Different sintering routes for preparing alumina-yttrium aluminum garnet nanocomposites

作者：Palmero P^*; Stella C; Simone A; Esnouf C; Fantozzi G; Montanaro L

来源：Glass Physics and Chemistry, 2005, 31(4): 530-534.

DOI：10.1007/s10720-005-0094-9

Alumina-yttrium aluminum garnet (YAG) 50 vol % nanocomposite powders were prepared by a wet-chemical synthesis and characterized by simultaneous DTA-TG, XRD, and TEM analyses. Amorphous powders were preheated at four different temperatures (namely, 600, 800, 900, and 1215 degrees C) on the basis of the previous characterization, and the influence of this thermal treatment on sintering behavior, final microstructure, and density was investigated. The best-performing sample was that precalcined at 900 degrees C; however, dense bodies were just yielded by sintering at 1600 degrees C, resulting in a micronic/slightly submicronic microstructure. A preseeding step by a fast thermal treatment of the amorphous powder as well as a fast sintering procedure of green compacts, following some literature indications, were also performed as a comparison. Finally, the previously stated thermal pretreatment of the amorphous product was coupled to its extensive mechanical activation performed by wet planetary/ball milling. This procedure was strongly effective in lowering the densification temperature, so that fully dense alumina/YAG composites, with a mean grain size smaller than 200 nm, were obtained by sintering in the temperature range 1370-1420 degrees C.

• 出版日期2005-8