Method for production of α-alumina whiskers via vapor-liquid-solid deposition

alpha-alumina (alpha-Al2O3, corundum) fibers exhibit high thermal and chemical stability, as well as good mechanical properties, even at high temperatures. Such characteristics make them good candidates for use in composites. Nevertheless, very few methods of producing alpha-Al2O3 fibers are available. In the present work, we describe a method that uses aluminum pieces deposited on SiO2 powder, in an argon atmosphere, at temperatures in the range 1300degrees-1600degreesC. The alpha-Al2O3 fibers are obtained via vapor-liquid-solid deposition. The novel addition of nickel and cobalt (or their oxides) allows the use of temperatures >1500degreesC, resulting in improved fiber production. We demonstrate that the metals do not contaminate the fibers produced in this way. Finally, we also estimate the tensile strength of the AI(2)O(3) fibers produced through this method.