Patent Description:
Ceramic matrix composite materials are composite materials that include a matrix including carbon reinforced with carbon fibers. Ceramic matrix composite components can be used in many high temperature applications. For example, the aerospace industry employs ceramic matrix composite components as friction materials for commercial and military aircraft, such as brake friction materials.

Some composite composites, such as some ceramic matrix composite brake discs that are used in the aerospace industry, may be manufactured from carbon fiber preforms that include layers of carbon fibers, which may be densified using, for example, chemical vapor deposition/chemical vapor infiltration (CVD/CVI), vacuum/pressure infiltration (VPI), or resin transfer molding (RTM), to infiltrate the fiber preform with carbon or carbon precursor material. <CIT> discloses a method of forming a ceramic matrix composite comprising providing carbon mats and stacking the mats.

In some examples, the disclosure describes techniques according to claim <NUM> for forming a ceramic matrix composite component that includes aligning a plurality of carbon preform segments in a staggered arrangement with each carbon preform segment of the plurality of carbon preform segments including a carbon body that includes at least one of a plurality of carbon fibers or a carbon foam, and a silicon-based mixture that includes silicon particles, The technique may include heating the staggered arrangement to react the silicon particles with the carbon body to bond the plurality of carbon preform segments together and form the ceramic matrix composite component.

The disclosure describes an assembly that includes a plurality of carbon preform segments aligned in a staggered arrangement such that directly adjacent carbon preform segments are in direct contact with one another, where with each of the plurality of carbon preform segments includes a carbon body that includes a plurality of carbon fibers or a carbon foam and a silicon-based mixture that includes silicon particle deposited on the carbon body.

In some examples, the disclosure describes a ceramic matrix composite component that includes a composite body defining a plurality of regions of carbon material reactively bonded together by a silicon-carbide material, where the plurality of regions of carbon material include a plurality of carbon fibers or a carbon foam and where the plurality of regions of carbon material are aligned in a staggered arrangement.

The present disclosure describes techniques for forming a carbon composite according to claim <NUM> using a plurality of carbon preforms segments/discrete units that are collectively stacked and arranged into a desired shape and reactively bonded together to form the carbon composite. Each of the described carbon preform segments may include a carbon foam or a plurality of carbon fibers in combination with a silicon-based mixture. The discrete carbon preform segments may be uniform or differently sized to allow the segments to be aligned and stacked in a desired arrangement to produce a desired shape (e.g., disc brake). The stacked arrangement may then be heated under optional compression to induce reaction bonding between the silicon of the silicon-based mixture and the carbon of the carbon foam or fibers to form silicon carbide (SiC) and bond the individual carbon preform segments together producing the carbon composite. In some examples, the individual carbon preform segments can provide a greater degree of control and variability regarding the physical architecture in the resultant carbon composite including, for example, the regional density within the ceramic matrix composite component, the fiber architecture such as the orientation and population, or the like.

<FIG> is a perspective view of an example ceramic matrix composite component <NUM> produced from a plurality of individual carbon preform segments. <FIG> are schematic top (<FIG>) and cross-sectional (<FIG> - cross-section taken along line A-A of <FIG>) views of an example single-tiered arrangement <NUM> of carbon preform segments 22a, 22b, 22c, 22d (collectively "carbon preform segments <NUM>") that may be used to form the carbon composite of <FIG>. As shown in <FIG>, carbon preform segments <NUM> are aligned in a staggered arrangement i.e., offset brick-and-mortar style pattern where the interfaces between carbon preform segments <NUM> do not form a grid pattern or continue linearly in both an x and y direction) to fulfil a desired template design such as disk brake template <NUM>.

Individual carbon preform segments <NUM> may be any suitable size and shape. For example, carbon preform segments <NUM> may be substantially square prism shaped (e.g., as shown in <FIG>), box/cubical in shaped (e.g., as shown in <FIG>), poly-prism shaped (e.g., triangular, rectangular, pentagon, hexagonal (e.g., as shown in <FIG>), or the like), or combinations thereof. In some examples, the size and shape of the carbon preform segments <NUM> may be set so that adjacent faces between the carbon preform segments <NUM> intimately contact one another to eliminate gaps between the carbon preform segments <NUM> and ensure sufficient bonding between adjacent segments. In some examples, carbon preform segments <NUM> may be uniformly sized so as to proved efficient stacking arrangements and interchangeability between the segments. In some examples, a combination of carbon preform segment sizes and shapes may be used to help reduce waste of modify the seam architecture within resultant ceramic matrix composite component <NUM> as describe further below. In some examples the relative size of each carbon preform segment <NUM> may be about <NUM> millimeters (mm) to about the total thickness of the ceramic matrix composite component <NUM> (e.g., about <NUM>) depending on the desired shape, number of rows, number of layers, and the like. For example, carbon preform segment <NUM> may include at least one surface that defines a length of about <NUM>.

In some examples, the exterior surfaces of carbon preform segments <NUM> may include one or more geometric alignment features. For example, one or more of the surfaces of carbon preform segments <NUM> may include structural features such as, corrugated surfaces, protrusions and recesses, or the like that match and pair with corresponding structural features of an adjacent carbon preform segments <NUM>. In some examples, the geometric alignment features may be interlocking or at least partially interlocking. The geometric alignment features may be used to provide a more robust stacking arrangement of carbon preform segments <NUM> to reduce the presence of gaps and ensure proper positioning of carbon preform segments <NUM> prior to bonding. Additionally or alternatively the geometric alignment features may provide greater structural integrity in resultant ceramic matrix composite component <NUM> by disrupting the continuity of bonding seam lines (i.e., a continuous line of two or more bond seams produced between the bonded carbon preform segments <NUM>) so that the resultant bond seams are non-linear or at least partially non-linear.

In some examples, carbon preform segments <NUM> may include carbon body formed <NUM> of a plurality of carbon fibers combined with a silicon-based mixture. For example, <FIG> is an enlargement of carbon preform segment 22d illustrating carbon body <NUM> composed of plurality of carbon fibers coated with a silicon-based mixture <NUM>. In some examples, the plurality of carbon fibers forming carbon body <NUM> may provide form of a carbon fiber preform made of carbon fibers or carbon precursor fibers that have been pyrolyzed into carbon fibers. Examples of suitable carbon precursor fiber materials may include, for example, polyacrylonitrile (PAN), oxidized polyacrylonitrile (O-PAN), cellulose fibers (e.g., rayon or lignin), pitch fibers, or the like. Fiber preforms are constructed with carbon precursor fibers may be subjected to an initial carbonization cycle to convert the carbon precursor fibers to carbon fibers prior to the application of the silicon-based mixture <NUM>.

In some examples, the carbon body <NUM> may include layers of carbon fibers bound together. For example, a plurality of carbon fibers may be combined into one or more layers of web fibers (e.g., randomly orient/entangled fibers), tow fibers, woven fibers, or combinations thereof that have been stacked and bound together. In some examples the fiber layers can be bound though via needling or punching some of the fibers across the different layers to mechanically bind the layers together thereby producing the fiber preforms used to form the individual carbon preform segments <NUM>. In some examples the fiber layers may include precursor carbon fibers that are carbonized after the layers are bound together.

In some examples, the carbon fibers forming carbon body <NUM> may be selectively oriented such that the majority of the carbon fibers are oriented in a desired direction. For example, as shown in <FIG>, the fibers forming carbon body <NUM> are generally aligned vertically with the page. In some examples, the orientation of the carbon fibers within each carbon body <NUM> can be used to provide a greater degree of variability and control in constructing the fiber architecture of ceramic matrix composite component <NUM> that could not be obtained using traditional preform constructions. For example, during the assembly of single-tiered arrangement <NUM>, majority of the carbon preform segments (e.g., carbon preform segments 22a, 22b, and 22d) may be arranged such that the plurality of carbon fibers forming the respective carbon bodies <NUM> generally align in the radial direction of brake disk template <NUM> while some of the segments (e.g., carbon preform segment 22c) may be arranged such that of the plurality of carbon fibers of the respective carbon body <NUM> generally align in the axial direction of brake disk template <NUM>. In some examples, the orientations of the carbon fibers within each carbon preform segment <NUM> can be used to tailor the mechanical or thermal properties of the resultant ceramic matrix composite component <NUM>. For example, the carbon fibers aligned in the radial direction of brake disk template <NUM> may impart greater breaking strength to the component while the carbon fibers aligned in the axial direction of brake disk template <NUM> may impart great shear strength. Additionally or alternatively, the orientation and length of the carbon fibers can behave as a thermal conduit transferring heat generated at the surface of the composite component <NUM> away from the surface to other desired locations.

The modular design of carbon preform segments <NUM> allows for a greater degree of control in tailoring the fiber architecture of ceramic matrix composite component <NUM> such that the composite component is be best suited for a particular application without requiring significant re-tooling expenses to modify and create a traditional carbon fiber preform.

In some examples, the respective fiber densities (e.g., number of fibers per unit volume) of carbon bodies <NUM> for carbon preform segments <NUM> may be substantially uniform to produce a ceramic matrix composite component <NUM> having a relatively uniform fiber density. In other examples, the fiber density of carbon preform segments <NUM> may be selectively varied to produce a ceramic matrix composite component <NUM> that includes a varied fiber density. Such a design flexibility may allow a designer to selectively increase the fiber density for specific regions of ceramic matrix composite component <NUM> to modify the strength characteristics of the selected regions.

In some examples, carbon body <NUM> may be composed of carbon foam coated with a silicon-based mixture <NUM>. The carbon foam may include a three-dimensional, cross-linked network of carbon material establishing a porous, foam carbon body <NUM>. The carbon foam may be produced using from pyrolysis of pitch in an inert environment. The extent of cross-linking of the pitch material prior to pyrolysis may be used to control the extent of foaming/porosity within carbon body <NUM>. The more cross-linking within the pitch material prior to pyrolysis, the less porosity created. In contrast to a preform made of carbon fibers, a preform of carbon foam may be considered a substantially continuous, linked network of carbon material.

In some examples, the respective carbon bodies <NUM> (e.g., carbon fibers or carbon foam) of each carbon preform segment <NUM> may be at least partially densified prior to being coated with the silicon-based mixture <NUM>. Any suitable densification technique may be used. For example, carbon body <NUM> can be initially densified using for example resin infiltration carbonization. Examples of suitable resin materials may include, for example, thermoset resins including, for example, furan, phenolic (e.g., diphenyletherformaldehyde), polyimide, or the like; thermoplastic resins including, for example, coal tar, petroleum, or synthetic pitch, polyetheretherketone (PEEK), polyethylenimine (PEI), polybenzimidazole (PBI), polyarylacetylene, or the like. In other examples, the carbon fiber preform can be initially densified using chemical vapor infiltration (CVI) or chemical vapor deposition (CVD) to achieve a carbon preform exhibiting a desired initial density. Suitable CVI/CVD materials may include methane mixed with other light alkanes or alkenes.

In some examples, the relative size of each carbon preform segment <NUM> may significantly reduce the time and expense needed to collectively densify the respective carbon bodies <NUM> within all carbon preform segments <NUM> compared to the time and expense needed to densify a singular carbon preform structure of comparable target size and shape (e.g., the size and shape of carbon preform segments <NUM> when stacked and arranged in the shape of ceramic matrix composite component <NUM>). For example, one particular challenge associated with densifying carbon preforms is delivering/forming a sufficient amount of carbon material into the center of a preform body. When using, for example, a CVI/CVD densification process the delivery parameters of the carbon material are usually depended on the surface area of the preform body (e.g., points on influx), sized of openings within the preform, and the distance the carbon material must travel to reach the center of the preform body. In some examples, the deposition/formation of carbon material within the surface regions of the preform body can inhibit the ability of additional carbon material to reach the center of the preform body resulting in a density gradient within perform body and limiting the amount by with the preform can be densified. Additionally or alternatively, the relatively lager distance that the carbon material must travel often correlates to larger processing times. Due to the relatively small size and shape of each carbon preform segment <NUM>, the distance that the carbon material must travel to reach the center of the preform segment <NUM> remains relatively small thereby reducing or avoiding several of the complications associated with densifying larger preform bodies. In some examples, the processing times to collectively densify carbon preform segments <NUM> may be reduced by as much as <NUM>/<NUM> of the normal processing time for a similarly sized carbon fiber preform.

The initial density of carbon preform segments <NUM> prior to being coated with the silicon-based mixture <NUM> may be any suitable amount and may depend in part on the desired application for ceramic matrix composite component <NUM>. In some examples, each carbon preform segment <NUM> may be initially densified to substantially the same extent to form a ceramic matrix composite component <NUM> having a substantially uniform density (e.g., uniform or nearly uniform density thought the body of ceramic matrix composite component <NUM>). In other examples, the individual carbon preform segments <NUM> may be densified to different extents. For example, carbon preform segments <NUM> towards interior regions of single-tiered arrangement <NUM> such as segment 22c or those segments closer to the inner diameter of brake disk template <NUM>, may be densified to a greater extent to provide greater strength to specific regions within the resultant body of ceramic matrix composite component <NUM>. In some examples involving multi-tiered arrangements (e.g., multi-tiered arrangement <NUM> of <FIG>), interior layers or tiers (e.g., layer 34b) of the arrangement may be densified to a greater extent than exterior layers or tiers (e.g., layers 34a and 34c) to help reduce the amount and duration of any post bonding densification cycles that are applied. In some examples, the density of carbon preform segments <NUM> prior to being coated with the silicon-based mixture <NUM> may be about <NUM> grams per cubic centimeter (g/cc) to about <NUM>/cc. In some examples, the density of carbon preform segments <NUM> prior to being coated with the silicon-based mixture <NUM> may be at least <NUM>/cc.

Carbon preform segments <NUM> include silicon-based mixture <NUM> applied to the underlying carbon body <NUM>. Silicon-based mixture <NUM> may include silicon particles in a carrier fluid. The silicon particles may be any suitable size to allow sufficient infiltration into at least the exterior surface regions of carbon preform segments <NUM>. In some examples, the silicon particles may be less than about <NUM>. For example, the silicon particles may have an average size of about <NUM>.

Silicon-based mixture <NUM> may include any suitable carrier fluid, including for example, distilled water, ethanol, hydrocarbons, and the like. In some examples, silicon-based mixture <NUM> may be initially prepared to include greater than about <NUM> percent weight by volume (% w/v), e.g., about <NUM> % w/v, of the silicon particles to volume of carrier fluid.

In some examples, silicon-based mixture <NUM> may include one or more additives. For example, silicon-based mixture <NUM> may include an adhesion promoter to assist with securing the silicon particles to the underlying carbon body <NUM> prior to undergoing reactive bonding and is substantially removed (e.g., burned) from carbon preform segments <NUM> during the reactive bonding process. Any suitable adhesion promoter may be used including, for example, ammonium alginate, agar, agarose, or the like. Additionally or alternatively, silicon-based mixture <NUM> may include one or more surfactants to aid in the transport of the silicon particles during the coating process. In some examples, the one or more additives may be present in an amount of about <NUM> % w/v, e.g. <NUM> % w/v, based on the volume of carrier fluid.

Silicon-based mixture <NUM> may be applied to the underlying carbon body <NUM> of carbon preform segments <NUM> using any suitable technique including for example, dip coating, slurry spraying, slip application, or the like. Once coated into the carbon body <NUM>, the carrier fluid of silicon-based mixture <NUM> may be substantially removed (e.g., removed or nearly removed) from carbon preform segments <NUM> prior to bonding the segments together. In some examples, the carrier fluid may be removed by drying carbon preform segments <NUM> using a heated gas. In other examples, the carrier fluid may be removed as part of reaction bonding process during the heating phase prior to the point of reacting the silicon and carbon.

Any suitable amount of silicon material may be added to carbon body <NUM>. In some examples, the silicon material may be added to achieve a coverage of about <NUM>/cm<NUM> of silicon particles on the respective bond surfaces of carbon preform segments <NUM> with a tolerance of about +<NUM>% to -<NUM>%. The total amount of silicon coverage will ultimately be based on the density and or porosity of carbon body <NUM> at the time of joining.

While <FIG> illustrate carbon preform segments <NUM> aligned as single-tiered arrangement <NUM>, in other examples, carbon preform segments <NUM> may be stacked and aligned to produce a multi-layer arrangement that includes at least two tiers (e.g., layers) of stacked carbon preform segments <NUM>. For example, <FIG> are schematic top (<FIG>) and cross-sectional (<FIG> taken along line B-B of <FIG>) views of an example multi-tiered arrangement <NUM> of carbon preform segments <NUM> that may be used to form carbon composite <NUM> of FIG. As illustrated in <FIG>, in some examples, the staggered arrangement of carbon preform segments <NUM> may be continue throughout multi-tiered stack <NUM> such that carbon preform segments <NUM> within the respective layers 34a, 34b, 34c are offset from carbon preform segments <NUM> of an adjacent layer. The staggered arrangement is used to help disperse the location of the seams between the carbon preform segments <NUM> throughout multi-tiered stack <NUM> so as to reduce the total number of continuous seam lines (i.e., a continuous line of two or more bond seams produced between the bonded carbon preform segments <NUM>) present within the stack that would otherwise occur in, for example, a standard grid arrangement. In some examples, dispersing the seams throughout multi-tiered stack <NUM> may increase the strength of the resultant component (e.g., ceramic matrix composite component <NUM>) by dispersing any mechanical stress exerted on the component through the body of the component rather than along a particular continuous seam line.

While <FIG> illustrates multi-tiered stack <NUM> including discrete layers 34a, 34b, 34b of carbon preform segments <NUM>, in some examples the carbon preform segments <NUM> may be sized and shaped such that the carbon preform segments <NUM> are staggered stacked in a vertical direction (e.g., up and down with the page). In such examples, multi-tiered stack <NUM> may lack the presence of discrete layers yet still contain multiple tiers of carbon preform segments <NUM> such that the height of multi-tiered stack <NUM> is greater than the height of an individual carbon preform segment <NUM>.

<FIG> provides another schematic top view of an example staggered arrangement <NUM> of carbon preform segments <NUM>, <NUM> that can be used to form ceramic matrix composite component <NUM>. Staggered arrangement <NUM> may be single-tiered or a multi-tiered arrangement. In some examples, staggered arrangement <NUM> may include a combination of both rectangular carbon preform segments <NUM> and square carbon preform segments <NUM>. In some examples, the combination of carbon preform segments <NUM>, <NUM> of different shapes and sizes can be interposed throughout staggered arrangement <NUM> to reduce the presence of continuous seam lines, disrupt or otherwise break up the continuity of such seam lines, or a combination thereof. Additionally or alternatively, the combination of carbon preform segments <NUM>, <NUM> of different shapes and sizes can be used so as to reduce the amount of waste (e.g., the body of carbon preform segments needing to be removed after bonding to shape ceramic matrix composite component <NUM> into a desired configuration.

<FIG> provides another schematic top view of an example staggered arrangement <NUM> of carbon preform segments <NUM> that can be used to form ceramic matrix composite component <NUM>. Staggered arrangement <NUM> may be single-tiered or a multi-tiered arrangement. In some examples, staggered arrangement <NUM> may include a plurality of carbon preform segments <NUM> in the shape of a multi-faceted prisms, such as pentagonal prisms, hexagonal prisms as shown in <FIG>, or the like. In some examples, the multi-faceted shape of carbon preform segments <NUM> may help reduce the amount of waste material generated after staggered arrangement <NUM> is bonded and shaped to disk brake template <NUM>. Additionally or alternatively, the multi-faceted shape of carbon preform segments <NUM> can help reduce, disrupt, and/or eliminate the presence of continuous seam lines in the resultant ceramic matrix composite component <NUM>.

Once the carbon preform segments have been stacked and arranged in any desired shape and pattern, the carbon preform segments may be heated to melt the silicon of silicon-based mixture <NUM> (e.g., heat to greater than about <NUM>) and induce reactive bonding between the silicon and the carbon within the carbon preform segments (e.g., carbon body <NUM>).

In some examples, the heating and reaction bonding may occur in a substantially oxygen-free environment (e.g., free of oxygen or containing trace amounts of oxygen) so as minimize the amount silicon material that undergoes oxidation during the reaction bonding or the presence of oxygen induced side reactions. In some examples, the substantially oxygen-free environment may be established by heating carbon preform segments under a partial vacuum. A partial vacuum may be preferable to a full vacuum so as to prevent the silicon from vaporizing upon melting. <FIG> shows a phase transition plot that illustrates an example boiling curve for silicon as a function of vapor pressure and temperature. Area <NUM> represents a pressure and temperature ranges, which may be suitable for inducing reactive bonding between the silicon and carbon materials. In some examples, the reaction may occur under a partial vacuum of about 1e-<NUM> Torr and a temperature of about <NUM>. In some examples, the substantially oxygen-free environment may also include one or more oxygen getters to further reduce the amount of oxygen present in the environment. In other examples, the substantially oxygen-free environment may be established using an inert gas including for example, nitrogen, argon, or the like.

The resultant ceramic matrix composite component <NUM> formed via reactively bonding the carbon preform segments together may include a carbon-carbon-silicon carbide composite structure having the presence of silicon carbide. For example, the reactively bonding the carbon preform segments may result in a ceramic matrix composite component that exhibits of brick-and-mortar composite body with defined regions of carbon material (e.g., the brick regions) and defined regions of silicon-carbide material (e.g., the mortar regions) corresponding to the reacted seams created by the silicon material reacting with carbon. In some examples, the presence of silicon carbide throughout the structure may modify one or more of the mechanical strength properties, tribological properties, or thermal properties of the resultant ceramic matrix composite component <NUM> compared to a comparable single-body preform that is infiltrated with molten silicon.

Any suitable number of layers and quantity of carbon preform segments <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be used to form ceramic matrix composite component <NUM>. In some examples, ceramic matrix composite component <NUM> may be formed from at least two tiers (e.g., layers) of carbon preform segments <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and include on the order of about <NUM> individual carbon preform segments <NUM>, <NUM>, <NUM>, <NUM>, <NUM> per layer (e.g., a two layer stack may include about <NUM> individual carbon preform segments).

The carbon preform segments and the resultant ceramic matrix composite component described herein can be formed using any suitable technique. <FIG> is a flow diagram of an example method of forming the carbon preform segments and ceramic matrix composite components described herein. While the techniques of <FIG> are described with concurrent reference to the conceptual diagram of <FIG>, in other examples, the techniques of <FIG> may be used to form other carbon preform segments and composite components, or the articles of <FIG> may be formed using a technique different than that described in <FIG>.

The technique of <FIG> includes forming a plurality of carbon bodies <NUM> (<NUM>), coating the plurality of carbon bodies <NUM> with a silicon-based mixture <NUM> to form a plurality of carbon preform segments (<NUM>), arranging the plurality of carbon preform segments <NUM> in a staggered arrangement (<NUM>), heating the plurality of carbon preform segments <NUM> to reactively bond the plurality of carbon preform segments <NUM> together to form a ceramic matrix composite component <NUM> (<NUM>), and applying CVI/CVD to the ceramic matrix composite component (<NUM>).

Carbon bodies <NUM> can be formed (<NUM>) using any suitable technique. As described above, the respective carbon bodies <NUM> of plurality of carbon preform segments <NUM>, may be formed from a plurality of carbon fibers, carbon precursor fibers that have undergone carbonization to form carbon fibers, or carbon foam that have been sized and shaped to form carbon body <NUM> of a respective carbon preform segment <NUM>. In some examples in which the carbon body <NUM> includes carbon fibers, the carbon fibers may be provided in any suitable arrangement. For examples, plurality of carbon fibers may be combined into one or more layers of web fibers (e.g., randomly orient/entangled fibers), tow fibers, woven fibers, or combinations thereof that have been stacked and bound (e.g., needled) together. In some examples, the carbon fibers may be selectively oriented such that the majority of carbon fibers within an individual carbon preform segment <NUM> are aligned in a desired direction.

In some examples, carbon bodies <NUM> may be at least partially densified prior to being coated with the silicon-based mixture <NUM>. As described above, any suitable densification technique may be used including, for example, resin infiltration carbonization, CVI, CVD, or similar densification process.

The technique of <FIG> includes coating carbon bodies <NUM> with a silicon-based mixture <NUM> (<NUM>). As described above, the silicon-based mixture may include silicon particles mixed in a carrier fluid such as distilled water, ethanol, hydrocarbons, or the like. In some examples, the silicon-based mixture may include one or more optional additives including, for example, adhesion promoters such as ammonium alginate, agar, agarose, or the like; surfactants; antioxidants; carbon source material; or the like.

In some examples, carbon preform segments <NUM> may be machined to a desired size and shape so as to provide sufficient alignment and stackability between the segments. In some examples, carbon preform segments <NUM> maybe have as relative size of about <NUM> to about <NUM>. In some examples, the carbon preform segments <NUM> maybe have as relative size of about <NUM> to about half the thickness of ceramic matrix composite component <NUM> (e.g., about <NUM>).

Once carbon bodies <NUM> are coated with silicon-based mixture <NUM> (<NUM>), carbon preform segments <NUM> may be arranged in a staggered arrangement (<NUM>) (e.g., single-tiered arrangement <NUM>, multi-tiered arrangement <NUM>, staggered arrangement <NUM>, <NUM>, or the like). The staggered arrangement as opposed to a grid-arrangement may reduce or disperse the presence of bonding seam lines within resultant ceramic matrix composite component <NUM>, which may help to more evenly distribute mechanical forces across the seams throughout ceramic matrix composite component <NUM>. In some examples, the staggered arrangement may include a single-tiered arrangement <NUM> or a multi-tiered arrangement <NUM>.

After alignment, carbon preform segments <NUM> may be heated to reactively bond the plurality of carbon preform segments <NUM> together to form a ceramic matrix composite component <NUM> (<NUM>). In some examples, carbon preform segments <NUM> may be uniformly heated to melt the silicon (e.g., greater than about <NUM>) and induce reaction between the silicon and carbon of carbon body <NUM> to produce silicon carbide (SiC). In some examples, the heating process may take place in a substantially oxygen-free environment including, for example, an inert gas environment (e.g., argon or nitrogen) or under partial vacuum (e.g., about 1e-<NUM> Torr). Optionally, one or more oxygen getters may be used to capture trace amounts of oxygen.

In some examples, carbon preform segments <NUM> may be mechanically compressed during the heating process to substantially eliminate (e.g., eliminate or nearly eliminate) the presence of any gaps along the bond seams within the staggered arrangement <NUM>, <NUM>, <NUM>, <NUM>. For example, carbon preform segments <NUM> may be placed in a circular clamp or springform that surround staggered arrangement <NUM> and applies radial pressure to carbon preform segments <NUM>. In some examples involving a multi-tiered arrangement <NUM>, an additional compressive force may be applied to the two major surfaces of the multi-tiered arrangement <NUM> to compress the layers (e.g., layers 34a, 34b, 34c) or tiers together.

Once bonded, the resultant ceramic matrix composite component <NUM> may be subsequently processed including, for example, machined in to a desired shape (e.g., brake disk), further densified by applying CVI/CVD to the ceramic matrix composite component (<NUM>), heat treated (e.g., graphitized at a temperature greater than about <NUM>), topically treated (e.g., antioxidant coatings or sealants applied topically), or the like.

Claim 1:
A method for forming a ceramic matrix composite component, the method comprising:
forming a layer comprising a plurality of carbon preform segments, wherein within the layer the plurality of carbon preform segments are aligned in a staggered two-dimensional arrangement,
wherein the plurality of carbon preform segments in the layer are aligned in the staggered arrangement to form an offset brick and mortar type pattern where interfaces between the plurality of carbon preform segments do not form a grid pattern or do not continue linearly in both an x-direction and a y-direction across the layer of carbon preform segment
wherein each carbon preform segment of the plurality of carbon preform segments comprises:
a carbon body comprising at least one of a plurality of carbon fibers or a carbon foam, and
a silicon-based mixture comprising silicon particles; and
heating the layer of carbon preform segments to react the silicon particles with the carbon body to bond the plurality of carbon preform segments together and form the ceramic matrix composite component.