Main Articel: [[Physical Effects in Sliding and Connector Contacts| Physical Effects in Sliding and Connector Contacts]]
*'''Mechanical wear of sliding contacts'''
dV/dx = k x FK /3 HW
3 dV/dx Wear volume in mm 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
-4 Silver – Silver 120 x 10
-4 Platinum – Platinum 400 x 10
-4 Silver – Platinum 1.3 x 10
Coefficient of fractional wear k during wear loss
-4 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
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'''
Fig. 6.16: Contact resistance R as a function k
of the contact force F for different surface k
coating materials. Measured against a
spherical gold probe; I = 10 mA, U < 20 mV
Fig. 6.17: Contact resistance R as a function k
of the fretting wear cycles for different surface
coating materials
Tab.6.4: Surface Coating Materials for Connectors
===6.4.6 General Rules for Dimensioning of Contacts===