Difference between revisions of "Physical Effects in Sliding and Connector Contacts"

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(Physical Effects in Sliding and Connector Contacts)
(Physical Effects in Sliding and Connector Contacts)
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===<!--6.4.5-->Physical Effects in Sliding and Connector Contacts===
 
===<!--6.4.5-->Physical Effects in Sliding and Connector Contacts===
  
'''Mechanical wear of sliding contacts'''
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*'''Mechanical wear of sliding contacts'''
  
 
<table class="twocolortable" style="text-align: left; font-size:12px;width:40%">
 
<table class="twocolortable" style="text-align: left; font-size:12px;width:40%">
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'''Contact behavior of connectors'''
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*'''Contact behavior of connectors'''
  
 
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<div class="multiple-images">
[[File:Coefficient of frictional wear for the wear loss of sliding contacts Silver Silver.jpg|left|thumb|Figure 1: Coefficient of frictional wear for the wear loss of sliding contacts Silver/Silver and hard gold/hard gold as a function of the contact force]]
 
 
 
<figure id="fig:Contact resistance Rk as a function of the contact force Fk">
 
<figure id="fig:Contact resistance Rk as a function of the contact force Fk">
[[File:Contact resistance Rk as a function of the contact force Fk.jpg|left|thumb|Figure 2: Contact resistance R<sub>k</sub> as a function of the contact force F<sub>k</sub> for different surface coating materials. Measured against a spherical gold probe; I = 10 mA, U < 20 mV]]
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[[File:Contact resistance Rk as a function of the contact force Fk.jpg|left|thumb|Figure 1: Contact resistance R<sub>k</sub> as a function of the contact force F<sub>k</sub> for different surface coating materials. Measured against a spherical gold probe; I = 10 mA, U < 20 mV]]
 
</figure>
 
</figure>
  
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[[File:Coefficient of frictional wear for the wear loss of sliding contacts Silver Silver.jpg|left|thumb|Figure 2: Coefficient of frictional wear for the wear loss of sliding contacts Silver/Silver and hard gold/hard gold as a function of the contact force]]
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<div class="multiple-images">
 
<figure id="fig:Contact resistance Rk as a function of the fretting wear cycles">
 
<figure id="fig:Contact resistance Rk as a function of the fretting wear cycles">
 
[[File:Contact resistance Rk as a function of the fretting wear cycles.jpg|left|thumb|Figure 3: Contact resistance R<sub>k</sub> as a function of the fretting wear cycles for different surface coating materials]]
 
[[File:Contact resistance Rk as a function of the fretting wear cycles.jpg|left|thumb|Figure 3: Contact resistance R<sub>k</sub> as a function of the fretting wear cycles for different surface coating materials]]

Revision as of 09:18, 4 January 2023

Physical Effects in Sliding and Connector Contacts

  • Mechanical wear of sliding contacts
dV/dx = k x FK /3 HW
dV/dx Wear volume in mm3 per slide path length in mm
k Coefficient of frictional wear
HW Hardness of the softer material
(Brinell or Vickers units)
FK Contact force in cN
Wear coefficient k during material transfer
Silver – Silver 120 x 10-4
Platinum – Platinum 400 x 10-4
Silver – Platinum 1.3 x 10-4
Coefficient of fractional wear k during wear loss
Silver – silver 8 x 10-4
Gold – gold 9 x 10-4
Platinum – platinum 40 x 10-4
Silver – gold 9 x 10-4
Silver – platinum 5 x 10-4


  • Contact behavior of connectors
Figure 1: Contact resistance Rk as a function of the contact force Fk for different surface coating materials. Measured against a spherical gold probe; I = 10 mA, U < 20 mV
Figure 2: Coefficient of frictional wear for the wear loss of sliding contacts Silver/Silver and hard gold/hard gold as a function of the contact force


Figure 3: Contact resistance Rk as a function of the fretting wear cycles for different surface coating materials


Table 1: Surface Coating Materials for Connectors
Manufacturing method Coating materials Intermediate layer Hardness HV Frictional factor
Electroplating Tin
Nickel
Nickel-phosphorus (NiP 6 - 15)
Silver
Hard gold (< 0.3 wt% Ni or Co)
Palladium with Au- flash (<0,2μm)
Palladium-nickel with Au-flash (<0.2μm)
For brass: Copper or Nickel



Nickel, Nickel-phosphorus
Nickel
Nickel
50 - 90
300 - 600
500 - 1100
70 - 100
100 - 200
250 - 300
300 - 400
0.5 - 1


0.5 - 0.8
0.2 - 0.5
0.2 - 0.5
0.2 - 0.5
Cladding Gold-nickel (AuNi 5 -10)
Silber-palladium (AgPd 10 - 30)
Nickel
Nickel
160 - 200
120 - 170
0.2 - 0.5
0.2 - 0.5
Hot-dipped tinning Tin Inter-metallic compound(1) Tin–copper 400 - 500
(1) is formed during hot tinning process

References

References