Method for producing structures by isostatic compression
First Claim
1. In an isostatic compression process for forming compression structures, the steps comprising:
- (a) establishing a suspension of colloidal size matrix powders in a carrier liquid;
(b) providing a die chamber comprising a self-supporting cage structure formed of material enabling the transmission of pressure from the exterior to the interior thereof and an expansible and conformable bladder within said cage structure, said die chamber having a filter opening and a filter disposed therein which is permeable to filtrate from said colloidal suspension under an applied pressure but substantially impermeable to said matrix powders;
(c) incorporating said colloidal suspension into the interior of said bladder; and
(d) isostatically imposing an elevated pressure on said bladder containing said colloidal suspension within said die chamber at a pressure sufficient to dispel carrier liquid filtrate through said filter opening and maintaining said pressure for period sufficient to expel at least 20% of the liquid originally contained in said colloidal suspension through said filter opening.
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Accused Products
Abstract
A process for producing a green composite structure by isostatic compression and filtration. A suspension of colloidal size matrix powders is established in a carrier liquid. The suspension is incorporated into a die chamber having a filter opening containing a filter which is permeable to filtrate from the suspension under applied pressure but substantially impermeable to the matrix powders. An elevated pressure is isostatically imposed on the colloidal suspension within the die chamber. The pressure is maintained for a period of time to expel at least 20% of the liquid originally in the colloidal suspension through the filter opening. A specific die chamber comprises a rigid cage structure and an expandable bladder within the cage structure into which the colloidal suspension is introduced. The cage structure is disposed within a pressure vessel which can be initially evacuated to cause the bladder to conform to the cage structure and then pressurized with fluid for the isostatic compression procedure.
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Citations
25 Claims
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1. In an isostatic compression process for forming compression structures, the steps comprising:
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(a) establishing a suspension of colloidal size matrix powders in a carrier liquid; (b) providing a die chamber comprising a self-supporting cage structure formed of material enabling the transmission of pressure from the exterior to the interior thereof and an expansible and conformable bladder within said cage structure, said die chamber having a filter opening and a filter disposed therein which is permeable to filtrate from said colloidal suspension under an applied pressure but substantially impermeable to said matrix powders; (c) incorporating said colloidal suspension into the interior of said bladder; and (d) isostatically imposing an elevated pressure on said bladder containing said colloidal suspension within said die chamber at a pressure sufficient to dispel carrier liquid filtrate through said filter opening and maintaining said pressure for period sufficient to expel at least 20% of the liquid originally contained in said colloidal suspension through said filter opening. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. In an isostatic compression process for forming a reinforced green composite structure in a self sustaining shaped configuration suitable for sintering, the steps comprising:
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(a) establishing a suspension of colloidal size refractory matrix powders and refractory reinforcing whiskers in a carrier liquid; (b) providing a die chamber comprising a self-supporting cage structure formed of material enabling the transmission of pressure from the exterior thereof and an expansible and conformable bladder within said cage structure, said die chamber having a filter opening and a filter disposed therein which is permeable to filtrate from said colloidal suspension under an applied pressure but substantially impermeable to said refractory ceramic powder; (c) incorporating said suspension into the interior of said bladder; and (d) isostatically imposing an elevated pressure on said bladder containing said colloidal suspension within said die chamber at a pressure sufficient to dispel carrier liquid filtrate through said filter opening and maintaining said pressure for period sufficient to expel at least 20% of the liquid originally contained in said colloidal suspension through said filter opening to arrive at a green composite structure capable of retaining its configuration upon removal from said die chamber. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification