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vol.45 número291Mullite synthesised from aluminium hydroxide and silica from rice hullInvestigation of the electrochromic behavior of Nb2O5 thin films using chemometric method índice de autoresíndice de materiabúsqueda de artículos
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Cerâmica

versión impresa ISSN 0366-6913

Resumen

QUARANTA, N. E.  y  BENAVIDEZ, E. R.. Aluminosilicates compacts by alkoxide route: influence of Ba addition. Cerâmica [online]. 1999, vol.45, n.291, pp. 38-40. ISSN 0366-6913.  http://dx.doi.org/10.1590/S0366-69131999000100007.

The sol-gel route was employed to obtain three different powders with the stoichiometric composition corresponding to mullite (3 Al2O3.2SiO2): (i) commercial alumina and silica from sol-gel, (ii) alumina and silica by alkoxide partial hydrolysis, (iii) alumina and silica by alkoxide simultaneous hydrolysis. Tetraethylorthosilicate (TEOS) and aluminium tri-sec-butoxide were used as alkoxide precursor. Moreover, 5 wt% of barium, incorporated to precursor solutions as Ba-acetilacetonate, was used as additive to study its influence on densification and mullite phase formation. The precursor powders were pressed uniaxially to form green compacts, after that all samples were heated to 1350 °C for 2 hours to obtain densified pellets. X-ray diffration patterns of powders, obtained by milling of sintering compacts, showed important differences. In barium doped samples a higher grade of densification and a greater glassy phase formation were observed.

Palabras llave : sol-gel; barium; alkoxides; aluminosilicates.

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