Nanoscale corundum powders, sintered compacts produced from these powders and method for producing the same

US7022305B2 · kind B2 · utility

Assignee

• Leibniz-Institut für Neue Materialien gemeinnützige GmbH · DE

Inventors

• Robert Drumm · Riegelsberg, DE
• Christian Goebbert · Eschau, DE
• Kai Gossmann · Riegelsberg, DE
• Ralph Nonninger · Saarburg, DE
• Helmut Schmidt · Riegelsberg, DE

Key dates

• Filing date: Jul 20, 2001
• Grant date: Apr 4, 2006
• Expiry date: Mar 1, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B2235/77
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

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.