Low Voltage Electrical Contacts

Silver Tin Oxide Contact

Silver Tin Oxide Contact

Silver tin Oxide (AgSnO2) based contacts since their introduction are looked upon as potential replacement for AgCdO. The AgSnO2 contacts have seen continued improvisation, with respect to their applicability and performance, by enhancement in their fine microstructure.

AgSnO2 based contacts are increasingly dominating the market for medium and high current contact relays because of their low arc erosion. Besides the base oxide SnO2 embedded in the Ag matrix, these materials may or may- not contain additives like Bi2O3, CuO, In2O3, WO3 and MoO3 in a combination of varying amounts not exceeding 2%. The AgSnO2 based contacts are manufactured by powder metallurgy (powder blending, compaction and sintering) followed by extrusion/ drawing/ rolling to the final dimensions.

Modison offers a range of AgSnO2 products in various forms (profiles, wires, strips, etc.) manufactured by powder metallurgy. The profiles or strips can be provided with 10% - 20% fine silver layer for easy brazing. The material quality meets the prevailing standard international norms.

Wire (Magnification 100X)

Strip (Magnification 100X)

Technical Specifications

Composition (wt %) Ag (89-90), SnO2 (8-9) Ag (87-88), SnO2 (10-11) Ag (85-87), SnO2 (12-13) Same as doped
Additives Bi2O3, Cu Bi2O3, Cu Bi2O3, Cu Ub-doped
Density (g/cc) 9.9 9.8 9.7 Same as doped
Electical Conductivity (% IACS) 78-82 75-80 74 Same as doped
Hardness (HV) 65-100 65-100 70-115 Same as doped
Tensile strength (N/mm2) 280-320 280-320 - Same as doped