Main Articel: [[Switching Contacts| Switching Contacts]]
*'''Effects during switching operations'''
Fig. 6.7 Contact opening with arc formation (schematic)
*'''Influence of out-gasing from plastics'''
Fig. 6.9:
Histogram of the contact
resistance R of an electroplated K
palladium layer (3 μm) with and
without hard gold flash plating
(0.2 μm) after exposure with
different plastic materials
Fig. 6.10: Contact resistance with exposure to out-gasing from plastics as a function of numbers of
operations at 6 V ,100 mA: 1 Silicon containing plastic; 2 Plastics with strongly out-gasing DC
components; 3 Plastics with minimal out-gasing components
*'''Influence of corrosive gases on the contact resistance'''
Fig. 6.11: Distribution of cumulative frequency H of the contact resistance for solid contact rivets
after 10 days exposure in a three-component test environment with 400 ppb each of H<sub>2</sub>S, SO<sub>2</sub> and
NO<sub>2</sub> at 25°C, 75% RH; Contact force 10cN; Measuring parameters: ≤ 40 mV<sub>DC</sub>,10 mA; Probing
contact: Gold rivet
Fig. 6.8: Influences on contact areas in relays
*'''Contact Phenomena under the influence of arcing Matertia'''
*'''Material transfer'''
Fig. 6.12: Material transfer under DC load a) Cathode; b) Anode.
6 Material: AgNi0.15; Switching parameters: 12VDC, 3 A, 2x10 operations
*'''Arc erosion'''
Fig. 6.13 Arc erosion of a Ag/SnO<sub>2</sub> contact pair after extreme arcing conditions
a) Overall view; b) Partial detail view
*'''Contact welding'''
Fig. 6.14: Micro structure of a welded contact pair (Ag/SnO<sub>2</sub> 88/12 - Ag/CdO88/12)
after extremely high current load. a) Ag/SnO<sub>2</sub> 88/12; b) Ag/CdO88/12
===6.4.5 Physical Effects in Sliding and Connector Contacts===