Abstract: A turbine blade tip and shroud clearance control coating system comprising an abrasive blade tip coating and an abradable shroud coating are provided. The abrasive layer may comprise abrasive particles of cubic zirconia, cubic hafnia or mixtures thereof, and the abradable layer may be a nanolaminate thermal barrier coating that is softer than the abrasive layer. The invention further provides an alternate coating system comprising an abradable blade tip coating and an abrasive shroud coating.

Abstract: A protective barrier coating system including a diffusion barrier coating and an oxidation barrier coating and method for use in protecting silicon-based ceramic turbine engine components. A complete barrier coating system includes a thermal barrier coating of stabilized zirconia and an environmental barrier coating of an alloyed tantalum oxide. The oxidation barrier coating includes a layer of metallic silicates formed on a substrate of silicon nitride or silicon carbide to be protected. The oxidation barrier coating can include silicates of scandium, ytterbia or yttrium. The oxidation barrier coating may also include an inner layer of Si2ON2 between the diffusion barrier and the metallic silicate layer. The oxidation barrier coating can be applied to the substrate by spraying, slurry dipping and sintering, by a sol-gel process followed by sintering, by plasma spray, or by electron beam-physical vapor deposition.

Abstract: A plurality of powders is admixed to form a substantially homogenous powder mixture comprising each of the alloy elements. At least one of the powders consists essentially of a substantially pure elemental metal. The substantially homogenous powder mixture is cold gas-dynamic sprayed on the substrate to form a coating of the alloy elements. The coating is then heated until the alloy elements inter-diffuse and form the alloy. In an exemplary embodiment, the substantially homogenous powder mixture includes stoichiometric amounts of each of the alloy elements, and each of the powders consists essentially of a substantially pure form of one of the alloy elements.

Abstract: Oxidation protection of a titanium-based alloy is provided with improved fatigue properties by a titanium aluminide coating of between 2 to 12 microns by diffusing the Al into the Ti at a temperature below the melting point of the Al. The coating is gas deposited and protects the titanium-based alloys from oxidation at high temperature utilization.

Abstract: A braze material and method of brazing titanium metals. The material may consist of Ti, Ni, Cu Zr, PM and M where PM is a precious metal and M may be Fe, V, Cr, Co, Mo, Nb, Mn, Si, Sn, Al, B, Gd, Ge or combinations thereof, with the (Cu+PM)/Ni ratio around 0.9. Optionally, a second brazing may be performed to rebraze any braze joint that did not braze successfully. The second brazing material has a lower braze temperature than the first and may consist of a mixture of Ti, Ni, Cu, Zr PM and M with from 1-20 wt % more Zr, PM, M or combinations thereof than the first braze. The braze material may be placed on a base material, in a vacuum furnace, and heated to form a braze joint between the braze and base material. The heating step may occur from about 800-975° C. and over 3 to 15 minutes.

Abstract: A braze material and method of brazing titanium metals. The material may consist of Ti, Ni, Cu Zr, PM and M where PM is a precious metal and M may be Fe, V, Cr, Co, Mo, Nb, Mn, Si, Sn, Al, B, Gd, Ge or combinations thereof, with the (Cu+PM)/Ni ratio around 0.9. Optionally, a second brazing may be performed to rebraze any braze joint that did not braze successfully. The second brazing material has a lower braze temperature than the first and may consist of a mixture of Ti, Ni, Cu, Zr PM and M with from 1-20 wt % more Zr, PM, M or combinations thereof than the first braze. The braze material may be placed on a base material, in a vacuum furnace, and heated to form a braze joint between the braze and base material. The heating step may occur from about 800-975° C. and over 3 to 15 minutes.

Abstract: A method for stabilizing a porous thermal barrier coating plasma sprayed on a substrate comprises the steps of immersing the porous thermal barrier coating in a sol gel comprising a metal oxide or precursor thereof, a solvent, and a surfactant, applying vacuum pressure to the sol gel to infiltrate the porous thermal barrier coating with the sol gel, and drying the sol gel to produce residual metal oxide particles in the porous thermal barrier coating.

Abstract: A protective barrier coating system including a diffusion barrier coating and an oxidation barrier coating and method for use in protecting silicon-based ceramic turbine engine components. A complete barrier coating system includes a thermal barrier coating of stabilized zirconia and an environmental barrier coating of an alloyed tantalum oxide. The oxidation barrier coating includes a layer of metallic silicates formed on a substrate of silicon nitride or silicon carbide to be protected. The oxidation barrier coating can include silicates of scandium, ytterbia or yttrium. The oxidation barrier coating may also include an inner layer of Si2ON2 between the diffusion barrier and the metallic silicate layer. The oxidation barrier coating can be applied to the substrate by spraying, slurry dipping and sintering, by a sol-gel process followed by sintering, by plasma spray, or by electron beam-physical vapor deposition.

Abstract: Oxidation protection of a titanium-based alloy is provided with improved fatigue properties by a titanium aluminide coating of between 2 to 12 microns by diffusing the Al into the Ti at a temperature below the melting point of the Al. The coating is gas deposited and protects the titanium-based alloys from oxidation at high temperature utilization.

Abstract: Oxidation protection of a titanium-based alloy is provided with improved fatigue properties by a titanium aluminide coating of between 2 to 12 microns by diffusing the Al into the Ti at a temperature below the melting point of the Al. The coating is gas deposited and protects the titanium-based alloys from oxidation at high temperature utilization.

Abstract: A braze material and method of brazing titanium metals. The material may consist of Ti, Ni, Cu Zr, PM and M where PM is a precious metal and M may be Fe, V, Cr, Co, Mo, Nb, Mn, Si, Sn, Al, B, Gd, Ge or combinations thereof, with the (Cu+PM)/Ni ratio around 0.9. Optionally, a second brazing may be performed to rebraze any braze joint that did not braze successfully. The second brazing material has a lower braze temperature than the first and may consist of a mixture of Ti, Ni, Cu, Zr PM and M with from 1-20 wt% more Zr, PM, M or combinations thereof than the first braze. The braze material may be placed on a base material, in a vacuum furnace, and heated to form a braze joint between the braze and base material. The heating step may occur from about 800-975° C. and over 3 to 15 minutes.

Abstract: Oxidation protection of a titanium heat exchanger is provided by a titanium aluminide or solgel coating. The coating protects bare titanium and brazed surfaces of the heat exchanger.

Abstract: Oxidation protection of a titanium-based alloy is provided with improved fatigue properties by a titanium aluminide coating of between 2 to 12 microns by diffusing the Al into the Ti at a temperature below the melting point of the Al. The coating is gas deposited and protects the titanium-based alloys from oxidation at high temperature utilization.

Abstract: Oxidation protection of a titanium heat exchanger is provided by a titanium aluminide or solgel coating. The coating protects bare titanium and brazed surfaces of the heat exchanger.

Abstract: A thermal barrier coating for superalloy turbine engine vanes and blades that are exposed to high temperature gas is disclosed. The coating includes an aluminide or MCrAlY layer, an alumina layer, and a ceramic top layer. The ceramic layer has a columnar grain microstructure. A bond inhibitor is disposed in the gaps between the columnar grains. This inhibitor is preferably alumina.

Abstract: The invention provides an aluminum based alloy consisting essentially of the formula Al.sub.bal Fe.sub.a X.sub.b, wherein X is at least one element selected from the group consisting of Zn, Co, Ni, Cr, Mo, V, Zr, Ti, Y and Ce, "a" ranges from about 7-15 wt %, "b" ranges from about 2-10 wt % and the balance is aluminum. The alloy has a predominately microeutectic microstructure. The invention also provides a method and apparatus for forming rapidly solidifed metal, such as the metal alloys of the invention, within an ambient atmosphere. Generally stated, the apparatus includes a moving casting surface which has a quenching region for solidifying molten metal thereon. A reservoir holds molten metal and has orifice means for depositing a stream of molten metal onto the casting surface quenching region. A heating mechanism heats the molten metal contained within the reservoir, and a gas source provides a non-reactive gas atmosphere at the quenching region to minimize oxidation of the deposited metal.

Abstract: The invention provides an aluminum based alloy consisting essentially of the formula Al.sub.bal Fe.sub.a X.sub.b, wherein X is at least one element selected from the group consisting of Zn, Co, Ni, Cr, M, V, Zr, Ti, Y, Si and Ce, "a" ranges from about 7-15 wt %, "b" ranges from about 1.5-10 wt % and the balance is aluminium. The alloy has a predominately microeutectic microstructure.The invention provides a method and apparatus for forming rapidly solidified metal within an ambient atmosphere, the rapidly solidified metal being an aluminum based alloy. Generally stated, the apparatus includes a moving casting surface which has a quenching region for solidifying molten metal thereon. A reservoir holds the molten metal and has orifice means for depositing a stream of the molten metal onto the casting surface quenching region.

Abstract: The invention provides an aluminum based alloy consisting essentially of the formula Al.sub.bal Fe.sub.a X.sub.b, wherein X is at least one element selected from the group consisting of Zn, Co, Ni, Cr, Mo, V, Zr, Ti, Y and Ce, "a" ranges from about 7-15 wt. %, "b" ranges from about 2-10 wt. % and the balance is aluminum. The alloy has a predominately microeutectic microstructure, and is produced by a method and apparatus for forming rapidly solidified metal within an ambient atmosphere. Generally stated, the apparatus includes a moving casting surface which has a quenching region for solidifying molten metal thereon. A reservoir holds molten metal and has orifice means for depositing a stream of molten metal onto the casting surface quenching region. A heating mechanism heats the molten metal contained within the reservoir, and a gas source provides a non-reactive gas atmosphere at the quenching region to minimize oxidation of the deposited metal.

Abstract: The invention provides an aluminum based alloy consisting essentially of the formula Al.sub.bal Fe.sub.a X.sub.b, wherein X is at least one element selected from the group consisting of Zn, Co, Ni, Cr, Mo, V, Zr, Ti, Y, Si and Ce, "a" ranges from about 7-15 wt %, "b" ranges from about 1.5-10 wt % and the balance is aluminum. The alloy has a predominately microeutectic microstructure.The invention also provides a method and apparatus for forming rapidly solidified metal, such as the metal alloys of the invention, within an ambient atmosphere. Generally stated, the apparatus includes a moving casting surface which has a quenching region for solidifying molten metal thereon. A reservoir holds molten metal and has orifice means for depositing a stream of molten metal onto the casting surface quenching region. A heating mechanism heats the molten metal contained within the reservoir, and a gas source provides a non-reactive gas atmosphere at the quenching region to minimize oxidation of the deposited metal.