Abstract:
Integrated ceramic matrix composite components for use in gas turbine engines are disclosed along with methods for making the same. The methods include coinfiltrating a greenbody assembly with ceramic matrix to produce an integrated component.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/182,882, filed 22 Jun. 2015, the disclosure of which is now expressly incorporated herein by reference. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    The present disclosure relates generally to ceramic matrix composite component manufacture, and more specifically to joining of ceramic matrix composite components. 
       BACKGROUND 
       [0003]    Reinforced ceramic matrix composites can be well suited for structural applications because of their potential toughness, thermal resistance, high temperature strength and chemical stability. These composites can be produced by the addition of whiskers, fibers, platelets, or other reinforcements to a ceramic matrix. 
         [0004]    Joining ceramic matrix composite components to one another can present challenges. In some joined ceramic matrix composite component assemblies, metallic braze joints couple separate ceramic matrix composite components to provide an integrated assembly. These metallic braze joints can degrade the mechanical integrity of the ceramic matrix composite components. In addition, these metallic braze joints can reduce the temperature capability of the ceramic matrix components due to suppression of a silicon melting point within the ceramic matrix composite components. 
       SUMMARY 
       [0005]    The present disclosure may comprise one or more of the following features and combinations thereof. 
         [0006]    A method of making an integrated ceramic matrix composite component for use in a gas turbine engine is disclosed in this paper. The method may include manufacturing a first green body subpart formed to include a first slot, manufacturing a second green body subpart formed to include a second slot, inserting a green body biscuit into the first slot of the first green body subpart and the second slot of the second green body subpart to create a green assembly with a joint between the first green body subpart and the second green body subpart, and slurry infiltrating the green assembly with ceramic-containing matrix to integrally join the green assembly and produce an integrated ceramic matrix composite component. 
         [0007]    In some embodiments, the method may include vapor infiltrating the first green body subpart, the second green body subpart, and the green body biscuit with ceramic-containing matrix to at least partially rigidify the first green body subpart, the second green body subpart, and the green body biscuit. The step of vapor infiltrating may be performed before the step of inserting the green body biscuit into the first slot of the first green body subpart and the second slot of the second green body subpart to create a green assembly. 
         [0008]    In some embodiments, manufacturing the first green body subpart may include laying up a plurality of reinforcement sheets. The method may include chemical vapor infiltrating the first green body subpart with ceramic-containing matrix to at least partially rigidify the first green body subpart after laying up the plurality of reinforcement sheets. At least some of the plurality of reinforcement sheets may be formed to include cutouts that cooperate to define the first slot before the step of vapor infiltrating the first green body subpart with ceramic-containing matrix. 
         [0009]    In some embodiments, the method may include machining at least some of the plurality of reinforcement sheets to define the first slot. This machining may take place after the step of chemical vapor infiltrating the first green body subpart with ceramic-containing matrix. 
         [0010]    In some embodiments, each of the plurality of reinforcement sheets included in the first green body subpart may comprise a ceramic-containing fiber. The ceramic-containing fiber may comprise silicon-carbide and the ceramic-containing matrix comprises silicon-carbide. 
         [0011]    In some embodiments, the method may include melt infiltrating the first green body subpart, the second green body subpart, and the green body biscuit with ceramic-containing matrix to integrally join the green assembly. The step of melt infiltrating may be performed after the step of slurry infiltrating the green assembly with ceramic-containing matrix. 
         [0012]    According to another aspect of the present disclosure, a method of making an integrated ceramic matrix composite component for use in a gas turbine engine is taught. The method may include the steps of chemical vapor infiltrating a first green body subpart, a second green body subpart, and a green body biscuit to at least partially rigidify the first green body subpart, the second green body subpart, and the green body biscuit, inserting the green body biscuit into a first slot formed in the first green body subpart and a second slot formed in the second green body subpart, and slurry infiltrating the first green body subpart, the second green body subpart, and the green body biscuit to produce an integrated ceramic matrix composite component. 
         [0013]    In some embodiments, the step of slurry infiltrating the first green body subpart, the second green body subpart, and the green body biscuit may be performed after inserting the green body biscuit into the first slot formed in the first green body subpart and the second slot formed in the second green body subpart. The step of chemical vapor infiltrating may be performed before the step of inserting the green body biscuit into the first slot of the first green body subpart and the second slot of the second green body subpart. 
         [0014]    In some embodiments, the first green body subpart may include a plurality of reinforcement sheets adapted to be suspended in ceramic-containing matrix. At least some of the plurality of reinforcement sheets may be formed to include cutouts that cooperate to define the first slot before the step of vapor infiltrating the first green body subpart with ceramic-containing matrix. 
         [0015]    In some embodiments, the method may include machining at least some of the plurality of reinforcement sheets to define the first slot after the step of chemically infiltrating the first green body subpart with ceramic-containing matrix. 
         [0016]    In some embodiments, each of the plurality of reinforcement sheets included in the first green body subpart may comprise a ceramic-containing fiber. 
         [0017]    In some embodiments, the method may include melt infiltrating the first green body subpart, the second green body subpart, and the green body biscuit with ceramic-containing matrix. 
         [0018]    According to yet another aspect of the present disclosure, an integrated ceramic-matrix composite component for use in a gas turbine engine is taught. The component may include a first subpart formed to include a first blind slot, a second subpart formed to include a second blind slot, and a biscuit that extends into the first blind slot and the second blind slot to form a joint between the first subpart and the second subpart, wherein the joint is coinfiltrated with ceramic-containing matrix material to integrally join the first subpart, the second subpart, and the biscuit. 
         [0019]    These and other features of the present disclosure will become more apparent from the following description of the illustrative embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a perspective view of an integrally-joined ceramic matrix composite component showing that the component includes a first ceramic matrix composite subpart, a second ceramic matrix composite subpart, and a single round disk-shaped biscuit that is received in slots formed in the first and the second subparts to form a joint between the first and the second subparts; 
           [0021]      FIG. 2  is an exploded perspective view of the integrally-joined ceramic matrix composite component showing slots formed in the first ceramic matrix composite subpart and the second ceramic matrix composite subpart sized to receive the single round disk-shaped biscuit; 
           [0022]      FIG. 3  is a perspective view of a first method for making the integrally-joined ceramic matrix composite component of  FIG. 1 ; 
           [0023]      FIG. 4  is a diagrammatic view of the first method shown in  FIG. 3  for making the integrally-joined ceramic matrix composite component of  FIG. 1 ; 
           [0024]      FIG. 5  is a perspective view of a second method for making the integrally-joined ceramic matrix composite component of  FIG. 1 ; 
           [0025]      FIG. 6  is a diagrammatic view of the second method shown in  FIG. 5  for making the integrally-joined ceramic matrix composite component of  FIG. 1 ; 
           [0026]      FIG. 7  is a perspective view of a second integrally-joined ceramic matrix composite component adapted to be made by one of the methods shown in  FIGS. 3-6  showing that the component includes a first ceramic matrix composite subpart, a second ceramic matrix composite subpart, and a pair of round disk-shaped biscuits; 
           [0027]      FIG. 8  is a perspective view of a third integrally-joined ceramic matrix composite component adapted to be made by one of the methods shown in  FIGS. 3-6  showing that the component includes a first ceramic matrix composite subpart, a second ceramic matrix composite subpart, and a pair of oblong oval-shaped biscuits; 
           [0028]      FIG. 9  is a perspective view of a fourth integrally-joined ceramic matrix composite component adapted to be made by one of the methods shown in  FIGS. 3-6  showing that the component includes a first ceramic matrix composite subpart, a second ceramic matrix composite subpart, and a single oblong oval-shaped biscuit; 
           [0029]      FIG. 10  is a perspective view of a fifth integrally-joined ceramic matrix composite component adapted to be made by one of the methods shown in  FIGS. 3-6  showing that the component includes a first ceramic matrix composite subpart, a second ceramic matrix composite subpart, and a pair of rectangular biscuits; 
           [0030]      FIG. 11  is a perspective view of a sixth integrally-joined ceramic matrix composite component adapted to be made by one of the methods shown in  FIGS. 3-6  showing that the component includes a first ceramic matrix composite subpart, a second ceramic matrix composite subpart, and a single rectangular biscuit; and 
           [0031]      FIG. 12  is a perspective view of a seventh integrally-joined ceramic matrix composite component adapted to be made by one of the methods shown in  FIGS. 3-6  showing that the component includes a first ceramic matrix composite subpart, a second ceramic matrix composite subpart, and a single diamond-shaped biscuit. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments illustrated in the drawings and specific language will be used to describe the same. 
         [0033]    An integrally joined component  10  adapted for use in a gas turbine engine is shown in  FIG. 1 . The component  10  illustratively comprises ceramic matrix composite materials and is made up of a first subpart  14 , a second subpart  14 , and a biscuit  16 . The biscuit  16  extends into a first blind slot  13  formed in the first subpart  12  and into a second blind slot  15  formed in the second subpart  14  to form a joint  20 . The joint  20  is coinfiltrated with ceramic-containing matrix material to integrally join the first subpart  12 , the second subpart  14 , and the biscuit  16 . 
         [0034]    The first subpart  12 , the second subpart  14 , and the biscuit  16  are each made up of stacked sheets or plies  121 ,  122 ,  141 ,  142 ,  161 ,  162  of reinforcement material that is suspended in a ceramic matrix as shown in  FIG. 3 . In the illustrative embodiment, fibers of the stacked plies comprise silicon-carbide but may comprise other ceramic-containing materials or other non-ceramic materials. In other embodiments, one or more of the first subpart  12 , the second subpart  14 , and the biscuit  16  may comprise other configurations of reinforcement fibers suspended in a matrix, monolithic ceramic-containing materials, or other materials adapted for use in a gas turbine engine. 
         [0035]    In the illustrative embodiment, the biscuit  16  is a round, disk-shaped component as shown in  FIG. 2 . The first and the second blind slots  13 ,  15  are shaped to receive substantially all of the biscuit  16  so that end faces  22 ,  24  of the first subpart  12  and the second subpart  14  face and engage one another in the illustrative component  10 . The biscuit  16  is spaced apart from an outer surface  25  of the component  10 . 
         [0036]    For example, the integrally joined component  10  or similar components may be used in a gas turbine engine to provide a turbine blade track, in a combustion liner, a heat shield or the like. The integrally joined component  10  may be adapted for use in very high temperature environments and may be used in various applications requiring high temperature service. 
         [0037]    A first method  1000  of making the integrally joined ceramic matrix composite component  10  is shown in illustratively in  FIG. 3  and diagrammatically in  FIG. 4 . A step  1100  of the method  1000  is manufacturing green bodies to be coinfiltrated. Particularly, in step  1100 , a first green body subpart  1012  formed to include a first slot  1013 , a second green body subpart  1014  formed to include a second slot  1015 , and a green body biscuit  1016  are manufactured. 
         [0038]    The step  1100  of manufacturing green bodies includes laying up preshaped reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  in a step  1110 . The step  1100  of manufacturing green bodies also includes at least partially rididifying the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  via chemical vapor deposition (CVD) in a step  1120  as shown in  FIGS. 3 and 4 . In some embodiments, rigidizing the reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  in the step  1120  may alternatively or additionally include chemical vapor infiltration (CVI). Additionally, in some embodiments, the step  1100  may include an optional machining of the rigidized reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  to provide green bodies in a specific shape in a step  1130  as shown in  FIG. 4 . 
         [0039]    At least some of the plurality of reinforcement sheets  121 ,  122 ,  141 ,  142  that are used to make up the green body subparts  1012 ,  1014  are preshaped or formed to include cutouts  125 ,  145  that cooperate to define slots in the green body subparts  1012 ,  1014  as shown in  FIG. 3 . The plurality of reinforcement sheets  161 ,  162  are preshaped to provide a round shape of the green body biscuit  1016  when rigidized. 
         [0040]    During rigidization of the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  in the step  1120 , CVD or CVI may be used to build up one or more layers of matrix on the ceramic fibers included in the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162 . The one or more layers may include a silicon carbide layer. Furthermore, an intermediate layers such as boron nitride may be deposited prior to the silicon carbide layer. CVD may follow the same thermodynamics and chemistry. CVI and CVD may be non-line of sight processes such that CVI and CVD may occur completely within a furnace as shown in  FIG. 3 . 
         [0041]    The starting material for CVI may include a gaseous precursor that undergoes a chemical reaction to yield a solid and may be performed at temperatures between about 900° C. and about 1300° C. CVI may be performed at relatively low pressure and may use multiple cycles in the furnace. Silicon carbide may also be deposited to build up one or more layers on the fibers while the preform is in the reactor. The silicon carbide may provide additional protection to the fibers and may also increase the stiffness of the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  and the tip preform. In some embodiments, boron nitride may be deposited prior the silicon carbide to provide further beneficial mechanical properties to the fibers. 
         [0042]    The laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  may be taken out of the furnace after a first pass through the reactor and weighed. If the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  are not at a target weight they may go through the reactor for another run, which may occur as many times as necessary in order to achieve the target weight. The target weight may be determined by the final part to be made. CVI or CVD may form a preform with a porosity of between about 40% and about 60%. If the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  are at the target weight the method  1000  may proceed. 
         [0043]    A step  1200  of the method  1000  is assembling green bodies to be coinfiltrated as shown in  FIGS. 3 and 4 . Particularly, in step  1200 , the green body biscuit  1016  is inserted into a first slot  1013  of the first green body subpart  1012  and a second slot  1015  of the second green body subpart  1014  to create a green assembly  1010  with a green joint  1020  between the first green body subpart  1012  and the second green body subpart  1014 . 
         [0044]    In some embodiments, the biscuit  1016  may be fully processed (rigidized) prior to assembly in step  1200 . Such fully processed biscuits  1016  may be preferred when machining of the biscuits  1016  ahead of assembly is required. 
         [0045]    A step  1300  of the method  1000  is slurry infiltrating the green assembly  1010  as shown in  FIGS. 3 and 4 . Slurry infiltration in step  1300  may include infiltrating the green assembly  1010  with slurry. Dispersing the slurry throughout the green assembly  1010  may include immersing the preforms in the slurry composition. The slurry may include particles of silicon carbide and optionally carbon. The slurry may flow into the spaces, pores, or openings between the fibers of the green assembly  1010  such that the slurry particles may uniformly impregnate the pores of the green assembly  1010  and reside in the interstices between fibers of the green assembly  1010 . The slurry infiltration process may form a resultant matrix for the component with a porosity of between about, or between precisely, 35% and about 50%. 
         [0046]    Prior to immersion, the fibers of the green assembly  1010  may optionally be prepared for slurry infiltration by exposing the fibers to a solution including, for example, water, solvents, surfactants and the like to aid impregnation of the fibers. Optionally, a vacuum may be drawn prior to slurry introduction to purge gas from the green assembly  1010  and further enhance impregnation. Slurry infiltration may be conducted at any suitable temperature such as at room temperature (about 20° C. to about 35° C.). The slurry infiltration may be enhanced by application of external pressure after slurry introduction such as at one atmosphere pressure gradient. 
         [0047]    A step  1400  of the method  1000  includes melt infiltration of the green assembly  1010  as shown in  FIGS. 3 and 4 . During melt infiltration a molten metal or alloy may wick between the openings of the green assembly  1010 . In various embodiments, the molten metal or alloy may have composition that includes silicon, boron, aluminum, yttrium, titanium, zirconium, oxides thereof, carbides thereof, and mixtures and combinations thereof. In some instances, carbonaceous powder may be added to assist the melt infiltration. The molten metal or alloy may wick into the remaining pores of the preform through capillary pressure. For example, molten silicon metal may wick into the pores and form silicon carbide to create a matrix between the fibers resulting in a relatively dense integrally joined component  10  compared to the green assembly  1010 . For example, after the green assembly  1010  has been densified, the integrally joined component  10  may have a porosity of between about 1 percent and about 10 percent by volume. 
         [0048]    In one example, a temperature for melt infiltration of silicon may be between about 1400° C. and about 1500° C. The duration of the melt infiltration may be between about 15 minutes and 4 hours. The melt infiltration process may optionally be carried out under vacuum, but in other embodiments melt infiltration may be carried out with an inert gas under atmospheric pressure to limit evaporation losses. The co-infiltration processes described herein may create the integrally joined component  10  in which the first subpart  12 , the second subpart  14 , and the biscuit  16  are a one-piece, continuous structure. 
         [0049]    A second method  2000  of making the integrally joined ceramic matrix composite component  10  is shown in illustratively in  FIG. 5  and diagrammatically in  FIG. 6 . A step  2100  of the method  1000  is manufacturing green bodies to be coinfiltrated. Particularly, in step  2100 , a first green body subpart  1012  formed to include a first slot  1013 , a second green body subpart  1014  formed to include a second slot  1015 , and a green body biscuit  1016  are manufactured. 
         [0050]    The step  2100  of manufacturing green bodies includes laying up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  in a step  2110 . The step  2100  of manufacturing green bodies also includes at least partially rididifying the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  via chemical vapor deposition (CVD) in a step  2120  as shown in  FIGS. 5 and 6 . In some embodiments, rigidizing the reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  in the step  2120  may alternatively or additionally include chemical vapor infiltration (CVI). Additionally, the step  2100  includes machining of the rigidized laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  to provide green bodies in a specific shape in a step  1130  as shown in  FIG. 5 . 
         [0051]    During rigidization of the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  in the step  2120 , CVD or CVI may be used to build up one or more layers of matrix on the ceramic fibers included in the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162 . The one or more layers may include a silicon carbide layer. Furthermore, an intermediate layers such as boron nitride may be deposited prior to the silicon carbide layer. CVD may follow the same thermodynamics and chemistry. CVI and CVD may be non-line of sight processes such that CVI and CVD may occur completely within a furnace as shown in  FIG. 5 . 
         [0052]    The starting material for CVI may include a gaseous precursor that undergoes a chemical reaction to yield a solid and may be performed at temperatures between about 900° C. and about 1300° C. CVI may be performed at relatively low pressure and may use multiple cycles in the furnace. Silicon carbide may also be deposited to build up one or more layers on the fibers while the preform is in the furnace. The silicon carbide may provide additional protection to the fibers and may also increase the stiffness of the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  and the tip preform. In some embodiments, boron nitride may be deposited prior the silicon carbide to provide further beneficial mechanical properties to the fibers. 
         [0053]    The laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  may be taken out of the furnace after a first pass through the furnace and weighed. If the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  are not at a target weight they may go through the furnace for another run, which may occur as many times as necessary in order to achieve the target weight. The target weight may be determined by the final part to be made. CVI or CVD may form a preform with a porosity of between about 40% and about 60%. If the laid up reinforcement sheets  121 ,  122 ,  141 ,  142 ,  161 ,  162  are at the target weight the method  2000  may proceed. 
         [0054]    Upon rigidization, the laid up reinforcement sheets  121 ,  122 ,  141 ,  142  are machined in step  2130  to form green body slots  1013 ,  1015  in the green body subparts  1012 ,  1014  as shown in  FIG. 5 . Additionally, when rigidized, the laid up reinforcement sheets  161 ,  162  are machined in step  2130  to provide a round shape that characterizes the green body biscuit  1016 . 
         [0055]    A step  2200  of the method  2000  is assembling green bodies to be coinfiltrated as shown in  FIGS. 5 and 6 . Particularly, in step  2200 , the green body biscuit  1016  is inserted into a first slot  1013  of the first green body subpart  1012  and a second slot  1015  of the second green body subpart  1014  to create a green assembly  1010  with a green joint  1020  between the first green body subpart  1012  and the second green body subpart  1014 . 
         [0056]    In some embodiments, the biscuit  1016  may be fully processed (rigidized) prior to assembly in step  2200 . Such fully processed biscuits  1016  may be preferred when machining of the biscuits  1016  ahead of assembly is required. 
         [0057]    A step  2300  of the method  2000  is slurry infiltrating the green assembly  1010  as shown in  FIGS. 5 and 6 . Slurry infiltration in step  2300  may include infiltrating the green assembly  1010  with slurry. Dispersing the slurry throughout the green assembly  1010  may include immersing the preforms in the slurry composition. The slurry may include particles of carbon and optionally silicon carbide. The slurry may flow into the spaces, pores, or openings between the fibers of the green assembly  1010  such that the slurry particles may uniformly impregnate the pores of the green assembly  1010  and reside in the interstices between fibers of the green assembly  1010 . The slurry infiltration process may form a resultant matrix for the component with a porosity of between about 35% and about 50%. 
         [0058]    Prior to immersion, the fibers of the green assembly  1010  may optionally be prepared for slurry infiltration by exposing the fibers to a solution including, for example, water, solvents, surfactants and the like to aid impregnation of the fibers. Optionally, a vacuum may be drawn prior to slurry introduction to purge gas from the green assembly  1010  and further enhance impregnation. Slurry infiltration may be conducted at any suitable temperature such as at room temperature (about 20° C. to about 35° C.). The slurry infiltration may be enhanced by application of external pressure after slurry introduction such as at one atmosphere pressure gradient. 
         [0059]    A step  2400  of the method  2000  includes melt infiltration of the green assembly  1010  as shown in  FIGS. 5 and 6 . During melt infiltration a molten metal or alloy may wick between the openings of the green assembly  1010 . In various embodiments, the molten metal or alloy may have composition that includes silicon, boron, aluminum, yttrium, titanium, zirconium, oxides thereof, and mixtures and combinations thereof. In some instances, graphite powder may be added to assist the melt infiltration. The molten metal or alloy may wick into the remaining pores of the preform through capillary pressure. For example, molten silicon metal may wick into the pores and form silicon carbide to create a matrix between the fibers resulting in a relatively dense integrally joined component  10  compared to the green assembly  1010 . For example, after the green assembly  1010  has been densified, the integrally joined component  10  may have a porosity of between about 1 percent and about 10 percent by volume. 
         [0060]    In one example, a temperature for melt infiltration of silicon may be between about 1400° C. and about 1500° C. The duration of the melt infiltration may be between about 15 minutes and 4 hours. The melt infiltration process may optionally be carried out under vacuum, but in other embodiments melt infiltration may be carried out with an inert gas under atmospheric pressure to limit evaporation losses. The co-infiltration processes described herein may create the integrally joined component  10  in which the first subpart  12 , the second subpart  14 , and the biscuit  16  are a one-piece, continuous structure. 
         [0061]    A second integrally joined component  210  adapted for use in a gas turbine engine that may be made by method  1000  or  2000  is shown in  FIG. 7 . The component  210  illustratively comprises ceramic matrix composite materials and is made up of a first subpart  214 , a second subpart  214 , and a pair of biscuits  216 . The biscuits  216  extend into blind slots  213  formed in the first subpart  212  and into blind slots  215  formed in the second subpart  214  to form a joint  220 . The joint  220  is coinfiltrated with ceramic-containing matrix material to integrally join the first subpart  212 , the second subpart  214 , and the biscuit  216 . 
         [0062]    The first subpart  212 , the second subpart  214 , and the biscuits  216  are each made up of stacked sheets or plies of reinforcement material that are suspended in a ceramic matrix. In the illustrative embodiment, fibers of the stacked plies comprise silicon-carbide but may comprise other ceramic-containing materials or other non-ceramic materials. In other embodiments, one or more of the first subpart  212 , the second subpart  214 , and the biscuits  216  may comprise other configurations of reinforcement fibers suspended in a matrix, monolithic ceramic-containing materials, or other materials adapted for use in a gas turbine engine. 
         [0063]    In the illustrative embodiment, the biscuits  216  are round, disk-shaped components as shown in  FIG. 7 . The blind slots  213 ,  215  are shaped to receive substantially all of the biscuits  216  so that end faces  222 ,  224  of the first subpart  212  and the second subpart  214  face and engage one another in the illustrative component  210 . The biscuits  216  are spaced apart from an outer surface  225  of the component  210 . 
         [0064]    A third integrally joined component  310  adapted for use in a gas turbine engine that may be made by method  1000  or  2000  is shown in  FIG. 8 . The component  310  illustratively comprises ceramic matrix composite materials and is made up of a first subpart  314 , a second subpart  314 , and a pair of biscuits  316 . The biscuits  316  extend into blind slots  313  formed in the first subpart  312  and into blind slots  315  formed in the second subpart  314  to form a joint  320 . The joint  320  is coinfiltrated with ceramic-containing matrix material to integrally join the first subpart  312 , the second subpart  314 , and the biscuits  316 . 
         [0065]    The first subpart  312 , the second subpart  314 , and the biscuits  316  are each made up of stacked sheets or plies of reinforcement material that are suspended in a ceramic matrix. In the illustrative embodiment, fibers of the stacked plies comprise silicon-carbide but may comprise other ceramic-containing materials or other non-ceramic materials. In other embodiments, one or more of the first subpart  312 , the second subpart  314 , and the biscuits  316  may comprise other configurations of reinforcement fibers suspended in a matrix, monolithic ceramic-containing materials, or other materials adapted for use in a gas turbine engine. 
         [0066]    In the illustrative embodiment, the biscuits  316  are oblong, disk-shaped components as shown in  FIG. 8 . The blind slots  313 ,  315  are shaped to receive substantially all of the biscuits  316  so that end faces  322 ,  324  of the first subpart  312  and the second subpart  314  face and engage one another in the illustrative component  310 . The biscuits  316  are spaced apart from an outer surface  325  of the component  310 . 
         [0067]    A fourth integrally joined component  410  adapted for use in a gas turbine engine that may be made by method  1000  or  2000  is shown in  FIG. 9 . The component  410  illustratively comprises ceramic matrix composite materials and is made up of a first subpart  414 , a second subpart  414 , and a biscuit  416 . The biscuit  416  extends into a blind slot  413  formed in the first subpart  412  and into a blind slot  415  formed in the second subpart  414  to form a joint  420 . The joint  420  is coinfiltrated with ceramic-containing matrix material to integrally join the first subpart  412 , the second subpart  414 , and the biscuit  416 . 
         [0068]    The first subpart  412 , the second subpart  414 , and the biscuit  416  are each made up of stacked sheets or plies of reinforcement material that are suspended in a ceramic matrix. In the illustrative embodiment, fibers of the stacked plies comprise silicon-carbide but may comprise other ceramic-containing materials or other non-ceramic materials. In other embodiments, one or more of the first subpart  412 , the second subpart  414 , and the biscuits  416  may comprise other configurations of reinforcement fibers suspended in a matrix, monolithic ceramic-containing materials, or other materials adapted for use in a gas turbine engine. 
         [0069]    In the illustrative embodiment, the biscuit  416  is an oblong, disk-shaped component as shown in  FIG. 9 . The blind slots  413 ,  415  are shaped to receive substantially all of the biscuit  416  so that end faces  422 ,  424  of the first subpart  412  and the second subpart  414  face and engage one another in the illustrative component  410 . The biscuit  416  is spaced apart from an outer surface  425  of the component  410 . 
         [0070]    A fifth integrally joined component  510  adapted for use in a gas turbine engine that may be made by method  1000  or  2000  is shown in  FIG. 10 . The component  510  illustratively comprises ceramic matrix composite materials and is made up of a first subpart  514 , a second subpart  514 , and a pair of biscuits  516 . The biscuits  516  extend into blind slots  513  formed in the first subpart  512  and into blind slots  515  formed in the second subpart  514  to form a joint  520 . The joint  520  is coinfiltrated with ceramic-containing matrix material to integrally join the first subpart  512 , the second subpart  514 , and the biscuits  516 . 
         [0071]    The first subpart  512 , the second subpart  514 , and the biscuits  516  are each made up of stacked sheets or plies of reinforcement material that are suspended in a ceramic matrix. In the illustrative embodiment, fibers of the stacked plies comprise silicon-carbide but may comprise other ceramic-containing materials or other non-ceramic materials. In other embodiments, one or more of the first subpart  512 , the second subpart  514 , and the biscuits  516  may comprise other configurations of reinforcement fibers suspended in a matrix, monolithic ceramic-containing materials, or other materials adapted for use in a gas turbine engine. 
         [0072]    In the illustrative embodiment, the biscuits  516  are rectangular components as shown in  FIG. 10 . The blind slots  513 ,  515  are shaped to receive substantially all of the biscuits  516  so that end faces  522 ,  524  of the first subpart  512  and the second subpart  514  face and engage one another in the illustrative component  510 . The biscuits  516  are spaced apart from an outer surface  525  of the component  510 . 
         [0073]    A sixth integrally joined component  610  adapted for use in a gas turbine engine that may be made by method  1000  or  2000  is shown in  FIG. 11 . The component  610  illustratively comprises ceramic matrix composite materials and is made up of a first subpart  614 , a second subpart  614 , and a biscuit  616 . The biscuit  616  extends into a slot  613  formed in the first subpart  612  and into a slot  615  formed in the second subpart  614  to form a joint  620 . The joint  620  is coinfiltrated with ceramic-containing matrix material to integrally join the first subpart  612 , the second subpart  614 , and the biscuit  616 . 
         [0074]    The first subpart  612 , the second subpart  614 , and the biscuit  616  are each made up of stacked sheets or plies of reinforcement material that are suspended in a ceramic matrix. In the illustrative embodiment, fibers of the stacked plies comprise silicon-carbide but may comprise other ceramic-containing materials or other non-ceramic materials. In other embodiments, one or more of the first subpart  612 , the second subpart  614 , and the biscuit  616  may comprise other configurations of reinforcement fibers suspended in a matrix, monolithic ceramic-containing materials, or other materials adapted for use in a gas turbine engine. 
         [0075]    In the illustrative embodiment, the biscuit  616  is a rectangular component as shown in  FIG. 16 . The slots  613 ,  615  are shaped to receive substantially all of the biscuits  616  so that end faces  622 ,  624  of the first subpart  612  and the second subpart  614  face and engage one another in the illustrative component  610 . The biscuit  616  illustratively forms a portion of an outer surface  625  of the component  610 . 
         [0076]    A seventh integrally joined component  710  adapted for use in a gas turbine engine that may be made by method  1000  or  2000  is shown in  FIG. 12 . The component  710  illustratively comprises ceramic matrix composite materials and is made up of a first subpart  714 , a second subpart  714 , and a biscuit  716 . The biscuit  716  extends into a blind slot  713  formed in the first subpart  712  and into a blind slot  715  formed in the second subpart  714  to form a joint  720 . The joint  720  is coinfiltrated with ceramic-containing matrix material to integrally join the first subpart  712 , the second subpart  714 , and the biscuit  716 . 
         [0077]    The first subpart  712 , the second subpart  714 , and the biscuits  716  are each made up of stacked sheets or plies of reinforcement material that are suspended in a ceramic matrix. In the illustrative embodiment, fibers of the stacked plies comprise silicon-carbide but may comprise other ceramic-containing materials or other non-ceramic materials. In other embodiments, one or more of the first subpart  712 , the second subpart  714 , and the biscuit  716  may comprise other configurations of reinforcement fibers suspended in a matrix, monolithic ceramic-containing materials, or other materials adapted for use in a gas turbine engine. 
         [0078]    In the illustrative embodiment, the biscuit  716  is a diamond shaped component as shown in  FIG. 12 . The blind slots  713 ,  715  are shaped to receive substantially all of the biscuit  716  so that end faces  722 ,  724  of the first subpart  712  and the second subpart  714  face and engage one another in the illustrative component  710 . The biscuit  716  is spaced apart from an outer surface  725  of the component  710 . 
         [0079]    According to the present disclosure, two or more silicon-carbide (SiC) fiber preforms with protective CVI can be joined with a third preform, or “biscuit”, using the same slurry infiltration and subsequent melt infiltration as a single component. This may provide robust, simple, individual components that can be joined to make more robust complex components. 
         [0080]    The general process flows shown in  FIGS. 3-6  of how the presently disclosed methods work provide two different paths with the first forming the general joint geometry in fiber layup and the other forming the general joint geometry with a machining process after CVI. Both form a joined component after the parts have been infiltrated with slurry and subsequently infiltrated with a molten medium (usually Si metal alloy). 
         [0081]    Another aspect of the integral joining method taught in this disclosure is that a simple butt joint can be avoided to provide mechanical robustness. Illustratively, in the disclosed embodiments a third piece, or “biscuit”, of different geometries is placed interlaminarly into two other components before slurry and melt infiltration is used to consolidate the part. A separate, or third, piece provides a joint that does not extend completely through a thickness of the resulting part and may give better interlaminar mechanical capability. 
         [0082]    While the disclosure has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.