Abstract: A corrosion resistant coating for gas turbine engine includes a glassy ceramic matrix wherein the glassy matrix is silica-based, and includes corrosion resistant particles selected from refractory particles and non-refractory MCrAlX particles, and combinations thereof. The corrosion resistant particles are substantially uniformly distributed within the matrix, and provide the coating with corrosion resistance. Importantly the coating of the present invention has a coefficient of thermal expansion (CTE) greater than that of alumina at engine operating temperatures. The CTE of the coating is sufficiently close to the substrate material such that the coating does not spall after frequent engine cycling at temperatures above 1200° F.

Abstract: A corrosion resistant coating for gas turbine engine includes a glassy ceramic matrix wherein the glassy matrix is silica-based, and includes corrosion resistant particles selected from refractory particles and non-refractory MCrAlX particles, and combinations thereof. The corrosion resistant particles are substantially uniformly distributed within the matrix, and provide the coating with corrosion resistance. Importantly the coating of the present invention has a coefficient of thermal expansion (CTE) greater than that of alumina at engine operating temperatures. The CTE of the coating is sufficiently close to the substrate material such that the coating does not spall after frequent engine cycling at temperatures above 1200° F.

Abstract: Non-spherical particles including a major dimension, for example flakes of material, are positioned with the major dimension oriented generally along an article surface in respect to which the particle is disposed. The particles, disposed in a fluid medium, the viscosity of which can be increased to secure the particles in position, are positioned using a force on the particles. The force includes torque force from a magnetic field, force from flow of the fluid medium, the force of gravity, and the force of surface tension alone or in combination with the force of gravity.

Abstract: Apparatus and method for producing metallic flake having an environmental coating for use in oxidative and corrosive atmospheres. Fluidized bed techniques are utilized to perform a controlled oxidation of metallic particles that include aluminum. The fluidized techniques permit the formation of a thin, outer shell of alumina over the outer surface of the flake. Because the oxidation is controlled so that the selective oxidation produces a thin outer shell, the particle has good reflectance and the metallic core of the particle is unaffected by the oxidizing treatment. Although the techniques of the present invention are effective for producing a reflective surface on aluminum-containing iron alloys while the core particles can be either magnetically soft or hard, the techniques can be used to produce a reflective surface that is corrosion and oxidation resistant on any aluminum containing alloy. Apparatus that facilitates the controlled oxidation is also set forth.

Abstract: A method of forming a multilayer ceramic coating system on a substrate that requires thermal protection from a hostile thermal environment. The method generally entails forming at least one tape that contains ceramic particles dispersed in an organic constituent, such as a binder and/or plasticizer. If a single tape is used, the tape is formed of multiple layers of different compositions and applied as a unit to the substrate, thereby forming at least an innermost layer and an outermost layer on the substrate. If multiple tapes are used, a first tape is applied to the substrate to form the innermost layer, and a second tape is applied to form the outermost layer. The tape/tapes are then sintered to form innermost and outermost ceramic layers, respectively, on the substrate.

Abstract: A coating is prepared by providing a plurality of metallic flake particles, depositing a surface-protective applied layer on the particle surfaces to form protected particles, and mixing the protected particles with a binder precursor to form a coating mixture. The coating mixture is applied to a substrate. The surface-protective applied layer is preferably silica, which is deposited by a sol-gel process from a tetraethyl orthosilicate solution.

Abstract: A coated article suitable for use at elevated temperature is formed of a substrate made from metal or a ceramic, a diffuse reflective barrier coating overlying the substrate, and a low-emissivity top coat covering the diffuse reflective barrier coating. The diffuse reflective barrier coating includes a transmissive medium having a transmissive-medium index of refraction, and a plurality of radiation-scattering centers distributed in the transmissive medium, the radiation-scattering centers having a scattering-center index of refraction different from the transmissive-medium index of refraction. The radiation scattering centers may be voids or second ceramic particles. The diffuse reflective barrier coating has a surface roughness of less than about 150 microinches RMS.

Abstract: An air sprayable, fluid, non-metallic coating mixture to provide an article coating having the ability to reflect at least 75% of heat energy in the frequency range of up to 2.6 microns comprises the combination of two different alpha alumina powders. A first powder predominantly is in a particle size range of less than about 1 micron; a second powder is of a particle size greater than 7 times the particle size of the first powder. The mixture includes a glass powder having a melting point of at least about 1400° F. and of a particle size less than about 45 microns. The mixture includes a binder that will form up to about 80% of its weight in silica when heated to a temperature of at least the melting point of the glass powder. In the article coating, provided by air spraying the mixture onto an article and heating to a temperature sufficient to melt the glass powder and to form the silica from the binder, the glass and silica form a matrix about and binding together the alumina powder.

Abstract: A method of forming a multilayer ceramic coating system on a substrate that requires thermal protection from a hostile thermal environment. The method generally entails forming at least one tape that contains ceramic particles dispersed in an organic constituent, such as a binder and/or plasticizer. If a single tape is used, the tape is formed of multiple layers of different compositions and applied as a unit to the substrate, thereby forming at least an innermost layer and an outermost layer on the substrate. If multiple tapes are used, a first tape is applied to the substrate to form the innermost layer, and a second tape is applied to form the outermost layer. The tape/tapes are then sintered to form innermost and outermost ceramic layers, respectively, on the substrate.

Abstract: A sprayable, non-metallic heat reflecting coating mixture for reflecting heat energy in the frequency range of up to about 5 microns comprises a high temperature zinc compound and a binder substantially transparent to heat energy in the frequency range of up to about 5 microns, in the substantial absence of silica and silica compounds. The mixture and a resulting coating on an article has the capability to reflect an average of at least about 65-85% of heat energy in that frequency range, and stability at temperatures up to about 2000.degree. F. A coating resulting from application of the coating mixture to an article surface has a thickness of greater than about 1 mil up to less than about 10 mils.