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

FLORENCIA HERNANDEZ; GUSTAVO SUAREZ; CARMEN BAUDIN; PILAR PENA; ESTEBAN F. AGLIETTI; NICOLAS M. RENDTORFF

Journal of Asian Ceramic Societies

Taylos and Francis Online

Año: 2018

2187-0764

Dense aluminum borate (Al18B4O33) materials were processed by a simple milling-sintering route of aluminum borate powders obtained by reaction of calcined alumina and fine boric acid at temperatures around 600- 800ºC.The effect of milling on the grain size of the powders and sintering behavior of aluminum borate powders was also determined. Sintering started around 1000°C and is limited by the thermal decomposition (T> 1300 °C) of the borate to alumina and boron oxide, which at this temperature volatilize. Sub angular and medium spherical sintered grain microstructure was developed. 6 GPa hardness and bulk density below 2.5 g/cm3 were achieved. The accomplished results encourage the structural application of the borate materials.