| 摘要 |
A method is claimed for the fabrication of a component, incorporating a closed cavity (9a,9b), from two sheets (1,2) in which one at least is suitable for super-plastic forming and in which both are suitable for being welded together by diffusion. The method consists of:- a) welding the two sheets (1,2) by diffusion following at least one outline delimiting the periphery of the cavity (9a,9b), whilst feeding at least one passage (7,8) for the circulation of fluid and whilst avoiding the diffusion welding of the sheets (1,2) in the area thus delimited; and b) the super-plastic forming of the delimited region by the application of a pressure between the sheets, the deformation being limited by a pair of moulds (16,17) of which at least one (17) presents at least one shaping dish, the moulds (17,18) being mounted between the plates of a press for diffusion welding and super-plastic forming. In order to avoid diffusion welding in the delimited zone which forms the closed cavity (9a,9b):- a) a sealed zone is created by welding prior to the introduction of the sheets (1,2) between the plates of the press; b) the air trapped in the sealed pocket is evacuated; c) the sheets are introduced into the moulds and a localised pressure is exerted on the sheets to hermetically seal the delimited zone ; d) a pneumatic pressure is created in the delimited zone to provoke the diffusion welding and the super-plastic forming of the closed cavity (9a,9b). The application of this method to the production of stiffeners in a flat structure as a constituent part of an airship, such as a secondary structure in front of a reactor mast, is also claimed.
|
