Mark-off suppression in superplastic forming and diffusion bonding

摘要

A method of forming a pack in a die by superplastic formation and diffusion bonding comprises applying a forming pressure within the pack to expand the pack within the die; and supplying gas between the die and the pack to apply a back pressure around an outside of the pack while the pack is being expanded to counteract the forming pressure to reduce surface mark off.

主权项

1. A method of forming a pack in a die by superplastic formation and diffusion bonding, the method comprising:
applying a forming pressure within the pack to expand the pack within the die; and supplying positive gas pressure between a first portion of the die and an exterior of the pack while the pack is being expanded to force a sheet of the pack into contact against a surface of a second portion of the die as the pack is being expanded,
wherein the die includes a receiving cavity comprising a funnel shape having a funnel mouth inboard and a cylindrical trough extending from an apex of the funnel shape to an outer edge of the die, and wherein applying the forming pressure within the pack to expand the pack within the die includes supplying a gas to an interior of the pack via a gas inlet tube disposed in the receiving cavity of the die, wherein the receiving cavity creates a gas tight seal between the die and the inlet tube when the die is closed and the gas is supplied.