Patent EP0150566A2 successfully refreshed from Google Patents.
EP0150566A2
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EP
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Method and apparatus for making refractory articles
Assignee: ATK Launch Systems LLC
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Filing: 1984-10-17
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Granted: —
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Expires: 2004-10-17
Abstract
Abstract A braided preform fabrication for annular refractory articles such as an integral monolithic throat section (33) and exit cone (34) of a rocket motor nozzle is formed on a mandrel (10) and includes closely spaced radially oriented carbon rods (12) that extend to a uniform length from the mandrel surface and carbon fibers (17,18,19) braided on the surface of the mandrel around the carbon rods in a triaxial braid whereby the fabrication has a 4-D fiber architecture. The density of the fabrication is increased by a process that is repeated four times and involves the steps of vacuum impregnation thereof with pitch, subjecting the impregnated preform (25) to high pressure at a temperature that is gradually increased to about 700°C to convert the pitch to coke and to form the braided preform and mandrel into a billet (31), and producing graphitization of the braided preform by subjecting the billet to an argon atmosphere in a vacuum furnace at a temperature that is gradually increased to 2,500°C. The mandrel (10) is usually removed from the billet (31) by machining after the second repetition of the process, but it may be removed at any time after the braided preform structure (25) has acquired sufficient strength to withstand the temperature and pressure of further processing.
Inventors
- 👤 Frank S. Inman
- 👤 Donald V. Lushis
- 👤 Donald C. Giedt
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 10:35
CPC Classifications
D; D04; D04C; D04C3/00; D04C3/02; D04C3/08; B; B29; B29B; B29B11/00; B29B11/14; B29B11/16; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/16; B29C70/24; D04C1/00; D04C1/06; D04C3/40; D04C3/48; F; F02; F02K; F02K9/00; F02K9/97; B29K; B29K2307/00; B29L; B29L2031/00; B29L2031/30; B29L2031/3097; D10; D10B; D10B2403/00; D10B2403/02; D10B2403/024; D10B2403/0241; D10B2403/02411; D10B2505/00; D10B2505/02
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
89 words
A braided fiber preform (25) for an annular refractory article comprising the combination of: a plurality of closely spaced annularly distributed carbon rods (12); and a tubular triaxial braid of carbon strands (17,18, 19) braided in contact with and around said carbon rods, said braid comprising a repetition of braided unit cells each of which is formed of three strands lying in substantially the same plane, each of said carbon rods (12) being oriented at a substantial angle to the plane of an associated one of said unit cells.
Claim 2
Dependent Claim
89 words
A braided fiber preform (25) for an annular refractory article comprising the combination of: a plurality of closely spaced annularly distributed carbon rods (12); and a tubular triaxial braid of carbon strands (17,18, 19) braided in contact with and around said carbon rods, said braid comprising a repetition of braided unit cells each of which is formed of three strands lying in substantially the same plane, each of said carbon rods (12) being oriented at a substantial angle to the plane of an associated one of said unit cells.
Claim 3
Dependent Claim
88 words
A braided fiber preform as specified in claim 1 further including: a mandrel (10) of high-temperature resistant material, said mandrel having an external contour that is approximately the same as the internal shape desired for the refractory article; said carbon rods (12) being inserted in the surface of said mandrel and extending radially therefrom uniformly to an extent approximately the same as that desired for the thickness of the refractory article; and said mandrel providing a supporting structure for said braided fiber preform (25) during the braiding thereof.
Claim 4
Dependent Claim
31 words
A braided fiber preform as specified in claim 2, wherein each of the strands (17,18,19) of the triaxial braid is braided with a tensile stress of about 0.25 pounds (0.113 Kg).
Claim 5
Dependent Claim
45 words
A braided fiber preform as specified in claim 2 or claim 3, wherein said braided preform is porous, and further including means to rigidize said braided preform (25) on said mandrel (10) by infiltration of carbon into the porous braided preform by chemical vapor deposition.
Claim 6
Dependent Claim
68 words
A braided fiber preform as specified in any one of claims 2 to 4, wherein the mandrel (10) has an external contour that is approximately the same as the internal shape of the throat and exit cone of a rocket motor; and wherein upon removal of said mandrel there is produced an integral monolithic throat section (33) and exit cone (34) of the nozzle of a rocket motor.
Claim 7
Dependent Claim
136 words
A braided fiber preform as specified in any one of claims 2 to 5, further including an elongated tray (13) having an edge that is shaped to fit the external contour of said mandrel (10), said edge containing a row of holes (15) that are slightly larger in diameter than the said carbon rods (12) and which are spaced apart with the spacing desired for the rods in said mandrel, the depth of the holes being slightly greater than the thickness desired for the refractory article, with a carbon rod (12) being inserted in each hole (15) whereby an entire row of carbon rods may be installed in the mandrel (10) simultaneously with precision by pressing the loaded tray (13) against the mandrel until the edge thereof is in contact with the surface of said mandrel.
Claim 8
Dependent Claim
161 words
A braided fiber preform (25) for an annular refractory article having a longitudinal contour comprising a repitition of braided unit cells in one or more tubular overlying layers, each of which unit cells comprise: a carbon rod (12) radially oriented with respect to said refractory article, the length of said carbon rod being in accordance with the desired thickness of said refractory article; a first carbon strand (17) oriented longitudinally with respect to said refractory article and positioned in contact with said carbon rod (12); a second carbon strand (18) oriented obliquely clockwise with respect to said first carbon strand (17) and positioned in contact with said carbon rod (12); and a third carbon strand (19) oriented obliquely counterclockwise with respect to said first carbon strand (17) and positioned in contact with said carbon rod (12); one of said second and third carbon strands passing over said first carbon strand and the other one thereof passing under said first carbon strand.
Claim 9
Dependent Claim
161 words
A braided fiber preform (25) for an annular refractory article having a longitudinal contour comprising a repitition of braided unit cells in one or more tubular overlying layers, each of which unit cells comprise: a carbon rod (12) radially oriented with respect to said refractory article, the length of said carbon rod being in accordance with the desired thickness of said refractory article; a first carbon strand (17) oriented longitudinally with respect to said refractory article and positioned in contact with said carbon rod (12); a second carbon strand (18) oriented obliquely clockwise with respect to said first carbon strand (17) and positioned in contact with said carbon rod (12); and a third carbon strand (19) oriented obliquely counterclockwise with respect to said first carbon strand (17) and positioned in contact with said carbon rod (12); one of said second and third carbon strands passing over said first carbon strand and the other one thereof passing under said first carbon strand.
Claim 10
Dependent Claim
108 words
A braided fiber preform as specified in claim 7 including a rigid mandrel (10) on which said braided unit cells are formed, said mandrel being made of high temperature resistant material and having an external contour that is approximately the same as the internal shape desired for the refractory article; said carbon rods (12) being inserted in the surface of said mandrel and extending radially therefrom uniformly to a length approximately the same as that desired for the thickness of said refractory article; said mandrel providing a supporting structure for said braided fiber preform (25) during the braiding thereof and during subsequent processing to increase the density thereof.
Claim 11
Dependent Claim
159 words
A braided fiber preform as specified in claim 8 further including means to facilitate the insertion of said carbon rods (12) into the surface of said mandrel (10) comprising: an elongated tray (13) having an edge that is shaped to fit the external contour of said mandrel, said edge containing a row of holes (15) which are spaced apart with the spacing desired for the rods in said mandrel, the depth of the holes being substantially the same as the thickness desired for the refractory article, with a carbon rod (12) being inserted in each hole whereby an entire row of carbon rods may be installed in the mandrel simultaneously with precision by pressing said loaded tray against the mandrel until the edge thereof is in contact with the longitudinal contour thereof, and additional rows of carbon rods may be similarly installed in the mandrel by rotating said mandrel appropriate angular increments and repeating the carbon rod installation process.
Claim 12
Independent Claim
208 words
A method of making a braided preform (25) for a refractory article comprising the steps of: partially inserting a plurality of carbon rods (12) into the exterior surface of an annular mandrel (10) having a longitudinal axis and made of high-temperature resistant, low density material, the mandrel having an external shape that is approximately the same as that desired for the inner surface of the article, with the carbon rods being spaced on the mandrel exterior surface and extending radially therefrom to a length that is approximately the same as the desired thickness of the refractory article; forming a braided annular fiber preform (25) on the mandrel by braiding carbon fibers (17,18,19) with a uniform tensile stress on each strand on the exterior surface of the mandrel in contact with and around the carbon rods (12) with the strands applied in groups of three, each group having two oblique strands (18,19) which are passed alternately over and under a longitudinal strand (17) that is positioned in the plane of the axis of the mandrel, with one of the oblique strands (18) being oblique clockwise with respect to the longitudinal strand and the other of the oblique strands (19) being oblique counterclockwise with respect to the longitudinal strand (17).
Claim 13
Independent Claim
208 words
A method of making a braided preform (25) for a refractory article comprising the steps of: partially inserting a plurality of carbon rods (12) into the exterior surface of an annular mandrel (10) having a longitudinal axis and made of high-temperature resistant, low density material, the mandrel having an external shape that is approximately the same as that desired for the inner surface of the article, with the carbon rods being spaced on the mandrel exterior surface and extending radially therefrom to a length that is approximately the same as the desired thickness of the refractory article; forming a braided annular fiber preform (25) on the mandrel by braiding carbon fibers (17,18,19) with a uniform tensile stress on each strand on the exterior surface of the mandrel in contact with and around the carbon rods (12) with the strands applied in groups of three, each group having two oblique strands (18,19) which are passed alternately over and under a longitudinal strand (17) that is positioned in the plane of the axis of the mandrel, with one of the oblique strands (18) being oblique clockwise with respect to the longitudinal strand and the other of the oblique strands (19) being oblique counterclockwise with respect to the longitudinal strand (17).
Claim 14
Dependent Claim
25 words
A method as specified in claim 10, wherein the tensile stress on each of the carbon fiber strands (17,18,19) is about 0.25 pounds (0.113 Kg).
Claim 15
Dependent Claim
176 words
A method as specified in claim 10 or claim 11, further including the steps of inserting the plurality of carbon rods (12) into the exterior surface of the mandrel (12) by the use of an elongated tray (13) having an edge that is shaped to fit the longitudinal contour of the mandrel, the edge containing a row of holes (15) which are spaced apart with the spacing desired for the rods in the mandrel, the depth of the holes being in accordance with the thickness desired for the refractory article, with a rod (12) being inserted in each hole whereby an entire, longitudinal row of holes may be installed in the mandrel simultaneously by pressing the loaded tray against the mandrel until the edge is in contact therewith; and rotating the mandrel through desired successive angular increments and repeating, each time, the last mentioned step until all of the rods have been inserted in the mandrel thereby to insure uniformity of spacing and of the radial extent of the rods from the surface of the mandrel.
Claim 16
Independent Claim
46 words
A method as specified in any one of claims 10 to 12, wherein the braided preform (25) is porous and further including the step of rigidifying the braided preform on the mandrel (10) by infiltration of carbon into the porous braided preform by chemical vapor deposition.
Claim 17
Independent Claim
64 words
A method as specified in any one of claims 10 to 13, further including the steps of impregnating the braided preform (25) with a thermo-setting material in a vacuum and following such impregnation subjecting the braided preform to heat and pressure to produce graphitization to increase the density of said braided preform, and repeating these steps until the braided preform has the desired density.
References Cited (Backward Citations)
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