Preparation of MgAl2O4 nanopowders via hydrolysis of double magnesium-aluminum isopropoxide

2^nd International Conference and Expo on Ceramics & Composite Materials

July 25-26, 2016 Berlin, Germany

Anastasia V Novikova, Stanislav S Balabanov, Alexander V Belyaev, Evgeny M Gavrishchuk, Victor V Drobotenko and Dmitry A Permin

G G Devyatykh Institute of Chemistry of High-Purity Substances RAS, Russia
N I Lobachevsky State University of Nizhny Novgorod, Russia

Posters & Accepted Abstracts: J Material Sci Eng

Abstract :

Magnesium aluminate spinel ceramics is promising optical material for industrial and military applications due to its high hardness, melting point, thermal conductivity and high optical transmission in the ultraviolet, visible, and infrared spectral ranges. The properties of such ceramics are significantly determined by the characteristics of the starting powder: its stoichiometry, morphology and crystallite size. This work is devoted to the development of MgAl2O4 nanopowders fabrication technique via alkoxotechnology using double magnesium aluminum isopropoxide (MgAl2(OPri)8) as the precursor. MgAl2(OPri)8 was synthesized by interaction of activated magnesium-aluminum alloy with isopropyl alcohol. Since the precursor is a volatile compound, vacuum distillation method was successfully used for its purification and the possibility of high pure powders synthesis from starting technical pure grade materials were demonstrated. According to ICP-AES analysis the main impurities in synthesized MgAl2(OPri)8 are Si (9 ppm), Fe (0.39 ppm), Na (0.35 ppm), Zn (0.36 ppm). The content of the rest elements is below the detection limit. The hydrolysis of MgAl2(OPri)8 was performed by azeotropic mixture isopropyl alcohol â�� water (ratio 88:12 vol. %) with equimolar ratio 1:8. Magnesium aluminate spinel powders were obtained by calcining the hydrolysis products at 900�°C. The powder particles are spherical with the average size of 30-50 nm and aggregated into soft agglomerates up to 50 �¼m in size. The resulting powders were used to sinter MgAl2O4 ceramic by hot pressing at a temperature of 1600�°C and pressure of 50 MPa in graphite dies. Optical transmission of obtained transparent samples is more than 80%.

Biography :

Email: anastasia93novikova@yandex.ru