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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"/> (Tables 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 ''(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 ''(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.
switches, and small contactors with nominal currents >20A ''(Table 2.24)''.
<figtable id="tab:tab2.21">
'''Table 2.21: Physical Properties of Silver-Nickel (SINIDUR) Materials'''
<table border="1" cellspacing="0" style="border-collapse:collapse"><tr><td><p class="s12">Material/</p><p class="s11">DODUCO <span style=" color: #151616;">Designation</span></p></td><td><p class="s12">Silver Content</p><p class="s12">[wt%]</p></td><td><p class="s12">Density</p><p class="s11">[g/cm<span class="s13">3 </span><span style=" color: #151616;">]</span></p></td><td><p class="s12">Melting Point</p><p class="s12">[°C]</p></td><td><p class="s12">Electrical</p><p class="s12">Resistivity <i>p</i></p><p class="s11">[µ<span class="s14">S ·</span>cm]</p></td><td><p class="s12">Electrical Resistivity</p><p class="s11">(soft)</p></td></tr><tr><td><p class="s12">Material/</p><p class="s11">DODUCO <span style=" color: #151616;">Designation</span></p></td><td><p class="s12">Silver Content</p><p class="s12">[wt%]</p></td><td><p class="s12">Density</p><p class="s11">[g/cm<span class="s13">3 </span><span style=" color: #151616;">]</span></p></td><td><p class="s12">Melting Point</p><p class="s12">[°C]</p></td><td><p class="s12">Electrical</p><p class="s12">Resistivity <i>p</i></p><p class="s11">[µ<span class="s14">S ·</span>cm]</p></td><td><p class="s11">[% IACS]</p></td><td><p class="s11">[MS/m]</p></td></tr><tr><td><p class="s11">Ag/Ni 90/10</p><p class="s11">SINIDUR 10</p></td><td><p class="s11">89 - 91</p></td><td><p class="s11">10.2 - 10.3</p></td><td><p class="s11">960</p></td><td><p class="s11">1.82 - 1.92</p></td><td><p class="s12">90 - 95</p></td><td><p class="s12">52 - 55</p></td></tr><tr><td><p class="s11">Ag/Ni 85/15</p><p class="s11">SINIDUR 15</p></td><td><p class="s11">84 - 86</p></td><td><p class="s11">10.1 - 10.2</p></td><td><p class="s11">960</p></td><td><p class="s11">1.89 - 2.0</p></td><td><p class="s12">86 - 91</p></td><td><p class="s12">50 - 53</p></td></tr><tr><td><p class="s11">Ag/Ni 80/20</p><p class="s11">SINIDUR 20</p></td><td><p class="s11">79 - 81</p></td><td><p class="s11">10.0 - 10.1</p></td><td><p class="s11">960</p></td><td><p class="s11">1.92 - 2.08</p></td><td><p class="s12">83 - 90</p></td><td><p class="s12">48 - 52</p></td></tr><tr><td><p class="s11">Ag/Ni 70/30</p><p class="s11">SINIDUR 30</p></td><td><p class="s11">69 - 71</p></td><td><p class="s11">9.8</p></td><td><p class="s11">960</p></td><td><p class="s11">2.44</p></td><td><p class="s12">71</p></td><td><p class="s12">41</p></td></tr><tr><td><p class="s11">Ag/Ni 60/40</p><p class="s11">SINIDUR 40</p></td><td><p class="s11">59 - 61</p></td><td><p class="s11">9.7</p></td><td><p class="s11">960</p></td><td><p class="s11">2.70</p></td><td><p class="s12">64</p></td><td><p class="s12">37</p></td></tr></table>
</figtable>
<figtable id="tab:tab2.22">
'''Table 2.22: Mechanical Properties of Silver-Nickel (SINIDUR) Materials'''
|90<br />110<br />130<br />150
|}
</figtable>
Fig. 2.71: Strain hardening of Ag/Ni 90/10 by cold working
