Abstract: Disclosed herein are methods of forming substantially crystalline, dense silicon carbide fibers from infusible polysilazane fibers by utilizing a single stage pyrolysis. The pyrolysis is performed using a continuous process in a single furnace with a constant atmospheric condition. Also disclosed are substantially crystalline, dense silicon carbide fibers formed by these methods.

Abstract: Methods of producing low-halogen-containing polysilazane resins, which are used to make silicon carbide fibers and ceramic coatings, provide processes for removing halogens, including chlorine, from precursor polysilazane resins.

Abstract: Disclosed herein are methods of curing silicon carbide precursor polymer fibers, such as polysilazanes, using moisture and free radical generators, such as peroxides. Also disclosed are methods of forming, curing, and using silicon carbide precursor polymers that contain alkenyl groups and free radical generators, such as peroxides.

Abstract: Polymer-based materials and processes suitable for producing panels, for example, panels for use in a fan shroud abradable seal of a turbofan engine. Such a process includes introducing constituents of an expandable foam material into a continuous forming apparatus that continuously compounds the constituents into a partially-cured compounded polymeric material, which is then continuously formed with the continuous forming apparatus to produce a continuous form having a constant cross-sectional shape transverse to a continuous forming direction of the continuous forming apparatus. A portion of the continuous form is then deformed to produce a preform, and the preform is cured within a restricted volume to cause the preform to expand and produce the panel.

Abstract: The present disclosure generally provides methods and apparatus for efficiently crosslinking silicon carbide fiber precursor polymers with electron beam radiation. The methods and apparatus utilize a platform containing silicon carbide fiber precursor polymer. The temperature of the platform is regulated while the silicon carbide fiber precursor polymer is irradiated to thereby regulate the temperature of the irradiated silicon carbide fiber precursor polymer thereon. In this way, the temperature of the irradiated silicon carbide fiber precursor polymer is regulated via the platform both during and after it is subjected to radiation. At least one of the platform and the e-beam radiation mechanism may be translated with respect to the other to irradiate different portions of the silicon carbide fiber precursor polymer and, ultimately, the entirety of the silicon carbide fiber precursor polymer contained on the platform.

Abstract: The present disclosure generally relates to methods of using boron-containing additives for crosslinking polysilazane green fibers, which are precursors to silicon carbide fibers. These methods provide a controllable process for crosslinking silicon carbide fibers while providing a simple way for the introduction of boron as a sintering aid into the polymer structure.

Abstract: Disclosed herein are methods of curing silicon carbide precursor polymer fibers, such as polysilazanes, using moisture and free radical generators, such as peroxides. Also disclosed are methods of forming, curing, and using silicon carbide precursor polymers that contain alkenyl groups and free radical generators, such as peroxides.

Abstract: The present disclosure generally provides methods and apparatus for efficiently crosslinking silicon carbide fiber precursor polymers with electron beam radiation. The methods and apparatus utilize a platform containing silicon carbide fiber precursor polymer. The temperature of the platform is regulated while the silicon carbide fiber precursor polymer is irradiated to thereby regulate the temperature of the irradiated silicon carbide fiber precursor polymer thereon. In this way, the temperature of the irradiated silicon carbide fiber precursor polymer is regulated via the platform both during and after it is subjected to radiation. At least one of the platform and the e-beam radiation mechanism may be translated with respect to the other to irradiate different portions of the silicon carbide fiber precursor polymer and, ultimately, the entirety of the silicon carbide fiber precursor polymer contained on the platform.

Abstract: The present disclosure generally relates to methods of using boron-containing additives for crosslinking polysilazane green fibers, which are precursors to silicon carbide fibers. These methods provide a controllable process for crosslinking silicon carbide fibers while providing a simple way for the introduction of boron as a sintering aid into the polymer structure.

Abstract: Polymer-based materials and processes suitable for producing panels, for example, panels for use in a fan shroud abradable seal of a turbofan engine. Such a process includes introducing constituents of an expandable foam material into a continuous forming apparatus that continuously compounds the constituents into a partially-cured compounded polymeric material, which is then continuously formed with the continuous forming apparatus to produce a continuous form having a constant cross-sectional shape transverse to a continuous forming direction of the continuous forming apparatus. A portion of the continuous form is then deformed to produce a preform, and the preform is cured within a restricted volume to cause the preform to expand and produce the panel.

Abstract: In one example of a carrier for growing adherent cells, comprises one or more surfaces; and one or more relief features on one or more of the surfaces, wherein the carrier has a length at least about 0.2 mm, a width at least about 0.2 mm, and a height in a range from about 0.012 mm to 0.5 mm; and wherein each of the relief features has a height in a range from about 2 to 200 ?m, and width in a range from about 20 to 200 ?m.