Silver Metal Oxide systems are used for heavier duty applications. They are suitable for switching currents up to 3000A.
Silver Cadmium Oxide
Cadmium Oxide confers an anti-welding property to an electrical contact. The higher the oxide content the more resistant to sticking or welding it becomes. Two different methods are used to manufacture these products – CADOSIL is produced from Silver Cadmium Oxide powders which are blended, compacted and sintered. The CADOSIL grades are predominantly supplied in wire form, their even structure being particularly suited to contact heading applications.
The CADOSIL SB grades are supplied in strip forms. GD materials are produced by the internal oxidation of a Silver Cadmium alloy. This product is typically supplied in sheet or strip form. The SB designation denotes that a Silver backing has been bonded to one side to assist subsequent joining processes. Silver Cadmium Oxide Tips are also available.
With increasing Cadmium Oxide content the arc-resistance, hardness and contact resistance increase as well as weld resistance, but there is also a decrease in the ductility and conductivity of the material. Silver Cadmium Oxide alloys are weld resistant up to 3000A and have low arc-erosion when switching 100 to 3000A. They have good arc-extinguishing properties which, above 70A, are better than other metal oxide systems.