Abstract: An injection molding machine or extruder 10 for injecting a foamed thermoplastic material 82 into a mold 12 for forming a shaped article at a relatively low pressure. The injection molding machine comprises a barrel 20 housing a screw 22 disposed in a relatively loose clearance with respect to an inner surface 24 of the barrel. This loose clearance provides for churning a molten thermoplastic material into a foamed condition, which is then introduced into a mold. As the thermoplastic material cools, its foamed characteristic retards shrinkage of the thermoplastic material.

Abstract: A free standing, self-supporting ceramic superplastic forming die assembly having a configuration that provides sufficient strength to resist a compressive load exerted by a press to hold a die lid on a die body against an oppositely directed force generated by gas at superplastic forming pressures within the die, and provides sufficient tensile strength, when under pressure of compressive loads exerted by the press to resist internal bursting force exerted by gas at superplastic forming pressures within the die, thereby making possible the use of a ceramic die for superplastic forming applications without the need of a surrounding containment pressure vessel.

Abstract: A gas management system for delivering forming gas under a controlled pressure through a first portion of a piping network to a region of a forming die between a die lid and a blank to be formed in a superplastic forming machine includes a gas pressure regulator in the piping network and two control loops. The first control loop has a first pressure transducer communicating with the piping network downstream of the gas pressure regulator and operatively with the gas pressure regulator. The second control loop includes a pulse controller downstream of the first pressure transducer and a second pressure transducer communicating with the piping network downstream of the pulse controller and operatively with the pulse controller. The gas pressure regulator receives signals from a controller to adjust the pressure at which the gas pressure regulator opens to release gas through the pressure regulator.

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.