Sintered electrical contacts for vacuum current interruption

The paper presents the experiments of elaboration copper-chromium electrical contacts, with 40-75 % copper content, manufactured by powder metallurgy techniques: infiltration with copper of a chromium frame and solid state sintering of chromium and copper powder mixture. The influence of technological parameters - powder granulometry, compacting pressure, sintering and infiltration temperature - on the physical (density, hardness) and microstructural characteristics of contacts are presented. The elaborated contacts were tested in order to determine their properties in the case of high currents interruption.