A porous seal element usable as a blade tip seal in a turbomachine or as an element of a labyrinth seal is made up of a large number of strips disposed edgewise to the sealing face of the element and extending in the direction of relative movement of the seal elements. The strips have grooves extending across the strip for discharge of a cooling fluid such as air. The presence of the grooves provides a low density structure at the seal face of the seal element which may be abraded if there is rubbing contact and provides for metering of coolant at the rear face of the seal element. The seal element is fabricated by etching sheets so each sheet defines a number of parallel strips joined by weak ties and with the grooves extending across the strips; stacking the sheets and bonding them together; and then separating the bonded structure at the weak ties so that each stack of strips defines a seal element.
A stack of metallic sheets is constructed for selective diffusion bonding followed by superplastic forming to yield a metallic sandwich structure. The invention resides in the provision of gas distribution channels in the stack for assuring balanced and complete distribution of gas throughout the unbonded areas of the stack. The gas is used for expansion of the stack into a sandwich structure during the step of superplastic forming. The novel construction of each channel comprises superimposed grooves in opposed face sheets of the stack and slots in the core sheet(s) of the stack.
A single-cast, thin wall structure capable of withstanding impinging gases at temperatures of 4300.degree. F. and higher, and method of making the same.
The present invention relates to a method and apparatus for producing a cast structure. In one embodiment of the present invention an alloy casting mold has molten alloy injected therein to facilitate completely filling a part cavity within the mold. Further, an alloy charge pressure control device is utilized to reduce the charge pressure of the molten alloy during its injection into the mold cavity to minimize distortion and creep of the ceramic shell. In one form of the present invention the charge pressure control device removes excess alloy so as to reduce the head pressure of the molten alloy thereby eliminating the undesirable creep of the ceramic shell.
A gas turbine component that includes a very thin wall. The gas turbine component being of a single-piece, single-cast structure. In one form of the gas turbine component it is formed of a superalloy composition and is capable of withstanding gases impinging upon the walls at temperatures greater than 4000.degree. F.
Disclosed is an integral single-cast multi wall structure including a very thin wall and a second thin wall. There is a passageway interposed between the pair of walls of the structure, and a high thermal conductivity member extends into said passageways and thermally couples the walls. The high thermal conductivity member increases the heat transfer between the walls of the structure. The present invention further includes a method for casting an integral structure having very thin walls that utilizes the high thermally conductive member in the casting process to hold the pattern and cores in alignment.
