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→Silver-Nickel (SINIDUR) Materials
Since silver and nickel are not soluble in each other in solid form and in the liquid phase have only very limited solubility silver nickel composite materials with higher Ni contents can only be produced by powder metallurgy. During extrusion of sintered Ag/Ni billets into wires, strips and rods the Ni particles embedded in the Ag matrix are stretched and oriented in the microstructure into a pronounced fiber structure ''(Figs. 2.75. and 2.76)''
The high density produced during hot extrusion aids the arc erosion resistance of these materials <xr id="tab:tab2.21"/> (Tab 2.21) and <xr id="tab:tab2.22"/> (Tab 2.22). The typical application of Ag/Ni contact materials is in devices for switching currents of up to 100A ''<xr id="tab:tab2.24"/> (Table 2.24)''. In this range they are significantly more erosion resistant than silver or silver alloys. In addition they exhibit with nickel contents <20 wt% a low and over their operational lifetime consistent contact resistance and good arc moving properties. In DC applications Ag/Ni materials exhibit a relatively low tendency of material transfer distributed evenly over the contact surfaces ''<xr id="tab:tab2.23"/> (Table 2.23)''.
Typically Ag/Ni (SINIDUR) materials are usually produced with contents of 10-40 wt% Ni. The most widely used materials SINIDUR 10 and SINIDUR 20- and also SINIDUR 15, mostly used in north america-, are easily formable and applied by cladding ''(Figs. 2.71-2.74)''. They can be, without any additional welding aids, economically welded and brazed to the commonly used contact carrier materials.
The most important applications for Ag/Ni contact materials are typically in relays, wiring devices, appliance switches, thermostatic controls, auxiliary
switches, and small contactors with nominal currents >20A ''<xr id="tab:tab2.24"/> (Table 2.24)''.
<figtable id="tab:tab2.21">
[[File:Micro structure of AgNi 8020.jpg|right|thumb|Micro structure of Ag/Ni 80/20 a) perpendicular to the extrusion direction b) parallel to the extrusion direction]]
<figtable id="tab:tab2.23">
'''Table 2.23: Contact and Switching Properties of Silver-Nickel (SINIDUR) Materials'''
|High arc erosion resistance at switching currents up to 100A,<br />Resistance against welding for starting current up to 100A,<br />low and over the electrical contact life nearly constant contact resistance for Ag/Ni 90/10 and Ag/Ni 80/20,<br />ow and spread-out material transfer under DC load,<br />non-conductive erosion residue on isolating components resulting in only minor change of the dielectric strength of switching devices,<br />good arc moving properties,<br />good arc extinguishing properties,<br />good or sufficient ductility depending on the Ni content,<br />easy to weld and braze
|}
</figtable>
<figtable id="tab:tab2.24">
'''Table 2.24: Application Examples and Forms of Supply for Silver-Nickel (SINIDUR) Materials'''
|> 100A
|}
</figtable>
==== Silver-Metal Oxide Materials Ag/CdO, Ag/SnO<sub>2</sub>, Ag/ZnO====
