Patent ID: 7134176
Filing Date: 2006-11-14
Classification: B21D,Y10T

Abstract:
1. A process of forming a structure by diffusion bonding and superplastic forming at least one skin sheet and at least one core sheet, the process comprising: a) forming a pack from the at least one skin sheet and the at least one core sheet; b) placing the pack in a mould and heating the pack to a temperature at which the sheets are capable of superplastic deformation; c) injecting a gas between the skin sheet and the core sheet to urge the skin sheet against an internal face of the mould thereby forming a cavity between the skin sheet and the core sheet; d) injecting gas on the side of the core sheet remote from the skin sheet to urge the core sheet against the skin sheet, e) maintaining gas pressure on the said side of the core sheet remote from the skin sheet, thereby forming a diffusion bond between the skin sheet and the core sheet; and f) maintaining a regulated pressure of a gas in the cavity between the skin sheet and the core sheet during at least part of step d); wherein the gas used in step f) to maintain the pressure of gas in the cavity between the skin sheet and the core sheet is a different gas than the gas used in steps d) and e).