Xrd Study Of The Silver / Ceramic Conductive Electrical Contact Materials

Different series of metalloid conductive ceramics are prepared through conventional technique of ceramic preparation, and then, as intensifier, been made into Ag-based conductive ceramic composited contact materials by the method of powder metallurgy. The structure of the conductive ceramic and Ag-based contact materials are studied.Synthesize series of La-Ni-O ceramic samples under different tempreature (1350℃,1400℃, 1450℃) and with different proportion of La and Ni (3:1, 2:1, 3:2, 1:1, 2:3, 1:2, 1:3) ,and then studied their phase structure through X-ray diffraction (XRD) and Scanning electricty Micrographic (SEM) . Analyze the powder diffraction data with the computer programm Jade5.0 and PDF data and then refine the data by Rietveld method in order to get precise micro-structure information of the samples. Discuss the relations between the phase structure of the ceramics and the stuff proportion and the prepare technics.With different quantum of Fe doped in above-mentioned La-Ni-O ceramic materials, the La-Fe-Ni-O solid solution materials' phase structure change. Analyze their powder diffraction data by XRD and Rietveld method and discuss the relations between the phase structure of the ceramics and the stuff proportion and the prepare technics.Put La₂NiO₄ and LaFe_0.25Ni_0.75O₃ ceramic respectively between two graphite electrodes and ablate them with high-power arc and then analyze the phase structure of the ceramics before and after corrosion to test the chemical stability of them. The research result shows that the La₂NiO₄ ceramic is single-phase material and has good chemical stability but LaFe_0.25Ni_0.75O₃ is multiphase and has bad chemical stability in atmosphere.To find a logical technics parameter we carry out a study on the powder metallurgy. The powders are ball milled for certain time respectively and then annealed an certain tempetature. The grain size differs obviously with the time of ball milling and it reaches the smallest value when been ball milled for 15～20 hours. The grain size also grows when annealed at certain temperature.