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The family of silver-metal oxide contact materials includes the material groups: silver-cadmium oxide, silver-tin oxide, and silverzinc oxide. Because of their very good contact and switching properties like high resistance against welding, low contact resistance, and high arc erosion resistance, silver-metal oxides have gained an outstanding position in a broad field of applications. They are mainly used in low voltage electrical switching devices like relays, installation and distribution switches, appliances, industrial controls, motor controls, and protective devices (<xr id="tab:Application Examples of Silver–Metal Oxide Materials"/>)<!--(Table 2.31)-->.

Silver-cadmium oxide materials with 10-15 wt% are produced by both, internal oxidation and powder metallurgical methods (<xr id="tab:Physical and Mechanical Properties"/>)<!--(Table 2.25)-->.

The manufacturing of strips and wires by internal oxidation starts with a molten alloy of silver and cadmium. During a heat treatment below it's melting point in an oxygen rich atmosphere of such a homogeneous alloy, the oxygen diffuses from the surface into the bulk of the material and oxidizes the Cd to CdO in a more or less fine particle precipitation inside the Ag matrix. The CdO particles are rather fine in the surface area and getting larger towards the center of the material (<xr id="fig:Micro structure of AgCdO9010"/>)<!--(Fig. 2.83)-->.

During the manufacturing of Ag/CdO contact material by internal oxidation, the processes vary depending on the type of semi-finished material. For Ag/CdO wires, a complete oxidation of the AgCd wire is performed, followed by wire-drawing to the required diameter (<xr id="fig:Strain hardening of internally oxidized AgCdO9010"/><!--(Figs. 2.77)--> and <xr id="fig:Softening of internally oxidized AgCdO9010"/>)<!--(Fig. 2.78)-->. The resulting material is used for example, in the production of contact rivets. For Ag/CdO strip materials two processes are commonly used: Cladding of an AgCd alloy strip with fine silver, followed by complete oxidation, results in a strip material with a small depletion area in the center of it's thickness and an Ag backing suitable for easy attachment by brazing (sometimes called "Conventional Ag/CdO"). Using a technology that allows the partial oxidation of a dual-strip AgCd alloy material in a higher pressure pure oxygen atmosphere, yields a composite Ag/CdO strip material that has - besides a relatively fine CdO precipitation - also an easily brazable AgCd alloy backing <xr id="fig:Micro structure of AgCdO9010ZH"/><!--(Fig. 2.85)-->. These materials are mainly used as the basis for contact profiles and contact tips.

During powder metallurgical production, the powder mixed made by different processes are typically converted by pressing, sintering and extrusion to wires and strips. The high degree of deformation during hot extrusion, produces a uniform and fine dispersion of CdO particles in the Ag matrix while at the same time achieving a high density which is advantageous for good contact properties (<xr id="fig:Micro structure of AgCdO9010P"/>)<!--(Fig. 2.84)-->. To obtain a backing suitable for brazing, a fine silver layer is applied by either com-pound extrusion or hot cladding prior to or right after the extrusion <xr id="fig:Micro structure of AgCdO8812WP"/><!--(Fig. 2.86)-->.