Abstract: An article having a substrate is protected by a thermal barrier coating system. An interfacial layer contacts the upper surface of the substrate. The interfacial layer may comprise a bond coat only, or a bond coat and an overlay coat. The interfacial layer has on its upper surface a preselected, controllable pattern of three-dimensional features, such as grooves in a parallel array or in two angularly offset arrays. The features are formed by an ablation process using an ultraviolet laser such as an excimer laser. A ceramic thermal barrier coating is deposited over the pattern of features on the upper surface of the interfacial layer.

Abstract: A double wall hot gas path part for turbines, such as an airfoil, combustor, duct or shroud, comprises an outer skin and an inner support wall that are metallurgically bonded to one another. The double wall contains integral channels for passage of cooling air adjacent to the skin. The skin may be a metal alloy skin or a microlaminate structure, including microlaminate composite structures. Microlaminate composites typically have a lower density than that of the material used for the support wall, and a simplified internal geometry, which promote weight reductions in the parts and increases in engine operating efficiency.

Abstract: An improved method for depositing zirconium oxide from a zirconium oxide source onto a substrate by means of physical vapor deposition is described. The method includes the step of adding zirconium metal to the zirconium oxide source, which is usually in the form of a cylindrical ingot. The zirconium metal is present in an amount sufficient to chemically bond with a substantial portion of oxygen which would otherwise be freed from the oxide source, as both the zirconium metal and the zirconium oxide source are evaporated during physical vapor deposition. The invention is especially suited for EB-PVD techniques, in which an electron beam is used to evaporate the zirconium metal and the zirconium oxide source during physical vapor deposition. In one embodiment, the zirconium metal comprises a tube which surrounds and contacts at least a portion of the outer surface of the ingot. In another embodiment, the zirconium metal is in the form of a rod inserted in a cavity within the ingot.

Abstract: A method and apparatus are provided for measuring effective focus of an electron beam directed at a target. The electron beam imparts heat flux into the target to effect a target surface temperature profile thereon. A mathematical process model is used to predict an initial iteration of the temperature profile based on operating beam parameters and based on heat transfer behavioral relationships of the target. The temperature profile is optically measured and then compared with the initial iteration to obtain a residual error therebetween. The predicted temperature profile is iterated by varying the beam focus operating parameter until the residual error is less than a predetermined value for determining the effective beam focus.

Abstract: A method is disclosed for operating an electron beam physical vapor deposition apparatus including a vacuum chamber containing an ingot disposed in a crucible, a workpiece disposed above the ingot, and an electron gun for emitting an electron beam to melt and vaporize the ingot to disperse vapors for deposition coating of the workpiece. The method includes directing a primary electron beam with a primary beam focus in a primary scanning pattern across a top surface of the ingot to melt and vaporize the ingot and develop an ingot melt pool floating atop an underlying ingot substrate. A secondary electron beam is superimposed across the ingot top surface in conjunction with the primary electron beam. The secondary electron beam has a secondary beam focus in a secondary scanning pattern to locally and transiently increase vaporization rate of the melt pool.

Abstract: A method for making double-wall airfoil for applications such as the blades and vanes of gas turbine engines by depositing an airfoil skin over an inner support wall which is separately formed and contains channels filled by a channel filling means. The channel filling means is removed thereby forming integral channels within the double-wall for circulating a cooling gas adjacent to the airfoil skin. The airfoil skin deposited may be a metal alloy skin or a microlaminate structure, including microlaminate composite structures.