TECHNICAL DATA SHEETS |
TECHNICAL DATA
SHEET
SILVER METAL OXIDE CONTACT MATERIALS
OVERVIEW
Silver metal oxide contact materials are used widely to serve low
and medium power applications. Relays, contactors, switches and
low voltage circuit breakers all employ silver metal oxide
contact materials. Silver cadmium oxide and silver tin oxide are
utilized due to their relatively high and stable conductivity,
their anti-welding and their arc quenching properties. These
materials are produced through powder metallurgy techniques as
well as traditional wrought metallurgy techniques. The
differences in the two processes entail differences principally
in the distribution of the metal oxide component inside the
silver matrix. The metal oxide distribution and particle size
significantly affects contact performance.
AVAILABILITY
Silver-cadmium oxide and silver-tin oxide are produced in sheet
and wire products. Consequently, they are available as discrete
contacts, contact rivets, and in clad contacts and contact tapes
and in the complete range of clad strips and their by-products.
When welding or brazing attaching either of these materials it is
typical to employ a pure silver backing. This assists in the
bonding of the contact to the adjacent metal substrate.
MATERIALS |
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Composition |
Hardness |
Density |
Conductivity |
(weight %) |
(R'well) |
(g/cc) |
(IAS %) |
Silver-Cadmium Oxide |
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SCDO10 Ag90/CdO10 |
F 45* |
10.1 |
75 |
SCDO15 Ag85/CdO15 |
F 50* |
10.01 |
55 |
WCDO1-10 Ag90/CdO10 |
F 45* |
10.15 |
82 |
WCdO1-15 Ag85/CdO15 |
F 55* |
10.1 |
70 |
WCDO2-10 Ag90/CdO10 |
F 45* |
10.2 |
70 |
WCDO2-15 Ag85/CdO15 |
F 50* |
10.1 |
60 |
Silver-Tin Oxide |
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WSNO1-10 Ag90/SnO10 |
F 55* |
9.8 |
75 |
WSNO1-12 Ag88/SnO12 |
F 60* |
9.7 |
70 |
Note
The asterisk (*) indicates the fully annealed condition. The
compositions listed are generally considered the industry
standards. The values listed above represent the typical average
properties of the materials. Modifications to meet special
applications may be possible.