Abstract: A metal substrate is anodized in a phosphoric acid anodizing solution. The anodized metal substrate is thereafter contacted with a hexavalent chromium free, trivalent chromium containing acid solution to coat the anodized metal substrate. The coated anodized metal substrate can be adhesively bonded to another such treated metal substrate to form a composite article. The resulting article exhibits excellent bonding and corrosion properties.

Abstract: A composite article comprising of a non-metallic composite core, a fluoroelastomer adhesive layer which has a curing temperature substantially similar to the composite core, and a metallic structure which overlays the fluoroelastomer adhesive layer, wherein the composite article can be formed by co-curing the core and the fluoroelastomer adhesive layer.

Abstract: The present invention related to a method for providing a composite structure and the composite structure formed thereby. The method broadly comprises the steps of: providing a core structure formed from a non-metallic composite material in a substantially uncured state; applying a fluoroelastomer film in a substantially uncured state over surface portions of said core structure; placing a metallic structure over a portion of said core structure, said metallic structure having inner surfaces which contacts said fluoroelastomer film; and molding said composite structure under conditions of heat and pressure for a time sufficient to co-cure said fluoroelastomer film and said non-metallic core structure material and to form a bond between said fluoroelastomer film and said inner surfaces of said metallic structure. The method of the present invention may be used to manufacture original metal/composite structures as well as to refurbish metal/composite structures such as fan exit guide vanes for jet engines.

Abstract: The present invention relates to a method and apparatus for forming abrasive surfaces on the tips of a plurality of workpieces such as the tips of gas turbine airfoil blades. The method broadly comprises the steps of providing a mechanical masking device having a plurality of openings arranged around the circumference of the device, installing an array containing a plurality of workpieces to be coated within the mechanical masking device so that portions of the workpieces including the tips thereof extend through the openings, immersing the mechanical masking device with the installed array of workpieces in a tank containing a plating bath with a matrix material and an abrasive grit material in slurry form so that the workpieces lie in a substantially horizontal plane, and applying a current through the plating bath to form the abrasive surfaces on the tips of the workpieces. The mechanical masking device protects portions of the array from the coating operation.

Abstract: The present invention relates to a method and apparatus for forming abrasive surfaces on the tips of a plurality of workpieces such as the tips of gas turbine airfoil blades. The method broadly comprises the steps of providing a mechanical masking device having a plurality of openings arranged around the circumference of the device, installing an array containing a plurality of workpieces to be coated within the mechanical masking device so that portions of the workpieces including the tips thereof extend through the openings, immersing the mechanical masking device with the installed array of workpieces in a tank containing a plating bath with a matrix material and an abrasive grit material in slurry form so that the workpieces lie in a substantially horizontal plane, and applying a current through the plating bath to form the abrasive surfaces of the tips of the workpieces. The mechanical masking device protects portions of the array form the coating operation.

Abstract: The present invention relates to a method and apparatus for forming abrasive surfaces on the tips of a plurality of workpieces such as the tips of gas turbine airfoil blades. The method broadly comprises the steps of providing a mechanical masking device having a plurality of openings arranged around the circumference of the device, installing an array containing a plurality of workpieces to be coated within the mechanical masking device so that portions of the workpieces including the tips thereof extend through the openings, immersing the mechanical masking device with the installed array of workpieces in a tank containing a plating bath with a matrix material and an abrasive grit material in slurry form so that the workpieces lie in a substantially horizontal plane, and applying a current through the plating bath to form the abrasive surfaces on the tips of the workpieces. The mechanical masking device protects portions of the array from the coating operation.

Abstract: A method and apparatus for increasing blade fatigue strength in a turbine engine. The blades in the turbine engine are configured so as to reduce stress at the tip of the blades during operation of the turbine engine, thus increasing blade fatigue strength. This stress reduction helps to counteract the detrimental effect of abrasive tip coatings on blade fatigue strength. In one embodiment, the tip of the blade is chamfered in order to reduce the stress on the tip of the blade. An abrasive coating is then applied to the tip of the blade to assist the blade in seating into an abradable outer air seal. In another embodiment, an abrasive coating is applied to a center portion of the tip of the blade, with the periphery of the abrasive coating being set back from the opposing surfaces of the blade.

Abstract: The present invention relates to a tool for accurately controlling the location, volume and containment of an abrasive grit material during a plating operation wherein the grit material and a matrix metal are deposited onto a tip portion of at least one workpiece. The tool of the present invention has an inner component with slots for receiving the workpieces to be coated. The tool also has an outer components having a plurality of through slots for permitting a plating solution to flow therethrough and into a space defined by the inner and outer components. The tool further has a slot defined by portions of the inner and outer component for introducing the abrasive grit material into the space. A screen is provided over the slots in the outer component. The screen helps maintain the abrasive grit material within the space while permitting plating solution to flow into the space. The tool of the present invention further has a trough for collecting unused grit material.

Abstract: Processes for making metal prototype parts are described. The key steps of the invention include: making a computer aided design (CAD) file of the prototype part; modifying such file a first time to produce a file of a first mandrel upon which the part will be formed; modifying such file a second time to produce a second mandrel upon which a metal anode will be formed, the anode and first mandrel then being used in an electroplating process to form the prototype. Stereolithographic techniques are preferred for making the mandrels out of polymeric materials.

Abstract: A method for providing an abrasive layer on the surface of a turbine engine component is described. The method includes application of several layers of nickel; one layer includes abrasive particulates. The layer has good bond strength and has a thin cross section, thereby minimizing any effect on the fatigue strength of the component.