Bimetal Rivets

Silver and pure silver possess very high electric and thermal conductivity. Low
and stable contact resistance and good processing and welding performance. 
Because of a little nickel added into silver, pure silver has higher intensity and
thermal-resistance performance than silver under same contact resistance. 
Therefore its fusion resistance and arc burning resistance are better than that 
of silver. Under the same application condition, pure silver can take the place of
silver AgNi material with 10-40% of high melting-point metal nickel has high 
electric conductivity, low contact resistance and little burning loss. This material
has little transfer when connecting and breaking direct current. To be widely 
used in AC and DC low-voltage devices, such as relays, instruction switches, 
can switches, breaker, assisting contactors. Instrument switches, optical 
control switches, temperature controller and washing machine timers, etc.

AgZnO has higher thermal stability than AgCdO, therefore, has better fusion 
resistance and arc burning resistance. But its contact resistance is high. Since
AgZnO is innoxiously and has no pollution to the environment. It is one of the 
ideal materials to substitute AgCdO at present.

AgCdO is the most used contact material at present. CdO obviously increased 
the fusion resistance or cohesive resistance of the contacts at the moment of 
getting through big current. The sublimation of CdO cools the contact surface. 
Lowers the arc energy and extinguishes the arc. Therefore AgCdO can meet 
the main requirements of low-voltage apparatus to contacts. Such as arc 
burning resistance at big-current switching-on, low and stable contact 
resistance under various loads and good arc extinguishing performance. Since 
Cd pollutes the environment. Other materials are substituting it. To be used to 
low-0voltage apparatus with medium or high load, typically use to micro 
switches, relays, protection switches, contactors and auto-switches, etc.

AgSnO2 and AgSnO2 In2O3 are the ideal environment-protecting materials for substituting AgCdO. Since SnO2 has better thermal stability and higher hardness 
than CdO, AgSbO2 ABD AgSnO2 In2O3 is higher and it is more difficult to 
processing these two materials. To be used to substitute AgCdO material in the 
low-voltage apparatus field, such as breakers, contactors and relays, etc. 
Especially being used to DC apparatus for automobiles, such contactors, starters
and photo switches. 

The AgC contact material containing 3-5% graphite bears the highest fusion 
resistance. low contact resistance and small temperature rise in switching on 
short circuit current. and is self-lubricated when being used as a sliding contact.
The AgC contact material manufactured by sintering and extrusion process not 
only has high density, but also has a lower burning loss rate under arc action 
due to the fiber-oriented graphite particles. it is usually used with Cu or AgNi
in pairs.