The Lafe <sub> X </ Sub> Ni <sub> 1-x </ Sub> The O <sub> 3 </ Sub> Ceramics And Composite Electrical Contact Materials, Physical Properties,

The series of ceramics LaFe_xNi_1-xO₃ were prepared through conventional technique of ceramic preparation. LaFe_0.25Ni_0.75O₃ was mixed with silver powders to form electrical composite contact materials. Fundamental physical and chemical characteristics of ceramics and the Ag-based contact materials were discussed.Mix conductive ceramics and metal or metal-oxide which acts as the third phase into silver matrix in different proportions, and then discuss its effect on the arc corrosion .mass transfer, electrics and arc blazing time performances of the contacts.By means of XRD, we studied the phase structure of LaFe_0.25Ni_0.75O₃ ceramics . we found LaFe_0.25Ni_0.75O₃ was a composite ceramic made up of several phases,and there was different phase in LaFe_0.25Ni_0.75O₃ ceramic with different x. So by controlling the material ratio and the technique of sintering, we can get ceramics with confirmed proportion of phase structure.The infrared absorption spectra of LaFe_xNi_1-xO₃ were measured by FT-IR-NEXUS-670.We found the IR spectra was according with the XRD.The IR spectra changed with the different x value.The LaFe_xNi_1-xO₃ thermal coefficient of expansion was measured by PCY model high temperature horizontal expansion apparatus . The thermal coefficient of expansion increases rapidly with the increasing temperature before 400℃ whereas increases slowly after 400℃. With the increasing of the x value and the temperature of sintering, the thermal coefficient of expansion decreases.The conductive ceramic LaFe_0.25Ni_0.75O₃ has particular microstructure of network distribution and samdwich. With high melting point and little resistivity, it becomes a kind of semiconductor material with perfect conductivity. Its phase structure wouldn't take any change after high-power arc corrosion which proved its good chemical stability. The electrical contact materials which were mixed up with this kind of ceramics and silver had low resistivity, nice corrosion-resisting...