BAE Systems PLC
SUPERPLASTIC FORMING AND DIFFUSION BONDING PROCESS

Abstract:

A process and apparatus for forming a structure comprising: a) forming a pack from a skin sheet and a core sheet, b) placing the pack in a mould and heating the pack; c) injecting a first gas between the core and skin sheets to urge the skin sheet against the mould; d) injecting a second 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 of the second gas thereby diffusion bonding the sheets; and f) injecting a third gas between the skin sheet and the mould, to force the skin sheet against the core sheet.