Patent ID: 7516529

Claim:
A method for making a composite structure, the method consisting of: providing a forming tool defining a curved cavity; providing a flat first sheet metal layer comprising a superplastically formable material; adhering a metal foam precursor layer to said flat first sheet metal layer to form a precursor structure, said precursor layer comprising a mixture of metal powder and a blowing agent; disposing said precursor structure within said forming tool curved cavity; heating said precursor structure to a temperature sufficient for superplastic forming within said forming tool curved cavity; applying hydrostatic pressure to one side of said superplastically deformable material within said forming tool cavity; superplastically forming said precursor structure after adhering said metal foam precursor layer within said forming tool curved cavity; and heating said formed precursor structure to a foaming temperature sufficient to foam said metal foam precursor portion and to fuse the resultant metallic foam to said first sheet metal layer within said forming tool curved cavity; wherein the resultant metallic foam is fused to said first sheet metal layer after said superplastic forming of said first sheet metal layer into a curvilinear shape which mates with a curved shape defined by the forming tool curved cavity.