Abstract: A method for applying diffusion aluminide coating on a selective area of a turbine engine component and the coating produced by that method is disclosed. A quartz infrared lamp heats only substantially the localized area of the component to be coated, rather than the complete part. Either halide activated or non-activated tape is applied on the area to be coated and is held in place during coating using a high temperature dimensionally stable tape holder manufactured from graphite or ceramic. The quartz infrared lamp is used to heat only the desired area to a coating temperature of about 1800° F. to about 2000° F. under an inert atmosphere for about 3 to about 8 hours to achieve the desired aluminide coating thickness. No powder masking of the machined surface area is required. Due to the localized heating, aluminum vapor generated from the tape will only deposit aluminide coating on the taped area.

Abstract: A method is provided for refurbishing a service operated metallic coating on a substrate alloy, the coating including at least within a coating outer surface at least one oxide chemically grown from at least one coating element, for example Al, and chemically bonded with the coating outer surface as a result of thermal exposure during service operation. Growth of the oxide has depleted at least a portion of the coating element from the coating. The method comprises removing the oxide from the coating outer surface while substantially retaining the metallic coating, thereby exposing in the coating outer surface at least one surface void that had been occupied by the oxide. The retained metallic coating is mechanically worked, substantially without removal of the retained coating, to close the void, providing a treated metallic coating surface over which a refurbishing coating is applied.

Abstract: A method is provided for refurbishing a service operated metallic coating on a substrate alloy, the coating including at least within a coating outer surface at least one oxide chemically grown from at least one coating element, for example Al, and chemically bonded with the coating outer surface as a result of thermal exposure during service operation. Growth of the oxide has depleted at least a portion of the coating element from the coating. The method comprises removing the oxide from the coating outer surface while substantially retaining the metallic coating, thereby exposing in the coating outer surface at least one surface void that had been occupied by the oxide. The retained metallic coating is mechanically worked, substantially without removal of the retained coating, to close the void, providing a treated metallic coating surface over which a refurbishing coating is applied.

Abstract: A method is provided for repairing an article having a fissure in a metallic overlay environmental resistant coating that includes the element Al, for example an overlay coating of the MCrAlY type. The method depletes more than about 90 wt. % of the Al from an exposed coating surface within the fissure and from a coating outer surface adjacent the fissure, to a depth of at least about 7 mils, without removal of the coating and while substantially maintaining the coating thickness. Thereafter, the fissure is repaired.