Fabrication of dual structure ceramics by a single step process
AssigneesUniversita' Degli Studi Di Roma "Tor Vergata", University of Florida Research Foundation, Inc.
InventorsFrancesco Basoli, Silvia Licoccia, Eric D. Wachsman, Enrico Traversa
Life of this patent
Estimating the term…
Abstract
The subject invention discloses a method for the preparation of a dual structure cellular ceramic object where a dispersion of a ceramic precursor a chain-growth or step-growth polymer precursor and a solvent is heated to a first temperature at a first rate followed by heating to a second temperature at a second rate and holding the temperature to form a sintered dual structure cellular ceramic object which is then cooled at a third rate to room temperature. The dual structure cellular ceramic object has a dense surface layer over at least a portion of the object that abruptly yet smoothly and continuously transitioning into a porous ceramic.
Claims12
A method for manufacturing a dual structure cellular ceramic object, comprising the steps of:
- forming a fluid dispersion comprising a ceramic precursor and a chain-growth or step-growth organic polymer precursor in a solvent;
- placing said fluid dispersion in a semi-rigid mold or flexible mold or extruding said fluid dispersion through a die to form a shaped object;
- heating said fluid dispersion at a first rate to a first temperature, wherein said first rate is a constant temperature ramp and wherein chain-growth or step-growth organic polymer precursor is converted into a polymer and said polymer is decomposed;
- further heating at a second rate to a second temperature, wherein said second rate is a constant temperature ramp;
- holding said second temperature for a period of time, wherein a sintered dual structure cellular ceramic object is formed, said ceramic object comprising a dense surface layer over at least a portion of said cellular ceramic object adjacent to a porous ceramic structure, wherein said dense surface layer over at least a portion of said cellular ceramic object formed where contact occurred between said shaped object with said semi-rigid mold or flexible mold or said die;
- and
- cooling said cellular ceramic object to room temperature at a third rate.
Dependencies are inferred from the claim text.