United Technologies Corporation

James R Dillner

Peter E Leibfried

David Porter

William R Reimels

Hilton F Stone, Jr

J George Asfalg

A titanium gas injection tube 18 is located within a counterbore (16) in the blade (10) halves which are to be bonded and formed. An internal stainless steel sleeve (24) is placed in the counterbore inside the titanium tube to resist bonding forces. An external stainless steel sleeve (28) is placed around the tube to resist gas pressure forces.

Hollow titanium blade manufacturing

An untwisted hollow blade with internal reinforcing ribs is formed by diffusion bonding two halves. A predominate portion of the blade twist is accomplished by gravity creep deforming against a supporting die, aided by applying twisting moments at the ends. The blade is free to move axially at one end. Simultaneous heat soak for solution heat treatment minimizes overall grain growth. Later, hot forming between heated dies is supplemented with internal blade pressure after die closing. Metal flow is more easily predictable whereby finite element analysis may establish the proper starting form.

Method of forming a hollow blade

A workholder (6) has a contoured bonding surface (7), which essentially matches a contoured surface (4) of an airfoil (1). A plurality of studs (8) are disposed within a plurality of tapped holes (9) located about the workholder bonding surface. In operation, the studs are extended outwardly from the surface, and both the studs and bonding surface are contacted with a release agent (10). A curable resinous material (11) is applied to the bonding surface and studs, and an airfoil positioned next to the bonding surface, sandwiching the resinous material therebetween. After curing, a plurality of tapped holes (13) are formed in resin layer (11), with the extended studs fixably positioning the airfoil relative to the workholder. Removing the studs provides heatless release of the airfoil from the workholder.

Method for securing a workpiece to a workholder

A workholder (6) has a contoured bonding surface (7), which essentially matches a contoured surface (4) of an airfoil (1). A plurality of studs (8) are disposed within a plurality of tapped holes (9) located about the workholder bonding surface. In operation, the studs are extended outwardly from the surface, and both the studs and bonding surface are contacted with a release agent (10). A curable resinous material (11) is applied to the bonding surface and studs, and an airfoil positioned next to the bonding surface, sandwiching the resinous material therebetween. After curing, a plurality of tapped holes (13) are formed in resin layer (11), with the extended studs fixedly positioning the airfoil relative to the workholder. Removing the studs provides heatless release of the airfoil from the workholder.

Workholder for securing a workpiece thereto

Disclosed is an improved method of fabricating boron fiber and aluminum matrix composite structures, especially gas turbine compressor blades having titanium metal skins. Titanium skins and boron aluminum composite cores are preformed by gas pressure and hard dies prior to hot pressing. The composite sheets of the core are preformed with the use of expendable carrier sheets, which hold the stacked sheets firmly as both the carrier sheets and composites are shaped through moderate temperature and gas pressure against a hard die. The preforming permanently shapes and lightly bonds the composite sheets. The skins are preformed in an analogous process using gas pressurization of a metal envelope into die cavities. The skins and composite core are then hot pressed in hard dies to form the finished part.

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Amston, CT, United States of America

James R Dillner