Electrical Contact materials

Electrical contacts are subjected to extreme mechanical and thermal stresses during operation. For fractions of a second, temperatures rise to several thousand degrees as a result of the arcing. Only Tungsten Copper materials will stand these high temperature & aberration.
Tungsten Copper material has good resistance to arc erosion, mechanical wear, contact welding and good conductivity. They are usually selected for oil, gas, air or vacuum, devices. The contact surfaces will oxidize when switched in air. These press-sinter-infiltrate materials should only be considered for arcing surfaces in air when used as arcing tips, arc plates and arc runners. When switching with moderate contact arcing, the Tungsten Copper with a high copper content may give the lowest erosion. As arcing severity increases, the Tungsten Copper with the higher refractory content withstand arc erosion better. Tungsten Coppers are also used as arcing edges of selector switchblades in transformer tap changers.