An exterior panel is formed of superplastic materials, including an exterior skin of titanium to accommodate high thermal stresses imposed on hypersonic transport vehicles during hypersonic flight. The exterior skin is fixed to an underlying reinforcing skeletal structure consisting of a superplastic formable reinforcement (SFR) layer, for example a titanium, zirconium, and molybdenum (TZM) alloy, which supports the exterior skin whenever the latter may be heated to temperatures exceeding 1200 degrees Fahrenheit. The exterior panel includes a separate interior skin configured for attachment to a frame member such as a rib, stringer, or spar of the hypersonic transport vehicle. A multicellular core 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 and interior skins.

In some examples, a technique including positioning supports such that the supports are between a first metallic substrate and a second metallic substrate, wherein an undulating member is located between the first metallic substrate and the second metallic substrate, the undulating member defining a plurality of first peaks adjacent to a first surface of the first metallic substrate and a plurality of second peaks adjacent to a second surface of the second metallic substrate, wherein a first support of the supports is positioned such that the first support extends between a first peak of the plurality of first peaks and the second surface of the second metallic substrate; welding the first peak to the first surface of the first metallic substrate in an area of the first support; and removing the first support by at least one of a thermal removal process or a chemical removal process.

An exterior panel is formed of superplastic materials, including an exterior skin of titanium to accommodate high thermal stresses imposed on hypersonic transport vehicles during hypersonic flight. The exterior skin is fixed to an underlying reinforcing skeletal structure consisting of a superplastic formable reinforcement (SFR) layer, for example a titanium, zirconium, and molybdenum (TZM) alloy, which supports the exterior skin whenever the latter may be heated to temperatures exceeding 1200 degrees Fahrenheit. The exterior panel includes a separate interior skin configured for attachment to a frame member such as a rib, stringer, or spar of the hypersonic transport vehicle. A multicellular core 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 and interior skins.

A joule-heating press and method for manufacturing a metallic honeycomb core via diffusion bonding. The method may include printing a pattern of strips of a stop-off material to surfaces of a plurality of sheets of metal at locations where diffusion bonding is not desired and stacking the sheets of metal together in a sequence for forming the honeycomb core. Then the method may include steps of pressing the sheets of metal together between two press plates made of conductive material and applying electric current to the conductive material of the press plates. This allows current to flow through a thickness of the sheets of metal and the sheets of metal are thereby diffusion bonded to each other via joule heating at locations absent the stop-off material. Finally, the method may include a step of expanding the sheets of metal into the honeycomb core.

A component is provided. The component includes a structure including a plurality of unit cells joined together, each unit cell of the plurality of unit cells having a mass density substantially similar to the mass density of every other unit cell of the plurality of unit cells. The plurality of unit cells includes a first portion of unit cells having a characteristic dimension and a first portion average stiffness, the characteristic dimension of the first portion of unit cells having a first value. The plurality of unit cells also includes a second portion of unit cells having the characteristic dimension and a second portion average stiffness, the characteristic dimension of the second portion of unit cells having a second value different from the first value, wherein the second portion average stiffness differs from the first portion average stiffness.

In some examples, a technique including positioning supports such that the supports are between a first metallic substrate and a second metallic substrate, wherein an undulating member is located between the first metallic substrate and the second metallic substrate, the undulating member defining a plurality of first peaks adjacent to a first surface of the first metallic substrate and a plurality of second peaks adjacent to a second surface of the second metallic substrate, wherein a first support of the supports is positioned such that the first support extends between a first peak of the plurality of first peaks and the second surface of the second metallic substrate; welding the first peak to the first surface of the first metallic substrate in an area of the first support; and removing the first support by at least one of a thermal removal process or a chemical removal process.

A joule-heating press and method for manufacturing a metallic honeycomb core via diffusion bonding. The method may include printing a pattern of strips of a stop-off material to surfaces of a plurality of sheets of metal at locations where diffusion bonding is not desired and stacking the sheets of metal together in a sequence for forming the honeycomb core. Then the method may include steps of pressing the sheets of metal together between two press plates made of conductive material and applying electric current to the conductive material of the press plates. This allows current to flow through a thickness of the sheets of metal and the sheets of metal are thereby diffusion bonded to each other via joule heating at locations absent the stop-off material. Finally, the method may include a step of expanding the sheets of metal into the honeycomb core.