Abstract: A treated refractory material includes a refractory material having a plurality of pores, wherein the refractory material comprises aluminum oxide, silicon oxide, magnesium oxide, chromium oxide, zirconium oxide, titanium oxide, calcium oxide, fireclay, silicon carbide, tungsten, mullite, dolomite, magnesite, magnesium aluminum oxide, chromite, magnetite, or a combination comprising at least one of the foregoing; and a protective material disposed within the plurality of pores of the refractory material, wherein the protective material is selected from the group consisting of aluminum oxide, chromium oxide, silica, rare earth oxides, rare earth zirconates, titanium oxide, mullite, zirconium oxide, zirconium silicate, yttrium oxide, magnesium oxide, iron oxide, and blends thereof.

Abstract: An article resistant to recession in high temperature environments, and methods for making the article, are presented herein. The article comprises a substrate, an intermediate coating system disposed over the substrate, and a topcoat disposed over the intermediate coating system. The intermediate coating system comprises a separator layer comprising an oxygen getter material, and a barrier layer disposed over the separator layer, the barrier layer comprising a ceramic composition. The topcoat also comprises this ceramic composition. Moreover, at least about 50% by volume of the ceramic composition present in the barrier layer is a metastable precursor material that tends to transform over time into a product material. At least about 75% by volume of the ceramic composition present in the topcoat is the product material, and up to about 25% by volume of the ceramic composition present in the topcoat is the metastable precursor material.

Abstract: An article for use in aggressive environments is presented. In one embodiment, the article comprises a substrate and a self-sealing and substantially hermetic sealing layer disposed over the bondcoat. The substrate may be any high-temperature material, including, for instance, silicon-bearing ceramics and ceramic matrix composites. A method for making such articles is also presented. The method comprises providing a substrate; disposing a self-sealing layer over the substrate; and heating the sealing layer to a sealing temperature at which at least a portion of the sealing layer will flow.

Abstract: A treated refractory material includes a sintered porous refractory material having one or more protective materials disposed within pores of the refractory material, wherein the protective material is selected from the group consisting of aluminum oxide, chromium oxide, silica, rare earth oxides, rare earth zirconates, titanium oxide, mullite, zirconium oxide, zirconium silicate, yttrium oxide, magnesium oxide, iron oxide, and blends thereof. Methods of preparing the treated refractory material are also provided. The treated refractory material provides protection from the penetration of slag and extends the service life of the refractory.

Abstract: A coating for silicon based materials such as those used in high temperature, aqueous environments. An aspect of the invention is directed to an article including a silicon based substrate, a bond coat comprising silicon, and a barrier coat. The barrier coat includes an aluminate such as an alkaline earth metal aluminate or a rare earth aluminate. The barrier coat may be an intermediate coat between the bond coat and a top coat, or it may be the top coat.

Abstract: A coating for a silicon based material such as those used in high temperature environments. An aspect of the invention is directed to an environmental barrier coating including a silicon bond coat, and intermediate coat, and a top coat. The intermediate coat may comprise tantalum aluminate, niobium aluminate, or a mixture of the two. The intermediate coat is resistant to solid-state suburface reactions with the bond coat and the top coat and is substantially inert to reactions with silica at high temperatures.

Abstract: A method and system for cleaning a metal article. The system is used to employ a method that comprises placing the article in a means defining a chamber; subjecting the article to a gaseous atmosphere in the means defining a chamber, where the gaseous atmosphere consisting essentially of carbon, hydrogen, and fluorine; and subjecting the article to the gaseous atmosphere at a temperature in a range from about 815° C. to about 1100° C. to clean the article.

Abstract: A method and system for cleaning a metal article. The system is used to employ a method that comprises placing the article in a means defining a chamber; subjecting the article to a gaseous atmosphere in the means defining a chamber, where the gaseous atmosphere consisting essentially of carbon, hydrogen, and fluorine; and subjecting the article to the gaseous atmosphere at a temperature in a range from about 815° C. to about 1100° C. to clean the article.

Abstract: A method and system for cleaning a metal article. The system is used to employ a method that comprises placing the article in a means defining a chamber; subjecting the article to a gaseous atmosphere in the means defining a chamber, where the gaseous atmosphere consisting essentially of carbon, hydrogen, and fluorine; and subjecting the article to the gaseous atmosphere at a temperature in a range from about 815° C. to about 1100° C. to clean the article.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a barium-strontium alumino silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a barium-strontium alumino silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a yttrium silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a calcium alumino silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a yttrium silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a calcium alumino silicate.