Michael E. Rorabaugh - Seattle WA Darryl F. Garrigus - Issaquah WA Juris Verzemnieks - Tacoma WA
Assignee:
The Boeing Company - Seattle WA
International Classification:
B32B 312
US Classification:
501 951, 501 80, 252 62, 442136
Abstract:
A fibrous ceramic mat is molded from a slurry of ceramic fibers and/or ceramic micropartides and/or a metal. The mat is impregnated with a sol prior to drying. A catalyst for the sol is introduced into the mat to cause the sol to gel. The sol-gel binder forms bonds so that the mat is dimensionally stabilized. The mat is dried to produce the desired ceramic insulation that has preferably a consistent microstructure and a fully gelled sol-gel binder through its entire thickness. If we use a metal, it corrodes (i. e. , oxidizes) or otherwise reacts to form a refractory binder that augments the sol and reduces the need to infuse sol incrementally to achieve strength. Using metal powder significantly reduces the cost of manufacture.
Ronald W. Brown - Des Moines WA, US Marc R. Matsen - Seattle WA, US Wesley B. Crow - Bellevue WA, US Stephen G. Moore - Seattle WA, US David S. Nansen - Bellevue WA, US Charles W. Newquist - Issaquah WA, US Juris Verzemnieks - Puyallup WA, US
Assignee:
The Boeing Company - Chicago IL
International Classification:
H05B006/64
US Classification:
219759, 219602, 219633
Abstract:
An apparatus and method for consolidating a composite workpiece are provided. The apparatus includes an electromagnetic field generator for inducing a current and thereby heating a susceptor in thermal communication with the workpiece. The workpiece is supported by one or more support tools, each of which transmits the electromagnetic field so that the support tools are not substantially heated by the electromagnetic field. Thus, the time and energy required for heating the workpiece are reduced relative to conventional consolidation techniques.
Ronald W. Brown - Des Moines WA, US Wesley B. Crow - Bellevue WA, US Marc R. Matsen - Seattle WA, US Stephen G. Moore - Seattle WA, US David S. Nansen - Bellevue WA, US Charles W. Newquist - Issaquah WA, US Juris Verzemnieks - Puyallup WA, US
Assignee:
The Boeing Company - Chicago IL
International Classification:
H05B 6/64
US Classification:
219634, 219759, 219633
Abstract:
An apparatus and method for consolidating a composite workpiece are provided. The apparatus includes an electromagnetic field generator for inducing a current and thereby heating a susceptor in thermal communication with the workpiece. The workpiece is supported by one or more support tools, each of which transmits the electromagnetic field so that the support tools are not substantially heated by the electromagnetic field. Thus, the time and energy required for heating the workpiece are reduced relative to conventional consolidation techniques.
Method For Making .Alpha.-Si.sub.3 N.sub.4 Whiskers And Articles Therefrom
A method for producing. alpha. -silicon nitride whiskers. Silicon is blended with amorphous silicon nitride and a pore-forming composition particles able to be removed without leaving a residue, such as naphthalene particles. The mixture is compacted to a desired shape, after which the pore-forming particles are removed from the mixture to form a porous silicon precursor compact having the desired shape. The silicon precursor is reacted with a substance that releases free nitrogen, such as nitrogen or dry ammonia. The reaction is carried out at a temperature sufficiently high to form an identically shaped porous compact of. alpha. -silicon nitride whiskers but sufficiently low to avoid subliming substantially all of the formed whiskers. Preferably, the reaction is carried out in a range between about 1100. degree. C. and 1500. degree. C. The shaped porous compact of. alpha.
Boron Nitride Coated Ceramic Fibers And Coating Method
Frederick H. Simpson - Seattle WA Juris Verzemnieks - Tacoma WA
Assignee:
The Boeing Company - Seattle WA
International Classification:
D04H 158 B32B 900
US Classification:
428288
Abstract:
Oxide-based ceramic fibers are treated in a novel process to create a substantially uniform boron nitride barrier coating at their surface. The process involves heating the fibers in a nitriding atmosphere at between about 2200-2600. degree. F. to create a BN coating at the surface of the fiber from boron initially within the fiber.
Michael E. Rorabaugh - Seattle WA Darryl F. Garrigus - Issaquah WA Juris Verzemnieks - Tacoma WA
Assignee:
The Boeing Company - Seattle WA
International Classification:
C04B 3800 C04B 3580
US Classification:
501 80
Abstract:
A fibrous ceramic mat is molded from a slurry of ceramic fibers and/or ceramic microparticles and/or a metal. The mat is impregnated with a sol prior to drying. A catalyst for the sol is introduced into the mat to cause the sol to gel. The sol-gel binder forms bonds so that the mat is dimensionally stabilized. The mat is dried to produce the desired ceramic insulation that has preferably a consistent microstructure and a fully gelled sol-gel binder through its entire thickness. When a metal is used, it corrodes (i. e. , oxidizes) or otherwise reacts to form a refractory binder that augments the sol and reduces the need to infuse sol incrementally to achieve strength. Using metal powder significantly reduces the cost of manufacture.
Frederick H. Simpson - Seattle WA Juris Verzemnieks - Tacoma WA
Assignee:
The Boeing Company - Seattle WA
International Classification:
D04H 158 B32B 900
US Classification:
428288
Abstract:
Oxide-based ceramic fibers are treated in a novel process to create a substantially uniform boron nitride barrier coating at their surface. The process includes the step of heating the fiber, preferably an aluminoborosilicate fiber like NEXTEL, for between about 5-90 minutes in a nitriding atmosphere of ammonia, hydrogen and nitrogen at a temperature of between about 2200. degree. -2600. degree. F. to diffuse boron from the fiber to the surface of the fiber where it reacts to form the boron nitride coating.
Alumina-Based Protective Coating For Ceramic Materials
Michael E. Rorabaugh - Seattle WA Charles W. Newquist - Issaquah WA Juris Verzemnieks - Tacoma WA
Assignee:
The Boeing Company - Seattle WA
International Classification:
B32B 1700
US Classification:
428365
Abstract:
A coated ceramic has alumina as an amorphous residue from an alumina sol containing alumina powder or and, optionally, a high emittance powder. The alumina powder alters the rheology and wetting characteristics of the sol to aid in forming the residue and increases the alumina concentration (% solids) in the residue. The high emittance powder radiates heat out of the residue and away from the ceramic when the coated ceramic is heated, such as during orbital reentry.