Densification of lightweight aluminum borate ceramics by direct sintering of milled powders

HERNÁNDEZ, M.F.; SUÁREZ, G.; BAUDIN, C.; PENA CASTRO, P.; AGLIETTI, E.F.; RENDTORFF, N.M.

Journal of Asian Ceramic Societies

Taylor and Frances

Año: 2018 p. 1 - 10

Dense aluminum borate (Al18B4O33) materials were processed by simple milling-sintering ofaluminum borate powders obtained by reacting calcined alumina and fine boric acid attemperatures of around 600?800ºC. The effect of milling on the grain size and sinteringbehavior of the aluminum borate powders was also determined. Sintering began at around1000°C and was limited by the thermal decomposition (T > 1300 °C) of the borate in toalumina and boron oxide, which volatilize at this temperature. Sub-angular and mediumspherical sintered grain microstructures were developed. A hardness of 6 GPa and bulkdensity below 2.5 g/cm3 were achieved. The results are accomplished encouraging thestructural applications of borate materials.