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 rmWcm 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

2.3.2 Contacts

© H. Föll (Advanced Materials B, part 1 - script)