Abstract: A method of removing a core from a CMC component in which the core was used to form an internal cavity. According to one embodiment of the invention, the core is removed from a fully densified CMC component by heating the component and core to a temperature at which the core deteriorates but below a temperature at which the component would melt or otherwise be damaged. According to a second embodiment of this invention, the component is only partially densified, and then impregnated with a coating material that is resistant to a leaching compound capable of removing the core. The core can then be removed using the leaching compound without damage to the internal surfaces of the component defined by the core when the component was fabricated.

Abstract: A method of removing a core from a CMC component in which the core was used to form an internal cavity. According to one embodiment of the invention, the core is removed from a fully densified CMC component by heating the component and core to a temperature at which the core deteriorates but below a temperature at which the component would melt or otherwise be damaged. According to a second embodiment of this invention, the component is only partially densified, and then impregnated with a coating material that is resistant to a leaching compound capable of removing the core. The core can then be removed using the leaching compound without damage to the internal surfaces of the component defined by the core when the component was fabricated.

Abstract: A method of removing a core from a CMC component in which the core was used to form an internal cavity. According to one embodiment of the invention, the core is removed from a fully densified CMC component by heating the component and core to a temperature at which the core deteriorates but below a temperature at which the component would melt or otherwise be damaged. According to a second embodiment of this invention, the component is only partially densified, and then impregnated with a coating material that is resistant to a leaching compound capable of removing the core. The core can then be removed using the leaching compound without damage to the internal surfaces of the component defined by the core when the component was fabricated.

Abstract: A metallic article is provided with improved resistance to high temperature environmental conditions, particularly hot corrosion resistance, through the interdiffusion with the article substrate of a complex graded coating including an inner portion which includes Cr and at least one of the elements Fe, Co and Ni and an outer portion including Al and at least one element selected from Hf, Pt, Rh and Pd.

Abstract: A metallic article is provided with improved resistance to high temperature environmental conditions, particularly hot corrosion resistance, through the interdiffusion with the article substrate of a complex graded coating including an inner portion which includes Al, Cr and at least one of the elements Fe, Co and Ni and an outer portion including at least one element selected from Hf, Pt, Rh and Pd.

Abstract: A metallic article is provided with improved resistance to high temperature environmental conditions through the inclusion of about 0.1 - 10 weight percent Hf in an article surface, such as through coating. A method for providing such a coating includes application of the Hf alone or in combination with other surface protective means. Application of Hf can occur before, during or after use of such protective means.

Abstract: An alloy based on Fe, Co or Ni, and including Al, is provided with improved environmental resistance through the inclusion in the composition of the combination of 0.1-10 weight percent Hf and 0.5-20 wt. % of an element selected from Pt, Rh and Pd. The combination is particularly useful in providing an article coated with such alloy.

Abstract: A metallic article is provided with improved resistance to high temperature environmental conditions through the inclusion of about 0.1-10 weight percent Hf in an article surface, such as through coating. A method for providing such a coating includes application of the Hf alone or in combination with other surface protective means. Application of Hf can occur before, during or after use of such protective means.

Abstract: An alloy based on Fe, Co or Ni, and including Al, is provided with improved environmental resistance through the inclusion in the composition of the combination of 0.1-10 weight percent Hf and 0.5-20 wt. % of an element selected from Pt, Rh and Pd. The combination is particularly useful in providing an article coated with such alloy.

Abstract: A metallic article is provided with improved resistance to high temperature environmental conditions through the inclusion of about 0.1-10 weight percent Hf in an article surface, such as through coating. A method for providing such a coating includes application of the Hf alone or in combination with other surface protective means. Application of Hf can occur before, during or after use of such protective means.