SYNTHESIS AND CHARACTERIZATION OF CORDIERITE FROM ACETYLACETONATE ALKOXIDE PRECURSORS

Syntheses of ultrafine glass powders in the MgO-Al2O3-SiO2 ternary oxi de system were effected by drying and calcining sols derived from acet ylacetonate-tetraethoxysilane ethanol solutions. A mixture of magnesiu m and aluminum acetylacetonates, dissolved with Si(OC2H5)4 in an ethan ol solution in a 2:4:5 Mg:Al:Si mole ratio, was hydrolyzed, spray-drie d, and calcined to yield a glass powder of 70 angstrom primary particl e size, which sintered to densities greater-than-or-equal-to 2.5 g/cm3 and which formed mu-cordierite as the only crystalline phase below 10 00-degrees-C. Incorporation of dopant quantities of boron and phosphor us, via their alkyl esters in the hydrolysis reaction with Si(OC2H5)4 and the acetylacetonates, afforded powders which crystallized in the a lpha-phase directly after sintering to density = 2.66 g/cm3.