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

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(Physical Effects in Sliding and Connector Contacts)
(6.4.5 Physical Effects in Sliding and Connector Contacts)
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===<!--6.4.5-->Physical Effects in Sliding and Connector Contacts===
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===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%">
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{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
<tr>
+
|-
<td>dV/dx = k x F<sub>K</sub> /3 H<sub>W</sub></td>
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|dV/dx = k x F<sub>K</sub> /3 H<sub>W</sub>
</tr><tr>   
+
|-
<td>dV/dx    Wear volume in mm<sup>3</sup> per slide path length in mm</td>
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|dV/dx    Wear volume in mm<sup>3</sup> per slide path length in mm
</tr><tr>
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|-
<td>k        Coefficient of frictional wear</td>
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|k        Coefficient of frictional wear
</tr><tr>
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|-
<td>H<sub>W</sub>        Hardness of the softer material <br />(Brinell or Vickers units)</td>
+
|H<sub>W</sub>        Hardness of the softer material <br />(Brinell or Vickers units)
</tr><tr>
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|-
<td>F<sub>K</sub>        Contact force in cN</td>
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|F<sub>K</sub>        Contact force in cN
</tr><tr>
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|-
<td>'''Wear coefficient k during material transfer'''</td>
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|'''Wear coefficient k during material transfer'''
</tr><tr>
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|-
<td>Silver – Silver 120 x 10<sup>-4</sup></td>
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|Silver – Silver 120 x 10<sup>-4</sup>
</tr><tr>
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|-
<td>Platinum – Platinum 400 x 10<sup>-4</sup></td>
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|Platinum – Platinum 400 x 10<sup>-4</sup>
</tr><tr>
+
|-
<td>Silver – Platinum 1.3 x 10<sup>-4</sup></td>
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|Silver – Platinum 1.3 x 10<sup>-4</sup>
</tr><tr>
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|-
<td>'''Coefficient of fractional wear k during wear loss'''</td>
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|'''Coefficient of fractional wear k during wear loss'''
</tr><tr>
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|-
<td>Silver – silver 8 x 10<sup>-4</sup></td>
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|Silver – silver 8 x 10<sup>-4</sup>
</tr><tr>
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|-
<td>Gold – gold 9 x 10<sup>-4</sup></td>
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|Gold – gold 9 x 10<sup>-4</sup>
</tr><tr>
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|-
<td>Platinum – platinum 40 x 10<sup>-4</sup></td>
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|Platinum – platinum 40 x 10<sup>-4</sup>
</tr><tr>
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|-
<td>Silver – gold 9 x 10<sup>-4</sup></td>
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|Silver – gold 9 x 10<sup>-4</sup>
</tr><tr>
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|-
<td>Silver – platinum 5 x 10<sup>-4</sup></td>
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|Silver – platinum 5 x 10<sup>-4</sup>
</tr>
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|}
</table>
+
 
 +
 
 +
 
 +
[[File:Coefficient of frictional wear for the wear loss of sliding contacts Silver Silver.jpg|right|thumb|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'''
 +
<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
  
'''Contact behavior of connectors'''
+
<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
  
 
<div class="multiple-images">
 
<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: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]]
<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]]
 
 
</figure>
 
</figure>
  
<figure id="fig:Contact resistance Rk as a function of the fretting wear cycles">
+
<div class="multiple-images">
[[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]]
+
<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]]
 
</figure>
 
</figure>
 
</div>
 
</div>
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<figtable id="tab:Surface Coating Materials for Connectors">
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'''Tab.6.4: Surface Coating Materials for Connectors'''
<caption>'''<!--Tab.6.4:-->Surface Coating Materials for Connectors'''</caption>
 
  
 
{| class="twocolortable" style="text-align: left; font-size: 12px"
 
{| class="twocolortable" style="text-align: left; font-size: 12px"
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|
 
|
 
|}
 
|}
<div id="text-reference">(1) is formed during hot tinning process</div>
+
<div id="text-reference">(1)is formed during hot tinning process</div>
</figtable>
 
 
 
<div class="clear"></div>
 
  
 
==References==
 
==References==
 
[[Application Tables and Guideline Data for Use of Electrical Contact Design#References|References]]
 
[[Application Tables and Guideline Data for Use of Electrical Contact Design#References|References]]
 
[[de:Physikalische_Effekte_bei_Gleit-_und_Steckkontakten]]
 

Revision as of 09:59, 2 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
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