Production of Ca<sub>2</sub>AlNbO<sub>6</sub> Ceramics and Study of Their Stability in Crude Petroleum for the Conservation of Metallic Sensing Elements used in Petroleum Extraction

Abstract

In the present work a niobium based complex cubic perovskite oxide Ca<sub>2</sub>AlNbO<sub>6</sub> ceramic was produced, characterized and studied its stability in crude petroleum environment for inert ceramic embedding for temperature sensors used in petroleum extraction. Ca<sub>2</sub>AlNbO<sub>6</sub> 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 Å. Compacted discs of Ca<sub>2</sub>AlNbO<sub>6</sub> 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. Ca<sub>2</sub>AlNbO<sub>6</sub> 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

Production of Ba2AlNbO6 Ceramics and Study of their Stability in Crude Petroleum for the Conservation of Metallic Sensing Elements Used in Petroleum Extraction

“…X-ray diffraction patterns were recorded by using a Shimadzu, X-ray powder diffractometry, equipped with Cu -K α radiation (λ = 1.5406Å). After the structural analysis and identification of Ba 2 AlNbO 6 phase formation, calcined Ba 2 AlNbO 6 material were again subjected to grinding in high energy ball for 24 hours 16,17 for ceramic fine powder production and homogenization of particle size distribution.…”

“…As sintering is a thermo-dynamic process and due to furnace temperature limitation, it was necessary to increase the sintering time to achieve the sintered body. 17 Microstructural analysis of the sintered Ba 2 AlNbO 6 ceramics was carried out by scanning electron microscopy (model HITACHI TM3000), using backscattered electrons. To observe the microstructure, the samples were placed in a metal coating device to receive a 9 micronthin layer of gold, since they are not electrically conducting, to get SEM images.…”

“…17,22,23,24 sintered ceramics was studied by Vicker's micro-hardness testing, which gave a reasonablevalue of MHV = 56,43KgF/ mm 2 for ceramics sintered at 1150 0 C, which is satisfactory for encapsulation application of these ceramics. Results of X-ray diffractometry, microstructural and mechanical tests showed that Ba 2 AlNbO 6 ceramics submerged in crude petroleum did not suffer change at any stage of submersion.…”