SUPERPLASTIC FORGING DESIGN OF A JET ENGINE DISK BY THE FINITE-ELEMENT METHOD

Process design in superplastic bulk forming to produce a nickel-base j et engine disk has been carried out using the rigid-viscoplastic finit e element method. This study aims at deriving systematic procedures in forging of a superalloy engine disk, and develops a scheme to control strain-rate within the range of superplastic deformation during the f orging operation. The new process, using a pancake shaped preform, is designed to have less manufacturing time, and a more even distribution of effective strain in the final product, while the conventional supe rplastic forging of an engine disk has been produced using a cylindric al billet. The process information required for the operation using th e pancake-shaped preform is obtained from numerical analysis on the co nventional forging of superplasticity, and then applied to the new pro cess design.