Forming metal parts using superplastic metal alloys and axial compression

Abstract

Abstract A method for forming metal parts from superplastic metal alloys uses axial compression of the blank starting material. A blank of the superplastic metal alloy is enclosed within a die press. The blank is generally tubular, although not necessarily circular, and has an aperture at each end. The ends of the blank are enclosed within correspondingly shaped sections of a cavity within the die press, while the center of the blank is disposed within a central cavity defining a desired shape of the metal part to be formed. Each end of the blank is then sealed with a ram or stop member, and the die press and blank are heated to a forming temperature that is within the superplastic temperature range of the metal alloy. Gas is supplied under pressure to the inside of the blank to produce an outward pressure urging the blank to deform outwardly within the central cavity of the die press. The blank is simultaneously compressed axially with one or both of the rams or stops, to cause additional superplastic metal alloy to be supplied to the central cavity as the blank undergoes superplastic flowing, so that thinning of the blank is limited during the formation of the part. The pressures inducing the superplastic flowing and the rate of axial compression can be varied in different combinations to produce parts with a wide range of shapes and thicknesses. These procedures are preferably performed under preprogrammed direction by a computer to attain precise control and repeatability.

Inventors

• 👤 Daniel G. Sanders
• 👤 Bruce M. Burg

Bibliographic Details