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=== Seam–Welded Contact Strip Materials (FDR–Profiles)===
Seam–welding is the process by which the contact material in the form of a solid wire, narrow clad strip, or profile is attached to the carrier strip by overlapping or continuous weld pulses between rolling electrodes <xr id="fig:Seam-welding process (schematic)"/> <!--(Fig. 3.6)-->. The weld joint is created by simultaneous effects of heat and pressure. Except for the very small actual weld joint area the original hardness of the carrier strip is maintained because of the limited short time of the heat supply. Therefore also spring-hard base materials can be used without loss of their mechanical strength. The use of clad contact pre-materials and profiles allows to minimize the use of the costly precious metal component tailored to the need for optimum reliability over the expected electrical life of the contact components.
*Typical configurations of seam–welded contact strips and stamped parts (<xr id="fig:Typical configurations of seam-welded contact strips"/>)
<figure id="fig:Typical configurations of seam-welded contact strips">
[[File:Typical configurations of seam-welded contact strips.jpg|right|thumb|Typical configurations of seam-welded contact strips]]
*Carrier materials <br />Cu, CuSn, CuZn, CuNiZn, CuBe et al.<br />
*Dimensions (<xr id="fig:Contact Profiles Dimensions"/>)
<figure id="fig:Contact Profiles Dimensions">
[[File:Contact Profiles Dimensions.jpg|right|thumb|Contact Profiles Dimensions]]
Contact profiles in larger sizes are often used for switching devices in the low voltage technology. For these the contact layer mostly consists of arc erosion resistant materials such as silver–nickel, silver–metal oxides or the weld resistant silver– graphite. The brazable or weldable underside of the metal oxide or silver–graphite materials is usually pure silver with also quite often a thin layer of a phosphorous containing brazing alloy applied to aid the welding process.
*Typical configurations of multi-layer contact profiles (<xr id="fig:Typical configurations of multi-layer contact profiles"/>)
<figure id="fig:Typical configurations of multi-layer contact profiles">
[[File:Typical configurations of multi-layer contact profiles.jpg|right|thumb|Typical configurations of multi-layer contact profiles]]
*Quality criteria <br />Beause of the variety of configurations of contact profiles usually the quality issues are separately agreed upon between the manufacturer and the user.<br />
*Dimensions and tolerances (<xr id="fig:Contact Profiles Dimensions and tolerances"/>)
<figure id="fig:Contact Profiles Dimensions and tolerances">
[[File:Contact Profiles Dimensions and tolerances.jpg|right|thumb|Contact Profiles Dimensions and tolerances]]
</figure>
The thickness of the Au top-layer, which is sputtered for example, is between 0.2 and 5 μm, depending on the requirements. Tolerance of thickness is about ± 10%.
==References==
[[:Manufacturing Technologies for Contact Parts#References|References]]
[[de:Herstellung_von_Halbzeugen]]
