Development of Copper-Chromium Clectrical Contact Materials by Powder Forging

The electrical contacts form an integral part of circuit interrupters for which the desirable properties of contact materials are high mechanical strength, high electrical and thermal conductivity, high wear and weld resistance. Despite of different manufacturing techniques like electro-slag crucible melting, vacuum arc smelting, vacuum continuous smelting etc. , the Powder Forging being a solid state process and having high densification factor is an efficient method for the production of electrical contact materials. In the present study Cu-Cr30 wt. % alloys are prepared from elemental powders by sinter-forging. Nb is also added in varying quantities to improve the electrical and mechanical properties and the forging temperature is also varied. The variation in contact material properties due to these changes are tabulated and compared.