초록 ▼

A superplastically formed, diffusion bonded sandwich structure having integral metal hardpoints, made by joining two superplastic metal core sheets together into a core pack by welding or diffusion bonding along a pattern of lines which form junction lines between the core sheets when the pack is in

A superplastically formed, diffusion bonded sandwich structure having integral metal hardpoints, made by joining two superplastic metal core sheets together into a core pack by welding or diffusion bonding along a pattern of lines which form junction lines between the core sheets when the pack is inflated by gas pressure at superplastic temperatures. Face sheets are laid under and over the core pack and metal inserts are interposed between the face sheets and the core. All of the sheets in the pack are sealed together around an outside peripheral edge to create a gas tight envelope. The pack is heated to superplastic temperatures in a cavity in a die, and the top and bottom face sheets are diffusion bonded to top and bottom surfaces of the metal insert by application of heat and pressure from top and bottom inner surfaces of the die cavity. While at superplastic temperatures, the pack is inflated by gas pressure against inside surfaces of a die to form an expanded metal sandwich structure having integral webs and integral hardpoints formed by the metal insert. After forming, the gas pressure is reduced to near atmospheric, the die is opened and the part is removed from the die.

대표청구항 ▼

1. A method of making a superplastically formed, diffusion bonded sandwich structure with an integral metal hardpoint for attachment of said sandwich structure to other structure, comprising:joining at least three superplastic metal sheets together into a pack by welding or diffusion bonding along a

1. A method of making a superplastically formed, diffusion bonded sandwich structure with an integral metal hardpoint for attachment of said sandwich structure to other structure, comprising:joining at least three superplastic metal sheets together into a pack by welding or diffusion bonding along a pattern of lines which form junction lines between said sheets when said pack is inflated by gas pressure at superplastic temperatures; interposing at least one metal block insert between at least two of said sheets, said metal insert forming said hardpoint when said sheets and said insert are diffusion bonded together onto said insert; sealing all of said sheets in said pack together around an outside peripheral edge to create a gas tight envelope; heating said pack to superplastic temperatures and diffusion bonding at least two of said sheets to top and bottom surfaces of said metal insert inflating said pack at superplastic temperatures against inside surfaces of a die by injecting gas under pressure through a gas line in said peripheral edge to form an expanded metal sandwich structure having upper and lower face sheets in contact with said inside surfaces of said die, and having integral webs and an integral hardpoint formed by said metal block insert spanning the space between said face sheets and diffusion bonded thereto, thereby coupling said upper and lower face sheets and providing a load path between said face sheets through said metal block insert for forces exerted by fasteners connecting said sandwich structure to said other structure; venting said gas pressure, cooling said expanded metal sandwich structure, and removing said expanded metal sandwich structure from said die; and drilling holes in said sandwich structure in alignment with said metal insert through at least one of said sheets and into said metal insert for receiving said fasteners by which said sandwich structure can be attached to said other structure.