Patent ID: 8916088

Claim:
A method for making a hollow article, said hollow article having: an upper surface, and a lower surface; a left surface and a right surface; a proximal surface and a distal surface; at least one pair of opposing surfaces of said article having one or more openings to un-branched channels, said channels running completely through the interior of said article directly from one opposing surface to the other; said method comprising the steps: a) selecting a polymeric substrate from the group consisting of a filament, a plurality of essentially parallel filaments, a woven fabric sheet, a knitted fabric sheet, a non-woven fabric sheet, a mesh, a film, and a sheet, said polymeric substrate having exterior surfaces and optionally having interior surfaces; b) coating said exterior and interior surfaces, if any, of said substrate with an aqueous slurry comprising a gel forming binder and inorganic particles, said inorganic particles being at least one member of the group consisting of a ceramic powder, a metal powder, a cermet powder, carbon nanotubes, metal whiskers, ceramic whiskers, and their mixture to form a coated article, said slurry being applied at a temperature above its gelation temperature and having a viscosity less than or equal to 0.4 Pa-sec at the application temperature; c) optionally, removing excess slurry from the coated article d) cooling said slurry to a temperature below its gelation temperature: e) substantially drying the coated article; f) optionally repeating steps b) through e) one or more times; g) heating the coated article for periods of times, at temperatures and in atmospheres sufficient to vaporize the polymeric substrate forming a green hollow article; h) sintering the green hollow article in a protective atmosphere under conditions of time and temperatures as are required to cohere the inorganic particles into a unitary hollow article having hollow structural members with interior surfaces having essentially the initial form of the vaporized substrate.