Scope
This information refers to silver based contact material with tungsten as the second main component manufactured by inifitration of molten silver into a porous tungsten preform.
DESIGNATION OF
STANDARD COMPOSITIONS
The tungsten content is designated in
weight percent. It can be adjusted between
40 to 8o %
Applications
- circuit breakers
- earth leakage breakers
- miniature circuit breakers
- power Line relays
CHARACTERISTICS
- lowest arc erosion of all contact materials
- low electrical conductivity
- high contact resistance by formation of tungsten oxides as well as silver-tungsten
- poor arc migration properties
- very hard
MICROSTRUCTURE
A higher amount of tungsten leads to a more regulat’ distribution of the components.
Physical Properties
| Material |
AgW40 |
AgW50 |
AgW60 |
AgW65 |
AgW70 |
| Density [g/cm3] |
12.5 |
13.2 |
14.0 |
14.4 |
14.9 |
| Electrical Conductivity [m/(Ω.mm2)] |
41 |
38 |
34 |
32 |
31 |
| Hardness Soft [HRB] |
50 |
80 |
85 |
90 |
90 |