Tungsten silver electrical contacts which are composited by 60%Mo40%Ag is used for arcing contacts in both air and oil circuit breakers. It has good arc erosion characteristics. Low contact resistance permits good transfer of current from current carrying to the arcing contacts. Its low contact resistance plus resistance to welding make it a suitable material for high inrush currents at low voltage. It is also used in heavy duty truck starting contactors where it operates against a copper shorting contact.
Tungsten silver electrical contacts which are composited by 50%Mo50%Ag is used for contacts that both carry and interrupt current. It is used in low and intermediate rated household and industrial air circuit breakers. It is also used as arcing contacts in oil circuit breakers, as well as shoe contacts in transformer tap changers.
Tungsten silver electrical contacts which are composited by 65%Mo35%Ag is the most economical of the silver infiltrated materials in this group. It is used for low rated circuit breakers.
Tungsten silver electrical contacts which are composited by 65%Mo35%Ag are made by the press-sinter-repress method. Its primary advantage is the ease of manufacturing into thin and small shapes. It can be directly attached to a blank without special finishing operations and provides a cap with good resistance to erosion and good current carrying capabilities. Use in automotive truck starters is a typical application.
|Composition% by Volume
||Electrical Conductivity % IACS
||Rockwell Hardness B
PSI = Press Sinter Infiltrate PSR = Press Sinter Repress