Difference between revisions of "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)
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*'''Contact behavior of connectors'''
 
*'''Contact behavior of connectors'''
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<xr id="fig:fig6.16"/> Fig. 6.16: 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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<xr id="fig:fig6.17"/> Fig. 6.17: Contact resistance R<sub>k</sub> as a function of the fretting wear cycles for different surface coating materials
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<div class="multiple-images">
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<figure id="fig:fig6.16">
 
[[File:Contact resistance Rk as a function of the contact force Fk.jpg|right|thumb|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]]
 
[[File:Contact resistance Rk as a function of the contact force Fk.jpg|right|thumb|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]]
Fig. 6.16: Contact resistance R as a function k
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</figure>
of the contact force F for different surface k
 
coating materials. Measured against a
 
spherical gold probe; I = 10 mA, U < 20 mV
 
  
 +
<div class="multiple-images">
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<figure id="fig:fig6.17">
 
[[File:Contact resistance Rk as a function of the fretting wear cycles.jpg|right|thumb|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|right|thumb|Contact resistance R<sub>k</sub> as a function of the fretting wear cycles for different surface coating materials]]
Fig. 6.17: Contact resistance R as a function k
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</figure>
of the fretting wear cycles for different surface
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</div>
coating materials
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<div class="clear"></div>
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'''Tab.6.4: Surface Coating Materials for Connectors'''
 
'''Tab.6.4: Surface Coating Materials for Connectors'''

Revision as of 16:21, 1 April 2014

6.4.5 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


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

Fig. 6.15: 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

  • Contact behavior of connectors

Figure 1 Fig. 6.16: 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 Fig. 6.17: Contact resistance Rk as a function of the fretting wear cycles for different surface coating materials

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


Tab.6.4: 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

References

References