The process obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications.

Process for making carbon foam

A process for producing a carbon foam heat sink is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications. The foam is encased and filled with a phase change material to provide a very efficient heat sink device.

Pitch-based carbon foam heat sink with phase change material

All three classes of fibre reinforced composite materials (polymer, metal and ceramic matrix) may be produced by flow of liquid matrix into the open spaces left within pores of a fibre preform. Even though several specific issues arise from the nature of each composite matrix class, governing phenomena apply to all infiltration processes, and include in particular: (i) capillary phenomena, (ii) transport phenomena, and (iii) the mechanics of potential fibre preform deformation. These phenomena and their governing laws are reviewed for the case of isothermal infiltration with no phase transformations. Four basic functional quantities, which need to be known to model the processes, are identified, and addressed in turn. The paper concludes with some examples of modelling methodologies and comparison with experimental data.

Infiltration processing of fibre reinforced composites: governing phenomena

A process for continuous composite coextrusion comprising: (a) forming first a material-laden composition comprising a thermoplastic polymer and at least about 40 volume % of a ceramic or metallic particulate in a manner such that the composition has a substantially cylindrical geometry and thus can be used as a substantially cylindrical feed rod; (b) forming a hole down the symmetrical axis of the feed rod; (c) inserting the start of a continuous spool of ceramic fiber, metal fiber or carbon fiber through the hole in the feed rod; (d) extruding the feed rod and spool simultaneously to form a continuous filament consisting of a green matrix material completely surrounding a dense fiber reinforcement and said filament having an average diameter that is less than the average diameter of the feed rod; and (e) depositing the continuous filament into a desired architecture which preferably is determined from specific loading conditions of the desired object and CAD design of the object to provide a green fiber reinforced composite object.

Continuous fiber reinforced composites and methods, apparatuses, and compositions for making the same

A composition includes a carbon nanotube (CNT)-infused carbon fiber material that includes a carbon fiber material of spoolable dimensions and carbon nanotubes (CNTs) infused to the carbon fiber material. The infused CNTs are uniform in length and uniform in distribution. The CNT infused carbon fiber material also includes a barrier coating conformally disposed about the carbon fiber material, while the CNTs are substantially free of the barrier coating. A continuous CNT infusion process includes: (a) functionalizing a carbon fiber material; (b) disposing a barrier coating on the functionalized carbon fiber material (c) disposing a carbon nanotube (CNT)-forming catalyst on the functionalized carbon fiber material; and (d) synthesizing carbon nanotubes, thereby forming a carbon nanotube-infused carbon fiber material.

Cnt-infused carbon fiber materials and process therefor

A method for repairing an article made of a fiber-reinforced ceramic matrix composite comprises attaching sections of a fiber-reinforced tape to the damaged area and then infiltrating the sections with the ceramic matrix or ceramic matrix precursor material. The material around the damaged area may be removed first to form a depression that is then filled with sections of the fiber-reinforced tape and further infiltrated with the ceramic matrix or ceramic matrix precursor material. The repaired article shows stress-strain curve similar to a defect-free article.

Method for repairing articles of ceramic composites

A method for producing shaped articles of ceramic composites provides a high degree of dimensional tolerance to these articles. A fiber preform is disposed on a surface of a stable formed support, a surface of which is formed with a plurality of indentations, such as grooves, slots, or channels. Precursors of ceramic matrix materials are provided to the fiber preform to infiltrate from both sides of the fiber preform. The infiltration is conducted under vacuum at a temperature not much greater than a melting point of the precursors. The melt-infiltrated composite article substantially retains its dimension and shape throughout the fabrication process.

Method for producing melt-infiltrated ceramic compositions using formed supports

A CMC article and process for producing the article to have a layer on its surface that protects a reinforcement material within the article from damage. The method entails providing a body containing a ceramic reinforcement material in a matrix material that contains a precursor of a ceramic matrix material. A fraction of the reinforcement material is present and possibly exposed at a surface of the body. The body surface is then provided with a surface layer formed of a slurry containing a particulate material but lacking the reinforcement material of the body. The body and surface layer are heated to form the article by converting the precursor within the body to form the ceramic matrix material in which the reinforcement material is contained, and by converting the surface layer to form the protective layer that covers any fraction of the reinforcement material exposed at the body surface.

Process of producing a ceramic matrix composite article and article formed thereby

In a method of coating a CMC fiber, a multiplicity of fiber tows aligned as a ribbon are simultaneously passed through a reactor and a flow of fiber coating reactant is passed though the reactor to coat the tow fibers. A coating system comprises a reactor chamber to accommodate a multiplicity of fiber tows passing along a path substantially parallel to a longitudinal axis of the chamber and a flow of fiber coating reactant and an aligning structure at an end of the chamber to maintain the multiplicity of fiber tows in a narrow, elongated ribbon configuration. An article comprises a multiplicity of fiber tows aligned in a longitudinal planar array in the form of a ribbon.

Method and reactor to coat fiber tows and article

A method for forming a porous carbonaceous preform comprises, forming a mixture comprised of up to about 50 volume percent of furfuryl alcohol or tetrahydrofurfuryl alcohol, about 1 to 10 volume percent of a nonionic polyethylene oxide polymer ranging in molecular weight from about 100,000 to 5,000,000, about 30 to 80 volume percent of a carbonaceous material, and the balance water. The mixture is cast to form a body, and heated to decompose the polymer and form the porous preform. A molding composition for carbonaceous material comprises, up to about 50 volume percent of furfuryl alcohol or tetrahydrofurfuryl alcohol, about 1 to 10 volume percent of a nonionic polyethylene oxide polymer ranging in molecular weight from about 100,000 to 5,000,000, about 30 to 80 volume percent of the carbonaceous material, and the balance water.

Henry Charles Mcguigan

Papers

Method for repairing articles of ceramic composites

Method for producing melt-infiltrated ceramic compositions using formed supports

Process of producing a ceramic matrix composite article and article formed thereby

Method and reactor to coat fiber tows and article

Method of forming a porous carbonaceous preform from a water-based slurry