Semi-finished contact pre-materials can be manufactured from solid preciousmetals, precious metal alloys, or precious metal containing composite materials.They are made in wire, strip, and profile form by known processing technologiessuch as extrusion and subsequent annealing and drawing or roll-forming. Theyare supplied following the manufacturer's internal standards usually related toDIN EN specifications for copper based materials. The most important materialsare two – or multiple material layered semi-finished materials with the contactmaterial bonded in its solid phase to non-precious carriers by cladding, brazing,or welding. The contact material can also be deposited on the carrier from the

Clad materials consist of two or more layers of different materials, the contactmaterial and the carrier, which are firmly bonded to each other. Depending onthe electrical requirements the contact material is mainly an alloy of gold,palladium, or silver based , while the carrier material are mainly copper alloys. Tobond these materials , various technologies are utilized, the two most importantones being described in more detail below.

During ''hot cladding'', the classic process, the materials to be clad areassembled into a cladding package in block or plate form, heated to about800°C and clad (or “welded”"welded") together under high pressure ''(<xr id="fig:Hot_cladding_of_pre_materials"/><!--(Fig. 3.3)''-->). At theinterface between the two materials , a non-separable bond is formed by eitherdiffusion of the reaction partners or in liquid phase by forming a AgCu eutecticalloy when an additional brazing alloy foil is placed between the two materials.Further processing is done by rolling with required annealing steps betweensubsequent thickness reductions. The disadvantage of this process is theusually limited short length of final material strips.

In the ''Cold Roll-Cladding'' process, the bond between the contact and carrier material is achieved by cold deformation of > 50% in one rolling pass (<xr id="fig:Cold roll-cladding of semi-finished strips (schematic)"/><!-- (Fig. 3.3: Hot cladding 4)-->). The high plastic deformation causes cold welding in the boundary layer between the two materials. To increase the quality and strength of prethe bond, a subsequent diffusion annealing is performed in most cases. This process is most suitable for clad semi-materials finished strips with thin contact material layers (&ge; 2 μm) and large strip length (schematic> 100 m).

In the ''Cold Roll-Cladding'' process the bond between the *Typical configurations of clad contact and carriermaterial is achieved by cold deformation of > 50% in one rolling pass ''strips (Fig. 3.4)''.The high plastic deformation causes cold welding in the boundary layer betweenthe two materials. To increase the quality and strength <xr id="fig:Typical configurations of the bond a subsequentdiffusion annealing is performed in most cases. This process is most suitable forclad semi-finished contact strips with thin contact material layers (> 2 μm) and large striplength ("/> 100 m).

Fig. 3*Contact materials <br />Ag, Ag-alloys.4: Cold roll-cladding of semi-finished strips (schematic), Ag/Ni, in special cases also Ag/SnO₂ and Ag/ZnO <br />

*Typical configurations of clad contact stripsbildCarrier materials: Cu, CuSn, CuNiZn, CuNiSn, CuFe, CuBe et al.

*Contact materials <br />Ag, Ag-alloys., Ag/Ni Dimensions (SINIDUR), in special cases also Ag/CdO (DODURIT CdO), Ag/SnO<sub>2<xr id="fig:Dimensions"/sub> (SISTADOX), Ag/ZnO (DODURIT ZnO)<br />

*Carrier materialskein text *DimensionsbildWhen specifying the contact material layer thickness it is recommended to use theminimum required thickness.

Strength properties and dimensional tolerances of clad contact bi-metals arederived from the standards DIN EN 1652 and DIN EN 1654 for Cu alloys. Whenspecifying the width of the contact material layer , it is recommended to use theminimum required value. All dimensions should be specified originating from onestrip edge.

<div class="multiple-images"><figure id= Brazed Semi"fig:Hot_cladding_of_pre_materials">[[File:Hot cladding of pre-Finished Contact Materials materials (Toplay–Profilesschematisch)==.jpg|right|thumb|Figure 1: Hot cladding of pre-materials (schematic)]]The toplay process starts with a flat or profile – shaped contact material strip</figure>which is fed together with the wider non<figure id="fig:Cold roll-cladding of semi-precious carrier material and in mostfinished strips (schematic)">cases an intermediate thin foil [[File:Cold roll-cladding of brazing alloy into a induction brazing machine''semi-finished strips (Figschematic). 3.5jpg|right|thumb|Figure 2: Cold roll-cladding of semi-finished strips (schematic)''. An evenly distributed and reliable braze joint can be achieved this way]]</figure><figure id="fig:Typical configurations of clad contact strips">between [[File:Typical configurations of clad contact and carrier materialsstrips. The combined material strip is rather softjpg|right|thumb|Figure 3: Typical configurations of clad contact strips]]after the brazing process and re-hardened during a subsequent profile rolling</figure><figure id="fig:Dimensions">step. In this way different shapes and configurations can easily be achieved[[File:Dimensions.jpg|right|thumb|Figure 4: Dimensions]]</figure></div><div class="clear"></div>

Fig. 3.5=== Brazed Semi-Finished Contact Materials (Toplay–Profiles)===The toplay process starts with a flat or profile – shaped contact material strip which is fed together with the wider non-precious carrier material and in most cases an intermediate thin foil of brazing alloy into a induction brazing machine (<xr id="fig: Toplay brazing with an inductive heating inline equipment (schematic)"/><!--(Fig. 3.5)-->). An evenly distributed and reliable braze joint can be achieved this way between contact and carrier materials. The combined material strip is rather soft after the brazing process and re-hardened during a subsequent profile rolling step. In this way different shapes and configurations can easily be achieved.

*Typical configurations of toplay contact profilesbild(<xr id="fig:Typical configurations of toplay contact profiles2"/>)

*Contact materials <br />Ag, AgNi 0,15 (ARGODUR), AgCu, AgCuNi (ARGODUR 27), Ag/Ni (SINIDUR),Ag/CdO (DODURIT CdO), Ag/SnO₂ (SISTADOX), and Ag/ZnO (DODURIT ZnO)<br />

*Carrier materials <br />: Cu, CuZn, CuSn et al.<br />

*Quality criteria, dimensions and tolerancesbild(<xr id="fig:Quality criteria dimensions and tolerances"/>)

Strength properties and dimensional tolerances of toplay profiles are derivedfrom the standards DIN EN 1652 and DIN EN 1654 for Cu alloys.

<div class="multiple-images"><figure id= Seam–Welded Contact Strip Materials "fig:Toplay brazing with an inductive heating inline equipment (FDR–Profilesschematic)==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 orcontinuous weld pulses between rolling electrodes ''[[File:Toplay brazing with an inductive heating inline equipment (Figschematic). 3.6jpg|right|thumb|Figure 5: Toplay brazing with an inductive heating inline equipment (schematic)''. The weld joint is]]created by simultaneous effects of heat and pressure. Except for the very small</figure>actual weld joint area the original hardness <figure id="fig:Typical configurations of the carrier strip is maintainedtoplay contact profiles2">because [[File:Typical configurations of the limited short time of the heat supplytoplay contact profiles2. Therefore also spring-hardbase materials can be used without loss of their mechanical strength. The use jpg|right|thumb|Figure 6: Typical configurations ofclad toplay contact pre-materials and profiles allows to minimize the use of the costly]]</figure>precious metal component tailored to the need for optimum reliability over the<figure id="fig:Quality criteria dimensions and tolerances">expected electrical life of the contact components[[File:Quality criteria dimensions and tolerances.jpg|right|thumb|Figure 7: Quality criteria dimensions and tolerances]]</figure></div><div class="clear"></div>

*Typical configurations === Contact Profiles (Contact Weld Tapes)===Contact profiles span a broad range of seam–welded contact strips dimensions. Width and thickness are typically between 0.8 – 8.0 mm and stamped partsbildFig0. 2 – 3.6: Seam0 mm resp. Special configurations, often defined as miniature-welding process (schematic)profiles or even micro–profiles can have a width < 2.0 mm.

*Contact materials <br />AuMiniature–profiles are mostly composed of a contact-Alloysbimetal material with the contact material being a precious metal alloy or composite material clad, Pdwelded or coated by electroplating or vacuum-Alloys, Ag, AgNi 0,15 deposition (ARGODURsputtered)onto a weldable base material. Since these profiles are attached to carrier strip materials, AgCuusually by segment– or seam– welding to the base materials, AgCuNi (ARGODUR 27)materials with good welding properties such as nickel, Ag/Ni (SINIDUR)copper-nickel, Ag/CdO (DODURIT CdO)copper-tin, Ag/SnO₂ (SISTADOX), Ag/ZnO (DODURIT ZnO)<br />as well as copper-nickel-zinc alloys are used. The bottom surface of the profiles usually has formed weld rails or similar patterns to ensure a solid continuous metallurgical weld joint between the profile and the contact carrier.

*Carrier 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 <br />Cusuch as silver–nickel, CuSn, CuZn, CuNiZn, CuBe et alsilver–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.<br />

*DimensionsbildTypical configurations of multi-layer contact profiles (<xr id="fig:Typical configurations of multi-layer contact profiles"/>)

*Quality criteria and tolerancesStrength properties and dimensional tolerances of toplay profiles are derived from thestandards DIN EN 1652 and DIN EN 1654 for Cu alloys.. == Contact Profiles (Contact Weld Tapes)==Contact profiles span a broad range of dimensions. Width and thickness are typicallybetween 0.8 – 8.0 mm and 0.2 – 3.0 mm resp. Special configurations, often definedas miniature-profiles or even micro–profiles can have awidth < 2.0 mm. Miniature–profiles are mostly composed of a contact-bimetal material with the contactmaterial being a precious metal alloy or composite material clad, welded or coated byelectroplating or vacuum-deposition (sputtered) onto a weldable base material. Sincethese profiles are attached to carrier strip materials usually by segment– or seam–welding to the base materials, materials with good welding properties such as nickel,copper-nickel, copper-tin, as well as copper-nickel-zinc alloys are used. The bottomsurface of the profiles usually has formed weld rails or similar patterns to ensure asolid continuous metallurgical weld joint between the profile and the contact carrier. Contact profiles in larger sizes are often used for switching devices in the low voltagetechnology. For these the contact layer mostly consists of arc erosion resistantmaterials such as silver–nickel, silver–metal oxides or the weld resistant silver–graphite. The brazable or weldable underside of the metal oxide or silver–graphitematerials is usually pure silver with also quite often a thin layer of a phosphorouscontaining brazing alloy applied to aid the welding process. *Typical configurations of multi-layer contact profilesbild *Contact materials <br />Au-Alloys, Pd-Alloys, Ag-Alloys, Ag/Ni (SINIDUR), Ag/CdO (DODURIT CdO), Ag/SnO₂ (SISTADOX), Ag/ZnO (DODURIT ZnO)<br />

*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"/>)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 &plusmn; 10%.

*Dimensions and tolerances <br /div class="multiple-images"><figure id="fig:Typical configurations of multi-layer contact profiles">The thickness [[File:Typical configurations of the Au topmulti-layer, which is sputtered for example, is between 0contact profiles.2 and 5 μm, depending on the requirements. Tolerance jpg|right|thumb|Figure 8: Typical configurations of thickness is about + 10%.multi-layer contact profiles]]<br /figure>bild<figure id="fig:Contact Profiles Dimensions and tolerances">[[CategoryFile:Manufacturing Technologies for Contact PartsProfiles Dimensions and tolerances.jpg|right|thumb|CategoryFigure 9: Contact Profiles Dimensions and tolerances]]</figure></div><div class="clear"></div>