Abstract: The turbine blade tip clearance control system presently used with existing turbine blade uses an abradable seal material with a conventional squealer tip. Others use a thin, coating added to the tip of the blade. The present turbine blade tip control system minimizes the problem of controlling the clearance between the blade and the shroud and overcomes the problem of wearing away of the thin coating added to the tip by using a rub tolerant, high-temperature seal material coating on a turbine shroud and a turbine blade made of at least two materials. The combination of the coating and an outer tip being of a different material than the metallic body also minimizes the problems associated with the burning of dirty fuels. The blade has a metallic body of high strength and the outer tip has a strength less than the strength of the body and made of a material resistant to oxidation, sulfidation and thermal fatigue at operating temperatures. The outer tip has a radial length "L" at least 1 mm in length.

Abstract: A metallic gasket for sealing a joint between first and second surfaces subjected to high pressure and high temperature. Other gaskets used to seal such joints are of a fibrous composition held together by a suitable bonding agent and a deformable elastomer coat or bead. Many of these gaskets used for high pressure and high temperature use an asbestos sheet which is regarded as toxic and unsafe to handle. The present gasket is comprised of a substantially non-compressible sheet and pair of seals made from a ductile material connected to opposite sides of the sheet. The sheet and seals are positioned between the surfaces to be sealed and the seals conform to the surface finish topography of the surfaces when a predetermined compressive load is applied between the surfaces resulting in a positive sealed joint suitable for high pressure and high temperature.

Abstract: The turbine blade tip clearance control system presently used with existing turbine blade uses an abradable seal material with a conventional squealer tip. Others use a thin, coating added to the tip of the blade. The present turbine blade tip control system minimizes the problem of controlling the clearance between the blade and the shroud and ovecomes the problem of wearing away of the thin coating added to the tip by using a rub tolerant, high-temperature seal material coating on a turbine shroud and a turbine blade made of at least two materials. The combination of the coating and an outer tip being of a different material than the metallic body also minimizes the problems associated with the burning of dirty fuels. The blade has a metallic body of high strength and the outer tip has a strength less than the strength of the body and made of a material resistant to oxidation, sulfidation and thermal fatigue at operating temperatures. The outer tip has a radial length "L" at least 1 mm in length.