Abstract: An improved thermal barrier coating is disclosed. The coating is formed on a metal part to be exposed to high temperature gases. The metal part is first coated with an adherent sublayer of MCrAlY alloy. In this case, the M of the MCrAlY is nickel, cobalt, iron, or some combination of these metals. A diffused layer of MCrAlY combined with a low concentration of mullite is formed over the MCrAlY subcoating and the mullite is increased in concentration as the thickness of the layer increases. The outer surface of the layer is all mullite. Improved life expectancy and decreased thermal conductivity is achieved.

Abstract: There is provided by the present invention an alloy which is mechanically and chemically compatible with advanced nickel-base superalloys and nickel-base eutectic superalloys and which possesses excellent resistance to high temperature oxidation. The alloy of the invention is, therefore, particularly useful as a protective environmental coating for the external surfaces of hot-stage aircraft gas turbine engine components, e.g., rotating blades and stationary vanes, made from such advanced superalloys.

Abstract: Dense layers of metals and compounds may be formed on a receiving surface of complex geometry by use of a plasma spray technique in a vacuum chamber in which multiple guns are used simultaneously to deposit material confronting areas.

Abstract: Dense layers of metals and compounds may be formed on a receiving surface of simple geometry by use of a plasma spray technique in a vacuum chamber in which multiple guns are used simultaneously to deposit material in overlapping areas.

Abstract: Gas turbine engine superalloy airfoils and other components having unique microstructures and novel combinations of physical properties are produced rapidly and economically by the method of the invention which uses the low pressure/high velocity plasma spray-casting process and segmented mandrels.

Abstract: Gas turbine engine superalloy airfoils and other components made by low pressure/high velocity plasma spray-casting have unique microstructures and, consequently, novel combinations of physical properties superior to those of components of the same alloy compositions made by conventional methods.

Abstract: In the method for fabrication of water-cooled composite nozzle and bucket hardware for high temperature gas turbines, a high thermal conductivity copper alloy is applied, employing a high velocity/low pressure (HV/LP) plasma arc spraying process, to an assembly comprising a structural framework of copper alloy or a nickel-based super alloy, or combination of the two, and overlying cooling tubes. The copper alloy is plamsa sprayed to a coating thickness sufficient to completely cover the cooling tubes, and to allow for machining back of the copper alloy to create a smooth surface having a thickness of from 0.010 inch (0.254 mm) to 0.150 inch (3.18 mm) or more. The layer of copper applied by the plasma spraying has no continuous porosity, and advantageously may readily be employed to sustain a pressure differential during hot isostatic pressing (HIP) bonding of the overall structure to enhance bonding by solid state diffusion between the component parts of the structure.

Abstract: An article of manufacture having improved high temperature oxidation and corrosion resistance comprising: (a) a superalloy substrate containing a carbide reinforcing phase, and (b) a coating consisting of chromium, aluminum, carbon, at least one element selected from iron, cobalt or nickel, and optionally an element selected from yttrium or the rare earth elements.

Abstract: An article of manufacture having improved high temperature oxidation and corrosion resistance comprising: (a) a superalloy substrate containing a carbide reinforcing phase, and (b) a coating consisting of chromium, aluminum, carbon, at least one element selected from iron, cobalt or nickel, and optionally an element selected from yttrium or the rare earth elements.

Abstract: A flame sprayed high energy milled powder coated article comprising a superalloy substrate and a coating consisting of chromium and at least one element selected from iron, cobalt or nickel. Optionally the coating can contain other elements, e.g., aluminum, carbon, yttrium or the rare earth elements.

Abstract: A high temperature oxidation and corrosion resistant coated nickel-base superalloy article comprising (a) a nickel-base superalloy article, and (b) a first CoCrAl(Y) coating composition consisting essentially of, on a weight basis, approximately 26-32% chromium, 3-9% aluminum, 0-1% yttrium, the rare earth elements, platinum or rhodium, and the balance nickel.

Abstract: A high temperature oxidation resistant dispersion strengthened nickel-chromium alloy body is described. The alloy body comprises a first coating of metallic cobalt and a second coating of aluminum.

Abstract: The invention relates to a method of forming a high temperature oxidation resistant coating on a nickel-chromium alloy body. The method includes incorporating into a nickel-chromium alloy a sufficient amount of cobalt to effect a change in coating morphology when the alloy is aluminized; and thereafter subjecting the body to a coating of aluminum.

Abstract: A protective coating is provided for nickel-base and cobalt-base superalloys which is highly resistant to corrosion and oxidation in a fused Na.sub.2 SO.sub.4 environment at elevated temperatures. The superalloy body is coated by physical vapor deposition with a composition consisting essentially of 50-80% by weight of cobalt and 20-50% by weight of chromium. Optionally, the body may then be coated with an overlayer of aluminum and heat treated to cause interdiffusion of aluminum into the undercoating and thereby enhance the hot corrosion and oxidation resistance of the superalloy body.

Abstract: A protective coating is provided for nickel-base and cobalt-base superalloys which is highly resistant to corrosion in a fused Na.sub.2 SO.sub.4 environment at elevated temperatures. The superalloy body is coated by physical vapor deposition with a thin layer of nickel-chromium alloy and then coated with a still thinner layer of aluminum and thereafter heat treated to strengthen the body and improve its rupture life while bonding the alloy coating to the body and diffusing the aluminum coating into the alloy coating and forming a chromium diffusion barrier in the nickel-chromium layer.

Abstract: A method of forming a high temperature oxidation resistant coating on a thoria dispersion strengthened nickel-chromium alloy body is provided. The method includes applying to the surface of the body a first coating of metallic cobalt, diffusing the cobalt into the body, and thereafter subjecting the body to a second coating of aluminum.

Abstract: A high temperature oxidation and corrosion resistant coated nickel-base superalloy article comprising (a) a nickel-base superalloy article, and .[.(b) a first.]. .Iadd.adjacent thereto (b) a .Iaddend.CoCrAl(Y) coating .Iadd.having a substantially uniform .Iaddend.composition .[.consisting essentially.]. .Iadd.composed .Iaddend.of, on a weight basis, approximately 26-32% chromium, 3-9% aluminum, 0-1% yttrium, the rare earth elements, platinum or rhodium, and the balance .[.nickel.]. .Iadd.cobalt and impurities ordinarily associated with the aforementioned constituents. .Iaddend.