The present invention relates to a metal oxide coated composite comprising a core consisting of a mixture of a La stabilised AI.sub.2O.sub.3 phase and an Ce/Zr/RE.sub.2O.sub.3 mixed oxide phase, the core having a specific crystallinity, specific pore volume and a specific pore size distribution, and a method for the production of the metal oxide coated composite.

A blade outer air seal has at least one internal surface and a layer atop the at least one internal surface. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and zirconium silicate (ZrSiO.sub.4), ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS) or other alkaline earth aluminosilicate.

A blade outer air seal has at least one internal surface and a layer atop the at least one internal surface. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and zirconium silicate (ZrSiO.sub.4), ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS) or other alkaline earth aluminosilicate.

An automated preparation method of a SiC.sub.f/SiC composite flame tube, comprising the following steps: preparing an interface layer for a SiC fiber by a chemical vapor infiltration process, and obtaining the SiC fiber with a continuous interface layer; laying a unidirectional tape on the SiC fiber with the continuous interface layer and winding the SiC fiber with the continuous interface layer to form and obtaining a preform of a net size molding according to a fiber volume and a fiber orientation obtained in a simulation calculation; and adopting a reactive melt infiltration process and the chemical vapor infiltration process successively for a densification and obtaining a high-density SiC.sub.f/SiC composite flame tube in a full intelligent way. The SiC.sub.f/SiC composite flame tube prepared by the present disclosure not only has a high temperature resistance, but also has a low thermal expansion coefficient, high thermal conductivity and high thermal shock resistance.

A porous body is provided with enhanced fluid transport properties that is capable of performing or facilitating separations, or performing reactions and/or providing areas for such separations or reactions to take place. The porous body includes at least 80 percent alpha alumina and has a pore volume from 0.3 mL/g to 1.2 mL/g and a surface area from 0.3 m.sup.2/g to 3.0 m.sup.2/g. The porous body further includes a pore architecture that provides at least one of a tortuosity of 7.0 or less, a constriction of 4.0 or less and a permeability of 30 mdarcys or greater. The porous body can be used in a wide variety of applications such as, for example, as a filter, as a membrane or as a catalyst carrier.

A porous body is provided with enhanced fluid transport properties that is capable of performing or facilitating separations, or performing reactions and/or providing areas for such separations or reactions to take place. The porous body includes at least 80 percent alpha alumina and has a pore volume from 0.3 mL/g to 1.2 mL/g and a surface area from 0.3 m.sup.2/g to 3.0 m.sup.2/g. The porous body further includes a pore architecture that provides at least one of a tortuosity of 7.0 or less, a constriction of 4.0 or less and a permeability of 30 mdarcys or greater. The porous body can be used in a wide variety of applications such as, for example, as a filter, as a membrane or as a catalyst carrier.

A method includes feeding at least one ceramic feedstock into a heating zone of a thermal spray apparatus to form a heated ceramic feedstock. The heated ceramic feedstock is entrained in a plasma gas to form a heated gas stream directed toward a target surface of a CMC substrate. A sacrificial composition is fed with a sacrificial composition feed apparatus into the heated gas stream downstream of the heating zone at a selected injection angle α of about −30° to about +30° with respect to a plane of the target surface of the substrate. The heated ceramic feedstock is deposited from the heated gas stream onto the target surface to form a coating thereon. The thermal spray apparatus and the sacrificial composition feed system are configured to independently control a chemistry and a porosity of the coating.

A method includes feeding at least one ceramic feedstock into a heating zone of a thermal spray apparatus to form a heated ceramic feedstock. The heated ceramic feedstock is entrained in a plasma gas to form a heated gas stream directed toward a target surface of a CMC substrate. A sacrificial composition is fed with a sacrificial composition feed apparatus into the heated gas stream downstream of the heating zone at a selected injection angle α of about −30° to about +30° with respect to a plane of the target surface of the substrate. The heated ceramic feedstock is deposited from the heated gas stream onto the target surface to form a coating thereon. The thermal spray apparatus and the sacrificial composition feed system are configured to independently control a chemistry and a porosity of the coating.

A porous discriminating layer is formed on a ceramic support having at least one porous wall by (a) establishing a flow of a gas stream containing agglomerates of particles and (b) calcining said deposited layer to form the discriminating layer. At least a portion of the particles are of a sinter-resistant material or a sinter-resistant material precursor. The particles have a size from 0.01 to 5 microns and the agglomerates have a size of from 10 to 200 microns. This method is an inexpensive and effective route to forming a discriminating layer onto the porous wall.

A porous discriminating layer is formed on a ceramic support having at least one porous wall by (a) establishing a flow of a gas stream containing agglomerates of particles and (b) calcining said deposited layer to form the discriminating layer. At least a portion of the particles are of a sinter-resistant material or a sinter-resistant material precursor. The particles have a size from 0.01 to 5 microns and the agglomerates have a size of from 10 to 200 microns. This method is an inexpensive and effective route to forming a discriminating layer onto the porous wall.