Process for injection molding ceramic composition employing an agaroid gell-forming material to add green strength to a preform
AssigneeAllied Corporation
InventorsAnthony J. Fanelli, Robert D. Silvers
Life of this patent
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Abstract
A process for shaping parts from metallic and/or ceramic powders is disclosed. The process comprises the steps of forming a mixture comprising metal and/or ceramic powders, a gel-forming material having a gel strength, measured at a temperature between 0.degree. C. and about 22.degree. C. and a gel consisting essentially of about 4 wt. % of the gel-forming material and water, of at least about 100 g/cm.sup.2, and a gel-forming material solvent, and molding the mixture at a temperature sufficient to produce a self-supporting article comprising the powder and a gel. The preferred gel-forming material is an agaroid and the preferred molding process is injection molding.
Claims14
A method of forming an article comprising the steps of:
- (a) forming a mixture comprising
- (1) powders selected from the group consisting of metal powders, ceramic powders, and mixtures thereof,
- (2) an agaroid gel-forming material having a gel strength, measured at a temperature between 0.degree. C. and about 22.degree. C. on a gel consisting essentially of about 4 wt % of the agaroid gel-forming material and water, of at least about 500 g/cm.sup.2, and
- (3) an agaroid gel-forming material solvent;
- (b) heating the mixture to a first temperature above the gel point of the agaroid gel-forming material to solubilize the agaroid gel-forming material, said first temperature being in the range from 80.degree. C. to 100.degree. C.;
- (c) supplying the mixture to a mold;
- and
- (d) molding the mixture at a second, cooler temperature at or below the gel point of the agaroid gel-forming material to produce a self-supporting article comprising the powders and a gel comprising the agaroid gel-forming material, said second, cooler temperature being in the range from 15.degree. C. to 45.degree. C.
An injection molding process comprising the steps of:
- (a) forming a mixture comprising
- (1) powders selected from the groups of metal powders, ceramic powders and mixtures thereof,
- (2) an agaroid gel-forming material having a gel strength, measured at a temperature between O.degree. C. about 22.degree. C. on a gel consisting essentially of about 4 wt % of the agaroid gel forming material and water, of at least about 500 g/cm.sup.2,
- (3) an agaroid gel-forming material solvent, and
- (4) a carrier;
- (b) injecting the mixture into a mold, the mixture being maintained prior to the injection step at a first temperature above the gel point of the agaroid gel-forming material, said first temperature being in the range from 80.degree. C. to 100.degree. C.;
- and,
- (c) cooling the mixture in the mold to a second temperature below the gel point of the agaroid gel-forming material to form a self supporting article comprising the powders and a gel comprising the agaroid gel-forming material, said second temperature being in the range from 15.degree. C. to 45.degree. C.
A composition of matter comprising powder selected from the group consisting of metal powder, ceramic powder and mixtures thereof and, mixed therewith, an agaroid gel-forming material having a gel strength, measured at a temperature between 0.degree. C. and about 22.degree. C. on a gel consisting essentially of about 4 wt % of the agaroid gel forming material and water, of at least about 500 g/cm.sup.2.
Dependencies are inferred from the claim text.