Forming of complex high performance ceramic and metallic shapes
AssigneeCeramics Process Systems Corporation
InventorsMark A. Occhionero, Bruce E. Novich, Cathryn A. Sundback
Life of this patent
Estimating the term…
Abstract
Dense, flaw free, complex, 3-dimensional, metal or refractory shapes are formed by preparing a low viscosity, pourable aqueous-based suspension. The aqueous suspension preferably contains ceramic or metal particulates, water, and a compatible mixture of additives for performing dispersant, cryoprotectant, and strength enhancing functions. The low viscosity slip is cast or injection molded at low pressure into a complex mold, frozen, demolded, and freeze dried without the formation of a continuous liquid phase. The green part is subsequently sintered by conventional techniques to achieve a dense part.
Claims13
A process for producing a sintered ceramic or metallic article, comprising:
- a. providing a stable, pourable suspension consisting essentially of at least about 35 vol % solid ceramic particles or metallic particles or combinations thereof and a vehicle composed of a dispersant selected from the group consisting of acrylate-based polymeric polyelectrolytes and polyethylene imines, at least one cryoprotectant, and the remainder water;
- b. shaping the suspension in a closed mold at a pressure of less than about 200 psi;
- c. chilling the mold temperature to less than the freezing point of the vehicle;
- d. solidifying the shaped suspension by rapidly freezing the shaped suspension;
- e. freeze drying the solidified shape below the freezing point of the vehicle without the formation of a continuous liquid phase;
- and
- f. firing the dried shape.
Dependencies are inferred from the claim text.