Abstract: It is disclosed a bond or overlay MCrAlY-coating for the use within a high temperature environment for the protection of the base alloy of turbine blades and vanes. The MCrAlY-coating having a ? or ?/??-structure comprises a dispersion of ?-NiAl and/or ?/?-MCrAlY particles. This provides a reservoir of aluminum reservoir to coatings wherein the reservoir replenish the aluminum lost due to oxidation and interdiffusion during service. The ?-NiAl and/or ?/?-MCrAlY is the aluminum reservoir and is applied by mixing appropriate powders with ? or ?/?? powders.

Abstract: It is a method of repairing a ceramic coating of an article after use of this article in a high temperature environment disclosed. The ceramic coating is removed locally at spalled areas, at the areas where the ceramic coating is removed locally a mixture including a powder of zirconia stabilized with one or a combination of yttria, calcia, scandia, magnesia, ceria and oxides of the rare earth group, and hydrated metallic halides as a binder is applied and the applied ceramic powder is dried.

Abstract: The present invention relates to a method for forming an article having a protective ceramic coating which reduces radiation heat transport through the ceramic coating. The protective ceramic coating includes one or more embedded reflective metallic layers for reducing the radiation heat transport. The method for forming the protective coating broadly comprises the steps of forming a ceramic coating on a substrate and embedding at least one reflective metallic layer within the ceramic coating.

Abstract: The invention describes a temperature-stable protective coating over a metallic substrate surface (1), which coating includes at least one layer of material (4) consisting of MCrAlY, where M represents at least one of the elements selected from the group of materials consisting of Fe, Co and Ni. The invention also describes a production process for this coating.

Abstract: The invention describes a temperature-stable protective coating over a metallic substrate surface (1), which coating includes at least one layer of material (4) consisting of MCrAlY, where M represents at least one of the elements selected from the group of materials consisting of Fe, Co and Ni. The invention also describes a production process for this coating.

Abstract: The invention relates to a process of repairing a MCrAlY-coating of an article, which has being exposed to the hot gases of, for example, a gas turbine. The MCrAlY-coating is examined and repaired only locally where it is needed and then, subsequently, on top of the MCrAlY-coating the article is aluminized and/or chromized, avoiding the stripping of the whole coating and re-coating over the entire surface of the article. This is for replenishing the coating of Al and/or Cr that become depleted during engine operation, in an easy, cost and time saving manner.

Abstract: The present invention relates to a method for forming an article having a protective ceramic coating which reduces radiation heat transport through the ceramic coating. The protective ceramic coating includes one or more embedded reflective metallic layers for reducing the radiation heat transport. The method for forming the protective coating broadly comprises the steps of forming a ceramic coating on a substrate and embedding at least one reflective metallic layer within the ceramic coating.

Abstract: It is disclosed a bond or overlay MCrAlY-coating for the use within a high temperature environment for the protection of the base alloy of turbine blades and vanes. The MCrAlY-coating having a &ggr; or &ggr;/&ggr;′-structure comprises a dispersion of &bgr;-NiAl and/or y/&bgr;-MCrAlY particles. This provides a reservoir of aluminum reservoir to coatings wherein the reservoir replenish the aluminum lost due to oxidation and interdiffusion during service. The &bgr;-NiAl and/or y/&bgr;-MCrAlY is the aluminum reservoir and is applied by mixing appropriate powders with &ggr; or &ggr;/&ggr;′ powders.

Abstract: It is a method of repairing a ceramic coating of an article after use of this article in a high temperature environment disclosed. The ceramic coating is removed locally at spalled areas, at the areas where the ceramic coating is removed locally a mixture including a powder of zirconia stabilized with one or a combination of yttria, calcia, scandia, magnesia, ceria and oxides of the rare earth group, and hydrated metallic halides as a binder is applied and the applied ceramic powder is dried.

Abstract: The invention relates to a process of repairing a MCrAlY-coating of an article, which has being exposed to the hot gases of, for example, a gas turbine. The MCrAlY-coating is examined and repaired only locally where it is needed and then, subsequently, on top of the MCrAlY-coating the article is aluminized and/or chromized, avoiding the stripping of the whole coating and re-coating over the entire surface of the article. This is for replenishing the coating of Al and/or Cr that become depleted during engine operation, in an easy, cost and time saving manner.

Abstract: A method is taught for protecting copper and copper-based composites from high temperature oxidation, by the application thereto of a cobalt-based alloy diffusion barrier and a copper-aluminum alloy protective outer layer.

Abstract: A thermal barrier coating for high temperature applications has improved resistance to heat flow. The coating comprises a large number of these (nanometer scale) layers separated by interfaces which are effective in retarding heat flow. The coating material will typically be oxide based ceramics and the coating has particular applications in gas turbine engines.

Abstract: A method for determining whether surface connected, through thickness defects exist in a coated carbon-carbon composite article. The method involves the immersion of the coated article in a low viscosity liquid; if a stream of bubbles rises from the surface of the coating, such bubbles indicate the existence of at least one surface connected, through thickness defect in the coating.

Abstract: A method is taught for protecting the surface of a metal subject to hydrogen embrittlement from hydrogen absorption. An adherent coating is formed on the surface of the metal substrate by heating the substrate, applying thereto a colloidal alumina suspension in a vaporizable carrier, and further heating said substrate and applied alumina suspension at an elevated temperature to form a protective alumina coating. Dopants may be employed to increase the inhibition of hydrogen diffusion through the alumina coating.

Abstract: Heat pipe (10) includes an acute angle leading wedge shape form (38) with a radiused leading edge (26). Engine fuel supply (65) cools the trailing wedge shape form (40). The intense heat flux at the leading edge is cleanly dissipated and spread over substantial heat pipe cooling surface (64, 66). A coating (36) on the external surface of the leading edge wedge shape form is formed of a layer of iridium and a layer of oxide.

Abstract: Compositions and articles are described which have particular utility in gas turbine engine parts and which can be used at temperatures up to and in excess of 2,000.degree. F. without the usual protective coatings. Compositions are described which can be formed into single crystal articles which are alumina formers upon exposure to oxidation and in which develop an adherent spall resistant alumina scale during oxidation. The adherence and spall resistance of the alumina surface scale results from the presence of a small but critical quantity of zirconium.

Abstract: A class of protected coatings for superalloys is described in which the coatings compositions are based on the compositions of the underlying substrate. By tailoring the coatings to the substrate composition, diffusional stability results and the other mechanical properties of the coating such as coefficient of thermal expansion and modulus, are similar to that of the substrate. The coating contains 7.5-11% Al, 9-16% Cr, 0.1-0.5% Hf, 2-8% Ta, 0.01-0.8% Y, balance Ni along with other elements all chosen to be similar in type and quantity to the substrate composition.

Abstract: NiCrAl alloys are improved by the addition of zirconium. These alloys are in the .beta. or .gamma./.gamma.'+.beta. region of the ternary system.Zirconium is added in a very low amount between 0.06 and 0.20 weight percent. There is a narrow optimum zirconium level at the low value of 0.13 weight percent.Maximum resistance to cyclic oxidation is achieved when the zirconium addition is at the optimum value.