Production of Casub2/subAlNbOsub6/subCeramics and Study of Their Stability in Crude Petroleum for the Conservation of Metallic Sensing Elements used in Petroleum Extraction

摘要

In the present work a niobium based complex cubic perovskite oxide Ca2AlNbO6 ceramic was produced, characterized and studied its stability in crude petroleum environment for inert ceramic embedding for temperature sensors used in petroleum extraction. Ca2AlNbO6 ceramic powder was prepared through thermo-mechanical processing. Structural characteristics of calcined material was investigated by powder X-ray diffarctometry, which presented a single phase complex cubic perovskite structure with lattice parameter a = 7.6599 ?. Compacted discs of Ca2AlNbO6 ceramics were sintered in the temperature range 1250°C - 1350°C during 24 hours in ambient atmosphere. Microstructure of the sintered ceramics was studied by scanning electron microscopy and mechanical behavior was studied by Vicker’s microhardness testing. Ca2AlNbO6 ceramics sintered at 1350°C presented best results in terms of microstructural homogeneity and mechanical hardness. Therefore these sintered ceramics were submerged in crude petroleum for 60 days. Ceramics were taken out from the petroleum periodically and subjected to structural, microstructural and mechanical characterizations. Results showed that ceramics submerged in crude petroleum did not suffer any change at any stage of submersion. These characteristics make this material suitable for inert ceramic embedding for sensors used in petroleum extraction.