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→Composite Contact Rivets
During ''cold bonding'' the process of heading the bond between the contact material and the copper is achieved without external heat energy by high plastic deformation at the face surfaces of the two wire segments (<xr id="fig:Cold_bonding_of_bimetall_rivets"/><!--(Fig. 3.1)-->).
The bonding pressure must be high enough to move the lattice components of the two metals within a few atom radii, so that the adhesion forces between atoms become effective.
Therefore the head to shank diameter ratio of 2:1 must be closely met for a strong bond between the two metals.
During ''hot bonding'' the required heat energy is applied by a short term electrical current pulse (<xr id="fig:Hot_bonding_of_bimetal_rivets"/><!--(Fig. 3.2)-->).
In the case of Ag and Cu a molten eutectic alloy of silver and copper is formed in the constriction area between the two wire ends. When using metal oxide containing contact materials, the non-soluble oxide particles tend to coagulate and the bonding strength between the component materials is greatly reduced. Therefore the cold bonding technology is preferred for these contact materials. During cold bonding, the required high surface deformation ratio can be reduced for the hot bonding process which allows the head to shank diameter ratio to be reduced below 2:1.
*Typical contact shapes for composite rivets (<xr id="fig:Typical_contact_shapes_for_composite_rivets"/>)
*Contact materials <br /> Ag, AgNi 0,15 (ARGODUR), AgCu, AgCuNi (ARGODUR 27), Ag/Ni (SINIDUR), Ag/CdO (DODURIT CDO), Ag/SnO<sub>2</sub> (SISTADOX), Ag/ZnO (DODURIT ZNO)<br />
*Dimensional ranges (<xr id="fig:Dimensional_ranges"/>) <br />These parameters cannot be chosen independently of each other. They depend mainly on the mechanical properties of the contact material. Before specifying the final dimensions we recommend to consult with the contact manufacturer. <br />
*Quality criteria and tolerances (<xr id="fig:Quality_criteria_and_tolerances"/>)
<div class="multiple-images">
<figure id="fig:Cold_bonding_of_bimetall_rivets">
[[File:Cold_bonding_of_bimetall_rivets.jpg|right|thumb|Figure 4: Cold bonding of bimetall rivets (schematic)]]
</figure>
<figure id="fig:Hot_bonding_of_bimetal_rivets">
[[File:Hot_bonding_of_bimetal_rivets.jpg|right|thumb|Figure 5: Hot bonding of bimetall rivets (schematic)]]
</figure>
<figure id="fig:Typical_contact_shapes_for_composite_rivets">
[[File:Typical_contact_shapes_for_composite_rivets.jpg|right|thumb|Figure 6: Typical contact shapes for composite rivets]]
</figure>
<figure id="fig:Dimensional_ranges">
[[File:Dimensional_ranges.jpg|right|thumb|Figure 7: Dimensional ranges]]
</figure>
<figure id="fig:Quality_criteria_and_tolerances">
[[File:Quality_criteria_and_tolerances.jpg|left|thumb|Figure 8: Quality criteria and tolerances]]
</figure>
</div>
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