Nanoscale corundum powders are obtained by first producing an Al2O3
precursor by adding seed crystals to an aqueous solution of an aluminium compound
and adding a base and then converting the Al2O3 precursor
into corundum by calcination at a high temperature. Before the calcination, the
salts that are present in addition to the Al2O3 precursor
are separated off. The resulting product is calcined at temperatures of 700 to
975 C. and any fines that may be present are removed. The resulting corundum
powders can be sintered at temperatures of 1200 C. to produce compacts
or components of multiple layer systems.