benefit to improving the metallographic structure of the contact material and improving the performance of the contact product.
② The silver-graphite contact product is produced by sintering extrusion process, and its density is as high as 99.9%. At the same time, the second component graphite is distributed in the form of fibers in the silver matrix, and the fiber arrangement direction is perpendicular or parallel to the surface of the electrical contact product, so that the The physical and mechanical properties of the material are greatly improved, and at the same time, the product has better electrical properties such as anti-fusion welding, arc burning resistance and low and stable contact resistance.
③ For contact products such as silver tungsten, silver tungsten carbide and copper tungsten, raw material powders with different particle sizes are selected, and trace elements such as nickel and cobalt are added. electrical properties.
application:
①Silver-graphite series: Mainly used for protection switches, such as miniature circuit breakers, leakage protection switches or engine protection switches, and silver-nickel or copper are commonly used for mating contacts.
②Silver-tungsten series: Mainly used for various universal circuit breakers, molded case circuit breakers, heavy-duty AC and DC contactors and other switching appliances.
③Silver tungsten carbide, silver tungsten carbide graphite series: Mainly used for switchgear with high current load, such as circuit breaker, leakage switch. In many cases it is used together with silver nickel or silver tungsten carbide.
④Copper-tungsten series: widely used in high-voltage circuit breakers.
⑤Silver-nickel series: Widely used in AC and DC relays, command switches, contactors, light-controlled switches, thermostats and timers of washing machines.
⑥Silver metal oxide series: Mainly used in medium and large capacity relays, contactors, medium and small capacity low-voltage circuit breakers, AC and DC switches, power protection switches, leakage protection switches, automotive electrical appliances, etc.