Abstract: A system and method of melt infiltrating components is provided. In one example aspect, an inductive heating system includes a heating source that inductively heats a susceptor. The susceptor defines a working chamber in which components can be received. During melt infiltration, the system can heat the susceptor and thus the components and melt infiltrants disposed within the working chamber at a first heating rate. The first heating rate can be faster than 50° C./minute. The system can then heat the components and melt infiltrants at a second heating rate. The first heating rate is faster than the second heating rate. Thereafter, the system can heat the components and infiltrants at a third heating rate. The third heating rate can be a constant rate at or above the melting point of the melt infiltrants. The infiltrants can melt and thus infiltrate into the component to densify the component.

Abstract: A system and method of melt infiltrating components is provided. In one example aspect, an inductive heating system includes a heating source that inductively heats a susceptor. The susceptor defines a working chamber in which components can be received. During melt infiltration, the system can heat the susceptor and thus the components and melt infiltrants disposed within the working chamber at a first heating rate. The first heating rate can be faster than 50° C./minute. The system can then heat the components and melt infiltrants at a second heating rate. The first heating rate is faster than the second heating rate. Thereafter, the system can heat the components and infiltrants at a third heating rate. The third heating rate can be a constant rate at or above the melting point of the melt infiltrants. The infiltrants can melt and thus infiltrate into the component to densify the component.

Abstract: A process for producing an internal cavity in a CMC article and mandrels used therewith. The process entails incorporating a mandrel made of a material that is substantially absorbed during thermal treatment of a preform to form the CMC article. The mandrel material is preferably reactive with one or more constituents of the CMC preform during the thermal treatment. The material is preferably silicon or a silicon alloy.

Abstract: A process for producing an internal cavity in a CMC article and mandrels used therewith. The process entails incorporating a mandrel made of a fusible material that is melted and drained during a thermal treatment of a CMC preform to form the CMC article. The mandrel material is preferably non-wetting and non-reactive with any constituents of the CMC preform during the thermal treatment. The mandrel is preferably tin or an alloy of tin.

Abstract: Systems, methods and devices adapted to ease manufacture of composite articles (e.g., ceramic composite articles), particularly composite articles which include a hollow feature are disclosed. In one embodiment, a system includes: a consumable core formed to be disposed within an inner portion of a composite precursor, the consumable core adapted to convert into an infiltrant during a manufacturing process and infiltrate the composite precursor.

Abstract: A process for producing CMC articles that includes reducing the presence of porosity and voids within the articles. The process is performed on a porous fired preform comprising a fiber reinforcement material and a ceramic matrix material, and the preform is densified by heating the preform and a fill material to melt the fill material, and by creating a vacuum that causes the molten fill material to infiltrate and partially fill voids within the preform. While the fill material remains molten within the voids, the preform and fill material are subjected to an increased pressure to further fill the voids with the molten fill material. Thereafter, and while the preform and molten fill material therein remain subject to the increased pressure, the preform and fill material are cooled to solidify the fill material within the voids and yield a CMC article.

Abstract: Methods for repairing a turbine airfoil constructed from a CMC material are provided via filling a cavity located in the turbine airfoil with a ceramic paste (e.g., including a ceramic powder and a binder), heating the ceramic paste in the cavity to remove the binder, thereby forming a porous ceramic material, and adding a molten ceramic material to the porous ceramic material. The cavity can be defined in an airfoil of the turbine airfoil (e.g., on a tip or cap of the airfoil). Intermediates formed during the repair of a turbine airfoil are also provided. The intermediate can generally include an airfoil comprising a CMC material, a cavity defined in the airfoil, and a porous ceramic material filling the cavity.

Abstract: In certain embodiments of the present disclosure a method for modifying a composite article is described. The method includes positioning a plug made from composite material at a site on the composite article. The method further includes rotating at least one of the plug and the article at a rate of speed sufficient to form an inertia bond between the plug and the site of the composite article. The plug and the site are engaged to effect an inertia bond therebetween.

Abstract: Systems, methods and devices adapted to ease manufacture of composite articles (e.g., ceramic composite articles), particularly composite articles which include a hollow feature are disclosed. In one embodiment, a system includes: a consumable core formed to be disposed within an inner portion of a composite precursor, the consumable core adapted to convert into an infiltrant during a manufacturing process and infiltrate the composite precursor.

Abstract: A process for producing an internal cavity in a CMC article and mandrels used therewith. The process entails incorporating a mandrel made of a fusible material that is melted and drained during a thermal treatment of a CMC preform to form the CMC article. The mandrel material is preferably non-wetting and non-reactive with any constituents of the CMC preform during the thermal treatment. The mandrel is preferably tin or an alloy of tin.

Abstract: A process for producing silicon-containing CMC articles. The process entails producing a matrix slurry composition that contains at least one resin binder and a SiC powder. The SiC powder is a precursor for a SiC matrix of the CMC article and the resin binder is a precursor for a carbon char of the matrix. A fiber reinforcement material is impregnated with the slurry composition to yield a preform, which is then heated to form a porous preform that contains the SiC matrix and porosity and to convert the resin binder to the carbon char that is present within the porosity. Melt infiltration of the porosity is then performed with molten silicon or a molten silicon-containing alloy to react the carbon char and form silicon carbide that at least partially fills the porosity within the porous preform. The carbon char constitutes essentially all of the elemental carbon in the porous preform.

Abstract: In certain embodiments of the present disclosure a method for modifying a composite article is described. The method includes positioning a plug made from composite material at a site on the composite article. The method further includes rotating at least one of the plug and the article at a rate of speed sufficient to form an inertia bond between the plug and the site of the composite article. The plug and the site are engaged to effect an inertia bond therebetween.

Abstract: Methods for repairing a turbine airfoil constructed from a CMC material are provided via filling a cavity located in the turbine airfoil with a ceramic paste (e.g., including a ceramic powder and a binder), heating the ceramic paste in the cavity to remove the binder, thereby forming a porous ceramic material, and adding a molten ceramic material to the porous ceramic material. The cavity can be defined in an airfoil of the turbine airfoil (e.g., on a tip or cap of the airfoil). Intermediates formed during the repair of a turbine airfoil are also provided. The intermediate can generally include an airfoil comprising a CMC material, a cavity defined in the airfoil, and a porous ceramic material filling the cavity.

Abstract: A method of producing a CMC article having a net shape, and by which the article can be formed to have an exterior surface with desirable characteristics, such as being free of an imprint pattern of a fiber reinforcement material within the article. The method entails providing a body comprising the fiber reinforcement material, and depositing a coating on a surface of the body. The coating contains a carbonaceous binder and a slurry containing a ceramic particulate material. Following its deposition, the carbonaceous binder within the coating is cured to render the coating machinable, and the coating is then machined to approximately produce the net shape of the article.

Abstract: A method of manufacturing a carbon-based tooling for use as the support during melt infiltration processing of a prepreg preform used, for example, to manufacture turbine engine components, comprising forming an admixture of chopped carbon fibers, graphite powder and a high durometer thermosetting organic resin, applying a potion of the admixture at room temperature onto the surface of an aluminum die, initially curing the admixture as applied to the aluminum die for a period of 3-5 hours at a temperature of between about 100 and 200 degrees C., removing the carbon-based tooling from the aluminum die and carbonizing the tooling by heating the initially cured tooling to a temperature of about 750 degrees C for a period of about 40 hours.