Superplastic forming and diffusion bonding process

• Main Authors: Robert William Greenhalgh, Howard James Price
• Format: Patent
• Language: English
• Published: 10.08.2022
• Subjects: CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; MACHINE TOOLS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; PUNCHING METAL; SOLDERING OR UNSOLDERING; TRANSPORTING; WELDING; WORKING BY LASER BEAM; WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS ORPROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL

In a process for superplastically forming and diffusion bonding a structure from a pack comprising a skin sheet 16, 18 and a core sheet 10, 12, venting grooves 182 are formed in a surface of one of the sheets that is adjacent to the other sheet, so that gas can be vented from between the sheets. The stack may be placed in a mould and the skin superplasically deformed, using an inert gas, onto the mould inner surface. The core sheet may then be deformed onto the formed skin sheet and gas between the sheets vented via the grooves. Continued pressure and heat applied after deformation of the core onto the skin results in a diffusion bond between them. The venting grooves may comprise interconnected loops such as circles or ellipses. A mechanical fastener may be located in an area of the structure within a loop of a venting groove. A venting groove may be formed in a flange of the structure. Gas may be injected between the mould and the skin to force the skin and core together. The pack may comprise a pair of core sheets bonded in selected areas and sandwiched between a pair of skin sheets.