Method of forming ecoceramic-based silicon-carbide tooling for composites and method for forming composites using same
AssigneeLockheed Martin Corporation
InventorSlade H. Gardner
Life of this patent
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Abstract
A method is provided for forming items from ecoceramic-based silicon-carbide. A wood preform is machined to a general shape having over- or undersized dimensions. The preform is pyrolyzed to transform the wood of the preform to a porous, carbonaceous material that retains the general shape of the preform. The preform is then machined to final, net-shape dimensions and immersed in liquid silicon or silicon alloy that penetrates and infuses the preform. The infused preform is held at a temperature sufficient to cause the transformation of the material in the preform to silicon carbide, completing formation of the item. Also provided is a method of forming ecoceramic-based tooling and composite components using the tooling.
Claims36
A method of forming a silicon-carbide item, the method comprising:
- (a) forming a preform from wood, then
- (b) applying a vacuum to substantially surround the perform, then
- (c) heating the preform under pressure to a first temperature in an autoclave, then
- (d) heating the preform to a second temperature in a furnace at atmospheric pressure to pyrolyze the preform, the second temperature being higher than the first temperature;
- and then
- (e) infusing the preform with a liquid containing silicon for forming a silicon-carbide item that retains the shape of the preform.
A method of forming a silicon-carbide item, the method comprising:
- (a) forming a preform from wood, then
- (b) covering the preform with a vacuum bag and evacuating air from the bag, then
- (c) heating the preform and vacuum bag under pressure to a drying temperature in an autoclave, then
- (d) removing the vacuum bag and heating the preform under pressure to a first temperature in the autoclave, the first temperature being higher than the drying temperature;
- then
- (e) heating the preform to a second temperature in a furnace at atmospheric pressure to pyrolyze the preform, the second temperature being higher than the first temperature;
- and then
- (f) infusing the preform with a liquid containing silicon for forming a silicon-carbide item that retains the shape of the preform.
A method of forming composite component, the method comprising:
- (a) forming a preform from wood, the preform being shaped as a mold;
- then
- (b) pyrolyzing the preform, then
- (c) infusing the preform with liquid containing silicon, then
- (d) holding the infused preform at a selected temperature to form a silicon-carbide tool that retains the shape of the preform, the tool having at least one tooling surface for receiving layers of composite material;
- then
- (e) applying the layers of composite material to the tooling surface to form the component, then
- (f) curing the component on the tooling surface, and then
- (g) removing the cured component from the tool.
A method of forming a silicon-carbide item, the method comprising:
- (a) forming a preform from wood, then
- (b) heating the preform under pressure to a first temperature in an autoclave, the step of heating the perform under pressure including the steps of covering the preform with a vacuum bag, evacuating air from the bag, then heating the preform and vacuum bag to a drying temperature lower than the first temperature, then removing the vacuum bag and heating the preform to the first temperature, then
- (c) heating the preform to a second temperature in a furnace at atmospheric pressure to pyrolyze the preform, the second temperature being higher than the first temperature, and then
- (d) infusing the preform with a liquid containing silicon for forming a silicon-carbide item that retains the shape of the preform.
A method of forming a silicon-carbide item, the method comprising:
- (a) forming a preform from wood, then
- (b) machining a recess into an upper surface of the perform after the perform is formed, then
- (c) heating the preform under pressure to a first temperature in an autoclave, the step of heating the perform under pressure including the steps of covering the preform with a vacuum bag, evacuating air from the bag, then heating the preform and vacuum bag to a drying temperature lower than the first temperature, then removing the vacuum bag and heating the preform to the first temperature, then
- (d) heating the preform to a second temperature in a furnace at atmospheric pressure to pyrolyze the preform, the second temperature being higher than the first temperature, and then
- (e) infusing the preform with a liquid containing silicon for forming a silicon-carbide item that retains the shape of the preform.
Dependencies are inferred from the claim text.