General Electric Company

Gary T Martini

Gene E Wiggs

Jeffrey LeMonds

Jung-Ho Cheng

Raymond Grant Rowe

John Robert Kelley

Richard M Cogan

Ralph E Patsfall

Lawrence J Galaske, Jr

Douglas J White

James E McConnelee

Mark A Robinson

A method is provided for making a two-piece hollow airfoil having a complex geometry. Two metal sheets are formed into initial shapes so as to have a mean camber and twist. A series of raised ribs is machined onto the external side of each of the two sheets. The two sheets are joined together and sealed to form an in-process assembly. The assembly is subjected to high temperature and pressure to diffusion bond the sheets together at selected points. The assembly then subjected to internal pressure at high temperature in order to inflate and superplastically deform the assembly to the desired shape. Excess material is machined off after the inflation step.

Method for manufacturing hollow airfoils (two-piece concept)

An improved method for superplastic forming diffusion bonding includes application of a protective encapsulating coating over the stop-off coating to prevent migration of yttria into regions to be diffusion bond.

Encapsulated stop-off coating for diffusion bonding

A method is provided for making a four-piece hollow airfoil. Four metal sheets are preformed into initial shapes. The sheets are sealed together into two pairs or sub-assemblies. Internal cavities are formed in one sheet from each pair prior to sealing. Each sub-assembly is subjected to high temperature and pressure in order to diffusion bond the sheets together at selected points. The cavities of each sub-assembly are then subjected to internal pressure in order to inflate and superplastically deform the sub-assemblies. The inflated sub-assemblies are combined to form a single assembly and the cavities are again subjected to internal pressure in order to bond the sub-assemblies together. The assembly is then exposed to hot isostatic pressing, after which, excess material is machined off.

Method for manufacturing hollow airfoils (four-piece concept)

A method for making a three-piece hollow airfoil includes preforming three metal sheets into initial shapes and sealing them together to form an in-process assembly. Internal cavities are formed in the assembly prior to sealing. The assembly is subjected to high temperature and pressure to diffusion bond the sheets together at selected points. The cavities are then subjected to internal pressure at high temperature in order to inflate and superplastically deform the assembly to the desired shape. Excess material may be machined off after inflation.

Design and processing method for manufacturing hollow airfoils

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Loveland, OH, United States of America

Gary T Martini