Chemically Bonded Composite Sol–Gel Alumina Coatings
Abstract:This communication introduces chemically bonded (CB) composite sol–gel (SG) technology. The composite includes majority (>80 vol%) particulate filler, the balance being SG-derived bonding phase. Ceramic bond formation in such a composite is induced through chemical reaction rather than through sintering. In the particular variant of the process presented here, the reactivity of the SG-derived alumina ceramics toward phosphates, such as aluminum phosphate or phosphoric acid, is explored to produce a ceramic (reaction) bond in the system without sintering. This allows attaining structural integrity of the composite at relatively low temperatures of 300°C. Several examples of 40–200 m thick films of CB alumina on stainless steel, Mg and Al, Ni, and on carbon fiber-reinforced epoxy are discussed.
Document Type: Research Article
Affiliations: Materials Engineering Department, UBCeram—The University of British Columbia, Vancouver, BC, Canada V6T 1Z4
Publication date: 2005-09-01