GEWOELBTE SCHICHTSTRUKTUR UND VERFAHREN ZU IHRER HERSTELLUNG DURCH SUPERPLASTISCHE VERFORMUNG UND DIFFUSIONSSCHWEISSUNG.

摘要

The present invention provides a method of making a domed structure having a peak (20)using superplastic forming and diffusion bonding techniques. The method includes the step of forming a stack (19) of two or more sheets (10,11,12; 14,16,17; 22,23) made of superplastic material and the sheets of the stack being joined together in face to face contact by metallic bonds (13) such that neither of the sheets so joined is bonded to any other sheet in the stack; the metallic bonds (13) preferably lie on lines extending radially from and/or circumferentially around the said peak. The resulting stack (19) is heated to superplastic temperatures and a pressure differential is established across the stack to form it into a domed shape (19a). The resulting dome is placed in a mould (32) and heated; an inert gas is injected between the sheets to inflate the stack superplastically thereby forming a space between the sheets which is divided into cells (45) by webs (39) formed from two of the said sheets that have been superplastically formed by the inflation process.