Patent ID: 7875135

Claim:
A method for using a fixture to differentially heat treat a superalloy turbine blade, comprising the steps of: providing a turbine blade having an airfoil portion, a platform portion, a shank portion below the platform portion and a dovetail portion below the shank portion; providing a source of cooling fluid; providing a fixture for supporting the turbine blade, the fixture further comprising a material of high conductivity, a receptacle corresponding to at least a part of a blade surface below the platform portion of the turbine blade, the receptacle providing surface contact with at least the part of the blade surface below the platform surface when inserted therein so that at least the airfoil portion of the blade projects away from the fixture, an orifice having an inlet and an outlet, the inlet connected to the source of the cooling fluid; inserting at least a part of the blade surface below the platform portion into the receptacle of the fixture; establishing a flow of cooling fluid from the source of cooling fluid through the orifice; providing a heating source; utilizing the heating source to heat the airfoil portion of the blade projecting away from the fixture; and heating the airfoil portion of the blade to a solutioning temperature of the superalloy for a time sufficient to solution gamma prime precipitates, while maintaining at least the part of the blade below the platform in the receptacle of the fixture below the solutioning temperature, the fixture conducting heat away from the blade, and the cooling fluid conducting heat away from the fixture; wherein the step of providing a turbine blade further includes providing a turbine blade having internal cooling passageways, the step of providing a fixture further includes providing a fixture having a means for providing cooling fluid to the internal cooling passageways of the turbine blade, and the step of establishing a flow of cooling fluid further includes establishing a sufficient flow of cooling fluid through the means for providing cooling fluid to the internal cooling passageways so that the temperature of the internal passageways is maintained below an incipient melting temperature of an aluminide coating applied to the internal passageways of the superalloy turbine blade substrate.