Abstract:
A method to produce a self-supporting ceramic structure by oxidation of a liquid phase parent metal with a vapor phase oxidizing environment includes applying a layer having at least one dopant material to at least a portion of a parent metal of the type having an oxide skin which is normally impervious to an oxiding atmosphere. Upon temperature elevation, the parent metal becomes molten and due to the dopant material in the layer, is caused to migrate through the oxide skin and layer so as to be exposed to the oxidizing atmosphere whereupon an oxide of the parent metal is formed. Migration of the parent metal continues through the formed parent metal oxide to grow layer upon layer of parent metal oxide to thus achieve a self-supporting oxide structure.
Abstract:
A method of making self-supporting ceramic composite structures having filler embedded therein includes infiltrating a permeable mass of filler with polycrystalline material comprising an oxidation reaction product obtained by oxidation of a parent metal such as aluminum and optionally containing therein non-oxidized constituents of the parent metal. The structure is formed by placing a parent metal adjacent to a permeable filler and heating the assembly to melt the parent metal and provide a molten body of parent metal which is contacted with a suitable vapor-phase oxidant. Within a certain temperature region and optionally aided by one or more dopants in or on the parent metal, molten parent metal will migrate through previously formed oxidation reaction product into contact with the oxidant, causing the oxidation reaction product to grow so as to embed the adjacent filler and provide the composite structure.