Solid or liquid N—H free, C-free, and Si-rich perhydropolysilazane compositions comprising units having the following formula [—N(SiH.sub.3).sub.x(SiH.sub.2—).sub.y], wherein x=0, 1, or 2 and y=0, 1, or 2 when x+y=2; and x=0, 1 or 2 and y=1, 2, or 3 when x+y=3 are disclosed. Also disclosed are synthesis methods and applications for the same.

A method may include depositing a sacrificial support material on or adjacent to a build surface. The sacrificial support material may be configured to support a continuous reinforcement material during an additive manufacturing technique. The method also may include extruding the continuous reinforcement material from an additive manufacturing device such that at least a portion of the continuous reinforcement material contacts and is supported by the sacrificial support material; and removing the sacrificial support material to result in a feature defined at least in part by the continuous reinforcement material at the absence of sacrificial support material.

Methods and ceramic matrix composite articles formed thereby, as well as systems for making such ceramic matrix composite articles and carrying out such methods are disclosed herein. The methods include preparing a ceramic matrix composite by steps including (a) providing reinforcing fiber, such as carbon fiber, for impregnation; (b) heat treating the reinforcing fiber; (c) impregnating the heat treated reinforcing fiber with a composition comprising a ceramic forming polymer to form a fiber reinforced, ceramic forming polymer pre-preg; and (d) heat molding the fiber reinforced, ceramic forming polymer pre-preg to form a molded ceramic matrix composite article.

A ceramic article includes a ceramic matrix composite that has a porous reinforcement structure and a ceramic matrix within pores of the porous reinforcement structure. The ceramic matrix composite includes a surface zone comprised of an exterior surface of the ceramic matrix composite and pores that extend from the exterior surface into the ceramic matrix composite. A glaze material seals the surface zone within the pores of the surface zone and on the exterior surface of the surface zone as an exterior glaze layer on the ceramic matrix composite. The glaze material is a glass or glass-ceramic material. The ceramic matrix composite includes an interior zone under the surface zone, and the interior zone is free of any of the glaze material and has a greater porosity than the surface zone.

A ceramic article includes a ceramic matrix composite that has a porous reinforcement structure and a ceramic matrix within pores of the porous reinforcement structure. The ceramic matrix composite includes a surface zone comprised of an exterior surface of the ceramic matrix composite and pores that extend from the exterior surface into the ceramic matrix composite. A glaze material seals the surface zone within the pores of the surface zone and on the exterior surface of the surface zone as an exterior glaze layer on the ceramic matrix composite. The glaze material is a glass or glass-ceramic material. The ceramic matrix composite includes an interior zone under the surface zone, and the interior zone is free of any of the glaze material and has a greater porosity than the surface zone.

Hybrid composite materials including carbon nanotube sheets and flexible ceramic materials, and methods of making the same are provided herein. In one embodiment, a method of forming a hybrid composite material is provided, the method including: placing a layer of a first flexible ceramic composite on a lay-up tooling surface; applying a sheet of a pre-preg carbon fiber reinforced polymer on the flexible ceramic composite; curing the flexible ceramic composite and the pre-preg carbon fiber reinforced polymer sheet together to form a hybrid composite material; and removing the hybrid composite material from the lay-up tooling surface, wherein the first flexible ceramic composite comprises an exterior surface of the hybrid composite material.

Hybrid composite materials including carbon nanotube sheets and flexible ceramic materials, and methods of making the same are provided herein. In one embodiment, a method of forming a hybrid composite material is provided, the method including: placing a layer of a first flexible ceramic composite on a lay-up tooling surface; applying a sheet of a pre-preg carbon fiber reinforced polymer on the flexible ceramic composite; curing the flexible ceramic composite and the pre-preg carbon fiber reinforced polymer sheet together to form a hybrid composite material; and removing the hybrid composite material from the lay-up tooling surface, wherein the first flexible ceramic composite comprises an exterior surface of the hybrid composite material.

The present disclosure provides for ceramic composite materials and methods of making ceramic composite materials. In an aspect, the ceramic composite materials can be made of polymer derived ceramics (PDCs) as the matrix, while substrates can be used as the microwave absorbing phases.

The present disclosure provides for ceramic composite materials and methods of making ceramic composite materials. In an aspect, the ceramic composite materials can be made of polymer derived ceramics (PDCs) as the matrix, while substrates can be used as the microwave absorbing phases.

A method for manufacturing a part made of composite material in which an adhesion promoter is grafted to a coating present on the fibre surface as well as to a ceramic precursor resin. Afterwards, a ceramic matrix phase is formed in the porosity of the fibre preform by pyrolysis of the polymerised resin.