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Tungsten and Molybdenum Based Materials

66 bytes added, 16:25, 28 April 2014
Silver–Molybdenum (SILMODUR) Materials
=== Silver–Molybdenum (SILMODUR) Materials===
Ag/Mo materials with typically 50-70 wt% molybdenum are usually produced by the powder metallurgical infiltration process <xr id="fig:fig2.137Micro structure of Ag Mo 35 65"/> (Fig. 2.137) <xr id="fig:Physical Properties of-Contact Materials Based"/> (Table 2.36)''. Their contact properties are similar to those of Ag/W materials <xr id="tab:Contact and Switching Properties of Contact Materials Based on Silver – Tungsten (SIWODUR), Silver–Tungsten Carbide (SIWODUR C) and Silver Molybdenum (SILMODUR)"/> (Table 2.37). Since the molybdenum oxide is thermally less stable than tungsten oxide the self-cleaning effect of Ag/Mo contact surface during arcing is more pronounced and the contact resistance remains lower than that of Ag/W. The arc erosion resistance of Ag/Mo however is lower than the one for Ag/W materials. The main applications for Ag/Mo contacts are in equipment protecting switching devices <xr id="tab:Contact and Switching Properties of Contact Materials Based on Silver – Tungsten (SIWODUR), Silver–Tungsten Carbide (SIWODUR C) and Silver Molybdenum (SILMODUR)"/> (Table 2.38).
<figure id="fig:Physical Properties of-Contact Materials Based">
<xr id="fig:Micro structure of -Ag WC 27 C3"/> Fig. 2.136: Micro structure of Ag/WC27/C3
<xr id="fig:fig2.137Micro structure of Ag Mo 35 65"/> Fig. 2.137: Micro structure of Ag/Mo 35/65
[[File:Micro structure of -Ag WC 27 C3.jpg|left|thumb|<caption>Micro structure of Ag/WC27/C3</caption>]]
</figure>
<figure id="fig:fig2.137Micro structure of Ag Mo 35 65">
[[File:Micro structure of Ag Mo 35 65.jpg|left|thumb|<caption>Micro structure of Ag/Mo 35/65</caption>]]
</figure>