Difference between revisions of "Manufacturing of Semi-Finished Materials"

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Semi-finished contact pre-materials can be manufactured from solid precious
+
Semi-finished contact pre-materials can be manufactured from solid precious metals, precious metal alloys, or precious metal containing composite materials. They are made in wire, strip, and profile form by known processing technologies such as extrusion and subsequent annealing and drawing or roll-forming. They are supplied following the manufacturer's internal standards usually related to DIN EN specifications for copper based materials. The most important materials are two – or multiple material layered semi-finished materials with the contact material 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
metals, precious metal alloys, or precious metal containing composite materials.
 
They are made in wire, strip, and profile form by known processing technologies
 
such as extrusion and subsequent annealing and drawing or roll-forming. They
 
are supplied following the manufacturer's internal standards usually related to
 
DIN EN specifications for copper based materials. The most important materials
 
are two – or multiple material layered semi-finished materials with the contact
 
material 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
 
 
liquid or vapor phase.
 
liquid or vapor phase.
  
 
===Clad Semi-Finished Pre-Materials (Contact-Bimetals)===
 
===Clad Semi-Finished Pre-Materials (Contact-Bimetals)===
Clad materials consist of two or more layers of different materials, the contact
+
Clad materials consist of two or more layers of different materials, the contact material and the carrier, which are firmly bonded to each other. Depending on the electrical requirements the contact material is mainly an alloy of gold, palladium, or silver based while the carrier material are mainly copper alloys. To bond these materials various technologies are utilized, the two most important ones being described in more detail below.
material and the carrier, which are firmly bonded to each other. Depending on
 
the electrical requirements the contact material is mainly an alloy of gold,
 
palladium, or silver based while the carrier material are mainly copper alloys. To
 
bond these materials various technologies are utilized, the two most important
 
ones being described in more detail below.
 
  
During ''hot cladding'', the classic process, the materials to be clad are
+
During ''hot cladding'', the classic process, the materials to be clad are assembled into a cladding package in block or plate form, heated to about
assembled into a cladding package in block or plate form, heated to about
+
800°C and clad (or "welded") together under high pressure <xr id="fig:Hot_cladding_of_pre_materials"/><!--(Fig. 3.3)-->. At the interface between the two materials a non-separable bond is formed by either diffusion of the reaction partners or in liquid phase by forming a AgCu eutectic alloy when an additional brazing alloy foil is placed between the two materials. Further processing is done by rolling with required annealing steps between subsequent thickness reductions. The disadvantage of this process is the usually limited short length of final material strips.
800°C and clad (or “welded”) together under high pressure ''(Fig. 3.3)''. At the
 
interface between the two materials a non-separable bond is formed by either
 
diffusion of the reaction partners or in liquid phase by forming a AgCu eutectic
 
alloy when an additional brazing alloy foil is placed between the two materials.
 
Further processing is done by rolling with required annealing steps between
 
subsequent thickness reductions. The disadvantage of this process is the
 
usually limited short length of final material strips.
 
 
 
Fig. 3.3 Hot cladding of pre-materials (schematic)
 
  
 +
<figure id="fig:Hot_cladding_of_pre_materials">
 
[[File:Hot cladding of pre-materials (schematisch).jpg|right|thumb|Hot cladding of pre-materials (schematisch)]]
 
[[File:Hot cladding of pre-materials (schematisch).jpg|right|thumb|Hot cladding of pre-materials (schematisch)]]
 +
</figure>
 +
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. 3.4)-->. The high plastic deformation causes cold welding in the boundary layer between the two materials. To increase the quality and strength of the bond a subsequent diffusion annealing is performed in most cases. This process is most suitable for clad semi-finished strips with thin contact material layers (&ge; 2 μm) and large strip length (> 100 m).
  
In the ''Cold Roll-Cladding'' process the bond between the contact and carrier
+
<figure id="fig:Cold roll-cladding of semi-finished strips (schematic)">
material is achieved by cold deformation of > 50% in one rolling pass ''(Fig. 3.4)''.
+
[[File:Cold roll-cladding of semi-finished strips (schematic).jpg|right|thumb|Cold roll-cladding of semi-finished strips (schematic)]]
The high plastic deformation causes cold welding in the boundary layer between
+
</figure>
the two materials. To increase the quality and strength of the bond a subsequent
 
diffusion annealing is performed in most cases. This process is most suitable for
 
clad semi-finished strips with thin contact material layers (> 2 μm) and large strip
 
length (> 100 m).
 
 
 
Fig. 3.4: Cold roll-cladding of semi-finished strips (schematic)
 
  
[[File:Cold roll-cladding of semi-finished strips (schematic).jpg|right|thumb|Cold roll-cladding of semi-finished strips (schematic)]]
+
*Typical configurations of clad contact strips <xr id="fig:Typical configurations of clad contact strips"/>
  
*Typical configurations of clad contact strips
+
<figure id="fig:Typical configurations of clad contact strips">
bild
+
[[File:Typical configurations of clad contact strips.jpg|right|thumb|Typical configurations of clad contact strips]]
 +
</figure>
  
 
*Contact materials <br />Ag, Ag-alloys., Ag/Ni (SINIDUR), in special cases also Ag/CdO (DODURIT CdO), Ag/SnO<sub>2</sub> (SISTADOX), Ag/ZnO (DODURIT ZnO)<br />
 
*Contact materials <br />Ag, Ag-alloys., Ag/Ni (SINIDUR), in special cases also Ag/CdO (DODURIT CdO), Ag/SnO<sub>2</sub> (SISTADOX), Ag/ZnO (DODURIT ZnO)<br />
  
 
*Carrier materials
 
*Carrier materials
kein text
 
  
*Dimensions
+
*Dimensions <xr id="fig:Dimensions"/>
bild
+
 
When specifying the contact material layer thickness it is recommended to use the
+
<figure id="fig:Dimensions">
minimum required thickness.
+
[[File:Dimensions.jpg|right|thumb|Dimensions]]
 +
</figure>
 +
When specifying the contact material layer thickness it is recommended to use the minimum required thickness.
  
 
*Quality criteria and tolerances
 
*Quality criteria and tolerances
Strength properties and dimensional tolerances of clad contact bi-metals are
+
Strength properties and dimensional tolerances of clad contact bi-metals are derived from the standards DIN EN 1652 and DIN EN 1654 for Cu alloys. When specifying the width of the contact material layer it is recommended to use the minimum required value. All dimensions should be specified originating from one strip edge.
derived from the standards DIN EN 1652 and DIN EN 1654 for Cu alloys. When
 
specifying the width of the contact material layer it is recommended to use the
 
minimum required value. All dimensions should be specified originating from one
 
strip edge.
 
  
 
=== Brazed Semi-Finished Contact Materials (Toplay–Profiles)===
 
=== Brazed Semi-Finished Contact Materials (Toplay–Profiles)===
The toplay process starts with a flat or profile – shaped contact material strip
+
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.
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
 
''(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.
 
  
Fig. 3.5: Toplay brazing with an inductive heating inline equipment (schematic)
+
<figure id="fig:Toplay brazing with an inductive heating inline equipment (schematic)">
 +
[[File:Toplay brazing with an inductive heating inline equipment (schematic).jpg|right|thumb|Toplay brazing with an inductive heating inline equipment (schematic)]]
 +
</figure>
  
*Typical configurations of toplay contact profiles
+
*Typical configurations of toplay contact profiles <xr id="fig:Typical configurations of toplay contact profiles2"/>
bild
 
  
 +
<figure id="fig:Typical configurations of toplay contact profiles2">
 +
[[File:Typical configurations of toplay contact profiles2.jpg|right|thumb|Typical configurations of toplay contact profiles]]
 +
</figure>
 
*Contact materials <br />Ag, AgNi 0,15 (ARGODUR), AgCu, AgCuNi (ARGODUR 27), Ag/Ni (SINIDUR),
 
*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 />
 
Ag/CdO (DODURIT CdO), Ag/SnO<sub>2</sub> (SISTADOX), Ag/ZnO (DODURIT ZnO)<br />
Line 83: Line 54:
 
*Carrier materials <br />Cu, CuZn, CuSn et al.<br />
 
*Carrier materials <br />Cu, CuZn, CuSn et al.<br />
  
*Quality criteria, dimensions and tolerances
+
*Quality criteria, dimensions and tolerances <xr id="fig:Quality criteria dimensions and tolerances"/>
bild
 
  
Strength properties and dimensional tolerances of toplay profiles are derived
+
<figure id="fig:Quality criteria dimensions and tolerances">
from the standards DIN EN 1652 and DIN EN 1654 for Cu alloys.
+
[[File:Quality criteria dimensions and tolerances.jpg|right|thumb|Quality criteria dimensions and tolerances]]
 +
</figure>
 +
Strength properties and dimensional tolerances of toplay profiles are derived from the standards DIN EN 1652 and DIN EN 1654 for Cu alloys.
  
 
=== Seam–Welded Contact Strip Materials (FDR–Profiles)===
 
=== Seam–Welded Contact Strip Materials (FDR–Profiles)===
Seam–welding is the process by which the contact material in the form of a solid
+
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.
wire, narrow clad strip, or profile is attached to the carrier strip by overlapping or
 
continuous weld pulses between rolling electrodes ''(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
+
*Typical configurations of seam–welded contact strips and stamped parts <xr id="fig:Typical configurations of seam-welded contact strips"/>
bild
+
<figure id="fig:Typical configurations of seam-welded contact strips">
Fig. 3.6: Seam-welding process (schematic)
+
[[File:Typical configurations of seam-welded contact strips.jpg|right|thumb|Typical configurations of seam-welded contact strips]]
 +
</figure>
 +
 
 +
<figure id="fig:Seam-welding process (schematic)">
 +
[[File:Seam-welding process (schematic).jpg|right|thumb|Seam-welding process (schematic)]]
 +
</figure>
  
 
*Contact materials <br />Au-Alloys, Pd-Alloys, 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 />
 
*Contact materials <br />Au-Alloys, Pd-Alloys, 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 />
Line 109: Line 77:
 
*Carrier materials <br />Cu, CuSn, CuZn, CuNiZn, CuBe et al.<br />
 
*Carrier materials <br />Cu, CuSn, CuZn, CuNiZn, CuBe et al.<br />
  
*Dimensions
+
*Dimensions <xr id="fig:Contact Profiles Dimensions"/>
bild
+
<figure id="fig:Contact Profiles Dimensions">
 +
[[File:Contact Profiles Dimensions.jpg|right|thumb|Contact Profiles Dimensions]]
 +
</figure>
  
 
*Quality criteria and tolerances
 
*Quality criteria and tolerances
Strength properties and dimensional tolerances of toplay profiles are derived from the
+
Strength properties and dimensional tolerances of toplay profiles are derived from the standards DIN EN 1652 and DIN EN 1654 for Cu alloys..
standards DIN EN 1652 and DIN EN 1654 for Cu alloys..
 
  
 
=== Contact Profiles (Contact Weld Tapes)===
 
=== Contact Profiles (Contact Weld Tapes)===
Contact profiles span a broad range of dimensions. Width and thickness are typically
+
Contact profiles span a broad range of dimensions. Width and thickness are typically between 0.8 – 8.0 mm and 0.2 – 3.0 mm resp. Special configurations, often defined as miniature-profiles or even micro–profiles can have a width < 2.0 mm.
between 0.8 – 8.0 mm and 0.2 – 3.0 mm resp. Special configurations, often defined
 
as miniature-profiles or even micro–profiles can have a
 
width < 2.0 mm.
 
  
Miniature–profiles are mostly composed of a contact-bimetal material with the contact
+
Miniature–profiles are mostly composed of a contact-bimetal material with the contact material being a precious metal alloy or composite material clad, welded or coated by electroplating or vacuum-deposition (sputtered) onto a weldable base material. Since these 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 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.
material being a precious metal alloy or composite material clad, welded or coated by
 
electroplating or vacuum-deposition (sputtered) onto a weldable base material. Since
 
these 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 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.
 
  
Contact profiles in larger sizes are often used for switching devices in the low voltage
+
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.
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
+
*Typical configurations of multi-layer contact profiles <xr id="fig:Typical configurations of multi-layer contact profiles"/>
bild
+
<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]]
 +
</figure>
  
 
*Contact materials <br />Au-Alloys, Pd-Alloys, Ag-Alloys, Ag/Ni (SINIDUR), Ag/CdO (DODURIT CdO), Ag/SnO<sub>2</sub> (SISTADOX), Ag/ZnO (DODURIT ZnO)<br />
 
*Contact materials <br />Au-Alloys, Pd-Alloys, Ag-Alloys, Ag/Ni (SINIDUR), Ag/CdO (DODURIT CdO), Ag/SnO<sub>2</sub> (SISTADOX), Ag/ZnO (DODURIT ZnO)<br />
Line 149: Line 105:
 
*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 />
 
*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 <br />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%.<br />
+
*Dimensions and tolerances <xr id="fig:Contact Profiles Dimensions and tolerances"/>
bild
+
<figure id="fig:Contact Profiles Dimensions and tolerances">
[[Category:Manufacturing Technologies for Contact Parts|Category]]
+
[[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 &plusmn; 10%.
  
 
==References==
 
==References==
 
[[:Manufacturing Technologies for Contact Parts#References|References]]
 
[[:Manufacturing Technologies for Contact Parts#References|References]]
 +
 +
[[de:Herstellung_von_Halbzeugen]]

Revision as of 13:16, 21 September 2014

Semi-finished contact pre-materials can be manufactured from solid precious metals, precious metal alloys, or precious metal containing composite materials. They are made in wire, strip, and profile form by known processing technologies such as extrusion and subsequent annealing and drawing or roll-forming. They are supplied following the manufacturer's internal standards usually related to DIN EN specifications for copper based materials. The most important materials are two – or multiple material layered semi-finished materials with the contact material 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 liquid or vapor phase.

Clad Semi-Finished Pre-Materials (Contact-Bimetals)

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

During hot cladding, the classic process, the materials to be clad are assembled into a cladding package in block or plate form, heated to about 800°C and clad (or "welded") together under high pressure Figure 1. At the interface between the two materials a non-separable bond is formed by either diffusion of the reaction partners or in liquid phase by forming a AgCu eutectic alloy when an additional brazing alloy foil is placed between the two materials. Further processing is done by rolling with required annealing steps between subsequent thickness reductions. The disadvantage of this process is the usually limited short length of final material strips.

Hot cladding of pre-materials (schematisch)

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 Figure 2. The high plastic deformation causes cold welding in the boundary layer between the two materials. To increase the quality and strength of the bond a subsequent diffusion annealing is performed in most cases. This process is most suitable for clad semi-finished strips with thin contact material layers (≥ 2 μm) and large strip length (> 100 m).

Cold roll-cladding of semi-finished strips (schematic)
  • Typical configurations of clad contact strips Figure 3
Typical configurations of clad contact strips
  • Contact materials
    Ag, Ag-alloys., Ag/Ni (SINIDUR), in special cases also Ag/CdO (DODURIT CdO), Ag/SnO2 (SISTADOX), Ag/ZnO (DODURIT ZnO)
  • Carrier materials
  • Dimensions Figure 4
Dimensions

When specifying the contact material layer thickness it is recommended to use the minimum required thickness.

  • Quality criteria and tolerances

Strength properties and dimensional tolerances of clad contact bi-metals are derived from the standards DIN EN 1652 and DIN EN 1654 for Cu alloys. When specifying the width of the contact material layer it is recommended to use the minimum required value. All dimensions should be specified originating from one strip edge.

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 Figure 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.

Toplay brazing with an inductive heating inline equipment (schematic)
  • Typical configurations of toplay contact profiles Figure 6
Typical configurations of toplay contact profiles
  • Contact materials
    Ag, AgNi 0,15 (ARGODUR), AgCu, AgCuNi (ARGODUR 27), Ag/Ni (SINIDUR),

Ag/CdO (DODURIT CdO), Ag/SnO2 (SISTADOX), Ag/ZnO (DODURIT ZnO)

  • Carrier materials
    Cu, CuZn, CuSn et al.
  • Quality criteria, dimensions and tolerances Figure 7
Quality criteria dimensions and tolerances

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

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 Figure 9. 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 Figure 8
Typical configurations of seam-welded contact strips
Seam-welding process (schematic)
  • Contact materials
    Au-Alloys, Pd-Alloys, Ag, AgNi 0,15 (ARGODUR), AgCu, AgCuNi (ARGODUR 27), Ag/Ni (SINIDUR), Ag/CdO (DODURIT CdO), Ag/SnO2 (SISTADOX), Ag/ZnO (DODURIT ZnO)
  • Carrier materials
    Cu, CuSn, CuZn, CuNiZn, CuBe et al.
  • Dimensions Figure 10
Contact Profiles Dimensions
  • Quality criteria and tolerances

Strength properties and dimensional tolerances of toplay profiles are derived from the standards 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 typically between 0.8 – 8.0 mm and 0.2 – 3.0 mm resp. Special configurations, often defined as miniature-profiles or even micro–profiles can have a width < 2.0 mm.

Miniature–profiles are mostly composed of a contact-bimetal material with the contact material being a precious metal alloy or composite material clad, welded or coated by electroplating or vacuum-deposition (sputtered) onto a weldable base material. Since these 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 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.

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 Figure 11
Typical configurations of multi-layer contact profiles
  • Contact materials
    Au-Alloys, Pd-Alloys, Ag-Alloys, Ag/Ni (SINIDUR), Ag/CdO (DODURIT CdO), Ag/SnO2 (SISTADOX), Ag/ZnO (DODURIT ZnO)
  • Carrier materials
    (weldable substrate material for multi-layer materials) Cu, Ni, CuNiFe, CuNiZn, CuSn, CuNiSn, NiCuFe
  • Brazing alloy
    L-Ag15P
  • Quality criteria
    Beause of the variety of configurations of contact profiles usually the quality issues are separately agreed upon between the manufacturer and the user.
  • Dimensions and tolerances Figure 12
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 ± 10%.

References

References