Articles for high temperature service and methods for their manufacture

摘要

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 comprising an alkaline-earth aluminosilicate 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 alkaline-earth aluminosilicate 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.

主权项

1. A method for making an article, comprising:
providing a substrate; disposing a self-sealing layer over the substrate, wherein the self-sealing layer comprises an alkaline-earth aluminosilicate; disposing a bondcoat between the substrate and the self-sealing layer; heating the self-sealing layer to a sealing temperature in a range from about 950 degrees Celsius to about 1350 degrees Celsius at which at least a portion of the self-sealing layer will flow: and flowing a liquid or glassy phase material from the self-sealing layer into cracks and pores within the self-sealing layer; and disposing a topcoat over the self-sealing layer, wherein the topcoat comprises a rare earth monosilicate, a rare earth disilicate, or combinations thereof, wherein the hondcoat comprises at least one material selected from the group consisting of elemental silicon and a silicide.