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→Silver-Metal Oxide Materials Ag/CdO, Ag/SnO2, Ag/ZnO
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:fig2.77"/> (Figs. 2.77) and <xr id="fig:fig2.78"/> (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 a 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 a easily brazable AgCd alloy backing <xr id="fig:fig2.85"/> (Fig. 2.85). These materials (DODURIT CdO ZH) 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 wiresand 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:fig2.84"/> (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:fig2.86"/> (Fig. 2.86).
For larger contact tips, and especially those with a rounded shape, the single tip Press-Sinter-Repress process (PSR) offers economical advantages. The
additives improve the wettability of the oxide particles and increase the viscosity of the Ag melt. They also provide additional benefits to the mechanical and arcing contact properties of materials in this group ''(Table 2.26)''.
'''Table 2.26: Physical and Mechanical Properties as well as Manufacturing Processes and Forms of Supply of Extruded Silver-Tin Oxide (SISTADOX) Contact Materials''' nicht gemacht! [[File:Physical Mechanical Properties as Manufacturing.jpg|right|thumb|Physical and Mechanical Properties as well as Manufacturing Processes andForms of Supply of Extruded Silver-Tin Oxide (SISTADOX) Contact Materials]]
In the manufacture the initial powder mixes different processes are applied which provide specific advantages of the resulting materials in respect to their contact properties <!--[[#figures|(Figs. 43 – 75)]]-->. Some of them are described here as follows: