Erosion resistance of composite Ag'MCaF sub(2) contacts

The erosion resistance of composite Ag'MCaF sub(2) contacts in the communitation of constant currents I=1-10 A was studied. With the aid of metallographic analysis it was shown that in comparison with cast silver contacts, composite contacts even at I=1 A show a stronger tendency to change the direction of mass transport, which increases with increase of the current to I less than or equal to 4 A. In this range of commutation currents there is a small loss of material, accompanied by the removal of a considerable part of Ag'MCaF sub(2) particles from the working zone to the periphery of the contacts, which promotes their improvement. The laws revealed in the work allowed us to recommend the composite Ag'MCaF sub(2) contacts for use in relay technology. Tests in microswitches confirmed the high erosion resistance of composite contacts in the range I=1-3 A.