Green ceramic mixture for extruding into an extruded green body includes one or more inorganic components selected from the group consisting of ceramic ingredients, inorganic ceramic-forming ingredients, and combinations thereof, at least one mineral oil, and from about 0.01 wt % to about 0.45 wt % of an antioxidant based on a total weight of the inorganic component(s), by super addition. The mineral oil has a kinematic viscosity of ≥about 1.9 cSt at 100° C. The at least one antioxidant may have a degradation-rate peak temperature that is greater than the degradation-rate peak temperature of the at least one mineral oil. In some embodiments, the at least one mineral oil includes greater than about 20 wt % alkanes with greater than 20 carbons, based on a total weight of the at least one mineral oil. Methods of making an unfired extruded body using the batch mixture are also disclosed.

An oxidation protection system disposed on a substrate is provided, which may comprise a base layer comprising a first pre-slurry composition comprising a first phosphate glass composition, and/or a sealing layer comprising a second pre-slurry composition comprising a second phosphate glass composition and a strengthening compound comprising boron nitride, a metal oxide, and/or silicon carbide.

A corrosion-resistant ceramic of the present disclosure contains aluminum oxide as a main component and a yttrium-aluminum composite oxide as a secondary component, and includes a plurality of open pores. When an average value of inter-centroid distances between adjacent open pores is denoted by L1, L1 is 50 μm or greater.

A porous material includes aggregate particles and a binding material. In the aggregate particles, oxide films containing cristobalite are provided on surfaces of particle bodies that are silicon carbide particles or silicon nitride particles. The binding material binds the aggregate particles together in a state where pores are provided therein. The porous material contains at least one of copper, calcium, and nickel as an ancillary component.

Certain embodiments of the present disclosure relate to ceramic materials with high thermal shock resistance and high erosion resistance. In one embodiment, a ceramic material is formed from a composition comprising Al.sub.2O.sub.3, MgO, SiO.sub.2.

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.

Systems and methods for forming an oxidation protection system on a composite structure are provided. In various embodiments, the oxidation protection system comprises a boron-glass layer formed on the composite substrate and a silicon-glass layer formed over the boron-glass layer. Each of the boron-glass layer and the silicon-glass layer include a glass former and a glass modifier.

The present disclosure relates to an oxidation-induced shape memory fiber comprising a tension-bearing core material and/or a tension-bearing core material coated with an antioxidative coating, and an oxidizable pressure-bearing coating. The oxidizable pressure-bearing coating is coated outside the tension-bearing core material and/or the tension-bearing core material coated with an antioxidative coating; the oxidizable pressure-bearing coating is in compressive stress state and/or the tension-bearing core material coated with an antioxidative coating and the oxidizable pressure-bearing coating are in tension-compression balance state. The disclosure also relates to preparation and application thereof, the preparation is: reserving anchoring end, exerting tension force on tension-bearing core material and/or tension-bearing core material coated with an antioxidative coating, followed by coating oxidizable pressure-bearing coating thereon. The oxidation-induced shape memory fiber is applicable to high temperature oxidation environment.

A long-term ablation-resistant nitrogen-containing carbide ultra-high temperature ceramic with an ultra-high melting point is prepared as follows: preparing the HfC powder and the HfN powder according to a mass ratio of HfC:HfN=(1-7):1; uniformly mixing the HfC powder and the HfN powder with the carbon powder and the carbon nitride powder to obtain a mixed powder, wherein the amount of the carbon powder and the amount of the carbon nitride powder do not exceed 8.0 wt. % and 5.0 wt. %, respectively, of the mixed powder mass; and performing spark plasma sintering on the mixed powder to produce the ceramic with the ultra-high melting point, a density ≥98%, and a uniform C/N content distribution. The ultra-high temperature ceramic is suitable for ultra-high temperature ablation-resistant protection at ≥3000° C. The ceramic maintains a close to zero ablation rate and a continuously stable oxidation-resistant protective structure after ablation for 300 s.

A method of manufacturing a coated reinforcing fiber for use in Ceramic Matrix Composites, the method comprising pre-oxidizing a plurality of silicon-based fibers selected from the group consisting of silicon carbide (SiC) fibers, silicon nitride (Si.sub.3N.sub.4) fibers, SiCO fibers, SiCN fibers, SiCNO fibers, and SiBCN fibers at between 700 to 1300 degrees Celsius in an oxidizing atmosphere to form a silica surface layer on the plurality of silicon-based fibers, forming a plurality of pre-oxidized fibers; applying a rare earth orthophosphate (REPO.sub.4) coating to the plurality of pre-oxidized fibers; and heating the plurality of REPO.sub.4 coated pre-oxidized fibers at about 1000-1500 degrees Celsius in an inert atmosphere to react the REPO.sub.4 with the silica surface layer to form a rare earth silicate or disilicate. The pre-oxidizing step may be 0.5 hours to about 100 hours. The heating step may be about 5 minutes to about 100 hours.