It is presented a study about the effects of the sintering atmosphere (vacuum, hydrogen) on the final resulted properties of the electric contacts with W-Cu-Ni chemical composition. The use of alloys containing an amount of tungsten (over 65%) has increased during last years because of their unique combination of properties. These properties are a result of the chemical composition of the alloy on one hand, and a specific microstructure obtained during liquid phase sintering on the other hand. As a result it was compulsory to study the parameters that influence the densification process and the sintered properties, depending on the sintering temperature and the copper-infiltrating atmosphere. Therefore, it has been studied the influence of these parameters on the density, hardness and microstructures changes for the composites with 78%W-2%Ni-20%Cu, (% wt). The better results were obtained for the value of 1350 ~0C for the copper infiltration temperature, for both sintered atmosphere.
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