Silver Copper Oxide Electrical Contact Materials Performance

The differences of the microstructure and properties of the sintered body, between the fabrication method of powder metallurgy and reactive synthesis for AgCuO materials, were investigated in present thesis. With the increase of copper oxide content in silver matrix, the density and the electric conductivity of AgCuO materials tended to decrease. While in the same copper oxide content, the electric conductivity of AgCuO materials fabricated by reactive synthesis was better than it by powder metallurgy, which was concerned with the regular net structure existing in the former materials. The electric conductivity of the latter was not better, owing to the disordered microstructure and the copper oxide particles assembling in matrix. After the sintered body were repressed and re-sintered, the change of materials' microstructure resulted in the density and the electric conductivity of AgCuO.The wires of AgCuO were obtained after the re-sintered bodies were hot extruded and cold drawn. The electric conductivity of the wires increased obviously because of theirs special fibrous microstructure. The resistivity of the wires fabricated by reactive synthesis was less than that fabricated by powder metallurgy. In the process of the tensile experiments of the wires, the change trend of the tensile strength with the deformation of the wires fabricated by reactive synthesis was consistent with the change trend of the wires fabricated by powder metallurgy. But the abnormality of the tensile strength appeared when the deformation of AgCuO(wt.12%) materials made by powder metallurgy was 35%. It was concluded that the plasticity and the working performance of the wires made by reactive synthesis was better according to the curves of the elongation and the deformation.The preparation technology was influence on the service life and the electric wear of AgCuO. In the Direct Current load, the service life of AgCuO(wt.10%) fabricated by reactive synthesis was 1.8 times than the service life of AgCuO(wt.10%) fabricated by powder metallurgy, the electric wear of the former was 0.6 times than the electric wear of the latter. In the Direct Current load, the service life of AgCuO(wt.12%) fabricated by reactive synthesis was 2.2 times than the service life of AgCuO(wt.12%) fabricated by powder metallurgy, the electricwear of the former was the same as the electric wear of the latter. In the Alternating Current load, the service life of AgCuO(wt.12%) fabricated by reactive synthesis was 3.3 times than the service life of AgCuO(wt.12%) fabricated by powder metallurgy, the electric wear of the former was 0.1 times than the electric wear the latter.In this paper, AgCuO electrical contact materials fabricated by reactive synthesis and by powder metallurgy were systemically studied in microstructure, properties and contents. AgCuO materials with different copper oxide content were successfully fabricated. By computation of thermodynamics and dynamics, the reactive driving force(G), the oxygen partial pressure and the diffusion of [0] in the alloy were analyzed. And it was proved in the theory that AgCuO materials fabricated by reactive synthesis were feasible.Reactive synthesis technology was a new method of fabrication by AgCuO. Because of its advanced production way, the fabrication method of reactive synthesis presented the great advantage in the aspect of structure and properties of materials. So reactive synthesis can become the new technique of preparation.