# Some Properties of Ag Based Contact Materials

| The following table lists just a few Ag based alloys that are obtained by a sintering process for specific contact uses
|  | The melting point is always around 960 oC
Alloy | r [mWcm] | Brinell Hardness [kp/mm2] | Uses
Ag (60 .... 90) % Ni (40 ... 10) % | 2,8...2,0 | 50 ... 130 | Low Voltage circuit breakers
Ag 88% CdO 12% | 2,4 | 60 ... 70 | Circuit breakers
Ag 95% SnO2 5% | 2,5 | 50 ..60 | High load relays
Ag 98 % C 2 % | 2,5 | 35 ... 45 | Welding resistant contacts
Ag (10 ... 30) % W (90 ... 70) % | 5,0 ... 4,0 | 105 ... 230 | Low voltage high power switches

| The next table lists just a few Ag based alloys that are obtained by melting the constituents
|  | The melting point varies from (800 - 1030) oC
Alloy | r mWcm | Brinell Hardness (kp/mm2) | Uses
Ag 85 % Cd 15 % | 4,8 | 40...78 | Welding resistant DC contacts
Ag (72 ...97) % Cu (28...3) % | 1,8 ... 2,1 | 40...140 | Heavy duty relay contacts
Ag 95% Ni 5% | 1,9 | 50 | Contacts in communication technology
Ag (70..50) % Pd (30...50) % | 15,6...32 | 70...190 | Contacts in communication technology
Ag 20 % Au 80 % | 10 | 37...90 | Fine contacts
Cu ca. 95 % Co (...2,5) % Be (1..3) % | 3,5...10 | 100...400 | Brushes, pantographs

1) S = Siemens = 1/W

With frame

2.2.2 Contacts

© H. Föll (Electronic Materials - Script)