# US 2021/0171184 A1 · Superplastic formed and diffusion bonded structures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0171184 A1 - Document ID: US20210171184A1 - Status: Published application - Kind: A1 - Application number: 16/557,613 - Filed: 2019-08-30 - Published: 2021-06-10 - Earliest claimed: 2019-08-30 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Corey Vasel - Web page: https://patentgrep.com/patent/US20210171184A1 ## CPC - B64C 3/36: Structures adapted to reduce effects of aerodynamic or other external heating - B32B 3/12: characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure - B32B 15/01: all layers being exclusively metallic {(making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00)} - B64C 3/20: Integral or sandwich constructions - B64C 3/26: Construction, shape, or attachment of separate skins, e.g. panels - B64G 1/58: Thermal protection, e.g. heat shields - B32B 2250/03: 3 layers - B32B 2250/40: Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA - B32B 2605/18: Aircraft - B64C 30/00: Supersonic type aircraft - B64C 2001/0081: {from metallic materials} - B64G 1/22: Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles - C22C 14/00: Alloys based on titanium - B64C: AEROPLANES; HELICOPTERS - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B64G: COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR - C22C: ALLOYS (treatment of alloys C21D, C22F) ## Abstract An exterior panel is configured to accommodate high thermal stresses imposed on exterior surfaces of aerospace transport vehicles during hypersonic flight. The exterior panel is formed of a superplastic material such as a titanium alloy, and includes an exterior skin and a plurality of cooling tubes that extend through the panel. The exterior panel further includes an interior skin configured to be attached to a frame member such as a rib, stringer, or spar of the transport vehicle. The tubes pass through a multicellular core, which is sandwiched between the exterior and interior skins to impart tensile and compressive strength to the exterior panel. In one disclosed method, the core is superplastic formed and diffusion bonded to the exterior skin, the tubes, and the interior skin. A cooling fluid, which may be a gas or liquid, including a fuel, may be pumped through the tubes to cool the exterior panel. ## Claims ### Claim 1 An exterior panel for a transport vehicle, the exterior panel comprising: an exterior skin configured for atmospheric exposure; an interior skin configured for attachment to a structural frame member of the transport vehicle; a multicellular core sandwiched between the exterior skin and the interior skin; and a tube extending through the multicellular core, the tube being configured for conveyance of a cooling fluid, wherein the multicellular core is superplastic formed and diffusion bonded to the exterior skin, and the interior skin. ### Claim 2 (depends on 1) The exterior panel of claim 1, wherein the tube underlies the exterior skin, and is diffusion bonded thereto, and wherein the tube traverses and is integral with the multicellular core adjacent the exterior skin. ### Claim 3 (depends on 1) The exterior panel of claim 1, wherein the exterior skin, the interior skin, and the multicellular core, are formed of a titanium alloy. ### Claim 4 (depends on 3) The exterior panel of claim 3, wherein the titanium alloy is a superplastic capable titanium alloy. ### Claim 5 (depends on 1) The exterior panel of claim 1, wherein the cooling fluid is a fuel. ### Claim 6 (depends on 1) The exterior panel of claim 1, wherein the tube is configured to convey a cooling gas or a liquid to remove heat from the exterior panel. ### Claim 7 (depends on 1) The exterior panel of claim 1, wherein the exterior panel is secured to a wing of the transport vehicle. ### Claim 8 A transport vehicle having at least one exterior panel, the at least one exterior panel comprising: an exterior skin configured for atmospheric exposure; an interior skin configured for attachment to a structural frame member of the transport vehicle; a multicellular core configured to impart tensile and compressive strength to the exterior panel, the multicellular core being sandwiched between the exterior skin and the interior skin; and at least one tube extending through the multicellular core, the tube being configured for conveyance of a cooling fluid, wherein the multicellular core is superplastic formed and diffusion bonded to the exterior skin, and the interior skin. ### Claim 9 (depends on 8) The transport vehicle of claim 8, wherein the transport vehicle is a hypersonic vehicle having a plurality of exterior panels, and wherein each exterior panel is joined to at least one other exterior panel by fusion welding. ### Claim 10 (depends on 9) The transport vehicle of claim 9, wherein each of the plurality of exterior panels includes at least one tube that underlies the exterior skin of that exterior panel, and is diffusion bonded thereto, and wherein the tube of that exterior panel traverses through, and is integral with, the multicellular core adjacent the exterior skin of that exterior panel. ### Claim 11 (depends on 8) The transport vehicle of claim 8, wherein the exterior skin, the interior skin, and the multicellular core of the at least one exterior panel are formed of a superplastic capable titanium alloy. ### Claim 12 A method of manufacturing an exterior panel for a transport vehicle, the method comprising: providing an exterior skin of a superplastic material configured for atmospheric exposure; providing a tube to be fixed proximate to the exterior skin; providing an interior skin of a superplastic material configured for attachment to a structural frame member of the transport vehicle; providing at least one core sheet of a superplastic material for forming a multicellular core between the exterior skin and the interior skin; and installing the exterior skin and the interior skin with the at least the one core sheet layer into a pressure containment device, supplying an inert gas into an expansion pipe to superplastic form and diffusion bond the skins and layers, creating a multicellular core that is integrally bonded to the exterior skin, the tube, and the interior skin; wherein the tube extends through the exterior panel. ### Claim 13 (depends on 12) The method of claim 12, further comprising bonding a second core sheet to the at least one core sheet via intermittent seam welds, securing the expansion pipe to one edge of the layers, and applying a continuous weld about the edges of the layers. ### Claim 14 (depends on 12) The method of claim 12, wherein the tube is configured for conveyance of a cooling fluid, including a fuel. ### Claim 15 (depends on 12) The method of claim 12, wherein the tube is secured to the exterior skin by fusion welding. ### Claim 16 (depends on 12) The method of claim 12, wherein the tube is formed of a titanium alloy. ### Claim 17 (depends on 12) The method of claim 12, wherein the tube is formed of a nickel alloy. ### Claim 18 (depends on 12) The method of claim 12, further including pressurizing the tube to avoid collapse thereof during superplastic forming and diffusion bonding of the multicellular core, to the exterior skin containing the tube, and to the interior skin. ### Claim 19 (depends on 12) The method of claim 12, further comprising a plurality of tubes, wherein the plurality of tubes are oriented parallel to one another. ### Claim 20 (depends on 19) The method of claim 19, further comprising spacing the tubes apart by a pre-determined distance prior to their securement to the exterior skin.