A gas turbine engine article includes a substrate and an environmental barrier coating (EBC) system disposed on the substrate. The EBC system includes, from the substrate, a dense bond coat layer, a porous bond coat layer, and a topcoat layer in contact with the porous bond coat layer at an interface. The porous bond coat layer includes a matrix, oxygen-scavenging gas-evolution particles dispersed through the matrix, and engineered buffer pores. The oxygen-scavenging gas-evolution particles react with oxygen and generate a gaseous byproduct that diffuses through the interface to escape the EBC system. The engineered buffer pores buffer diffusion of gaseous byproduct to the interface by retaining at least a portion of the gaseous byproduct.

A heat-resistant member includes a base member composed of an isotropic graphite and a film with a single layer or multiple layers formed on the entire or partial surface of the base member. The film includes a dense WC layer with a single layer or multiple layers, and the dense WC layer includes WC as a main component and has a porosity of less than 3%. The film may further include a porous WC layer with a single layer or multiple layers formed on an entire or partial surface of the dense WC layer. In this case, the porous WC layer preferably includes WC as a main component and has a porosity larger than that of the dense WC layer.

A heat-resistant member includes a base member composed of an isotropic graphite and a film with a single layer or multiple layers formed on the entire or partial surface of the base member. The film includes a dense WC layer with a single layer or multiple layers, and the dense WC layer includes WC as a main component and has a porosity of less than 3%. The film may further include a porous WC layer with a single layer or multiple layers formed on an entire or partial surface of the dense WC layer. In this case, the porous WC layer preferably includes WC as a main component and has a porosity larger than that of the dense WC layer.

A method includes depositing a porous silicon coat on a substrate to form a bulk phase of a bond coat and introducing a reactive gas into pores of the porous silicon coat. The reactive gas reacts with silicon adjacent the pores of the porous silicon coat to form a ceramic phase of the bond coat comprising a silicon-based ceramic and reduce porosity of the porous silicon coat. A temperature of the reactive gas is greater than about 1000° C.

A method includes depositing a porous silicon coat on a substrate to form a bulk phase of a bond coat and introducing a reactive gas into pores of the porous silicon coat. The reactive gas reacts with silicon adjacent the pores of the porous silicon coat to form a ceramic phase of the bond coat comprising a silicon-based ceramic and reduce porosity of the porous silicon coat. A temperature of the reactive gas is greater than about 1000° C.

Disclosed is a multi-phase abradable coating including a ceramic matrix and a dislocator phase.

Disclosed is a multi-phase abradable coating including a ceramic matrix and a dislocator phase.

A heat-resistant member includes a base member composed of an isotropic graphite and a film with a single layer or multiple layers formed on the entire or partial surface of the base member. The film includes a dense WC layer with a single layer or multiple layers, and the dense WC layer includes WC as a main component and has a porosity of less than 3%. The film may further include a porous WC layer with a single layer or multiple layers formed on an entire or partial surface of the dense WC layer. In this case, the porous WC layer preferably includes WC as a main component and has a porosity larger than that of the dense WC layer.

A heat-resistant member includes a base member composed of an isotropic graphite and a film with a single layer or multiple layers formed on the entire or partial surface of the base member. The film includes a dense WC layer with a single layer or multiple layers, and the dense WC layer includes WC as a main component and has a porosity of less than 3%. The film may further include a porous WC layer with a single layer or multiple layers formed on an entire or partial surface of the dense WC layer. In this case, the porous WC layer preferably includes WC as a main component and has a porosity larger than that of the dense WC layer.

A porous refractory in the K.sub.2O—SiO.sub.2—B.sub.2O.sub.3 system is formed by chemical direct foaming by heating to over 600° C., resulting in adherent black or white foam. The foam can function as highly porous thermal insulation, a high or low thermal emissivity surface, as a sealant for deteriorated refractory surfaces, as a filler for pockmarks/holes/gaps or as a bonding agent for parts with large gaps between them.