| 摘要 |
Process for fabricating a superplastically formed trusscore structure from a pair of core elements each formed of a pair of metal sheets of a superplastic material, e.g. titanium. The sheets of each core element are welded together along pairs of closely spaced weld lines, one core element having an even number and the other core element an odd number of such pairs of parallel weld lines. A slot is provided between the weld lines of each pair of weld lines. The two core elements are placed together, with the pairs of weld lines of one core element displaced laterally, preferably midway between the pairs of weld lines of the other core element. Face sheets are applied in contact with the outer sheet of each of the core elements, and the periphery of the assembly is sealed as by welding. The resulting forming pack asssembly is placed in the cavity of a forming die. The die is heated to a temperature suitable for superplastic forming, and gas pressure is applied between the sheets of each core element and in the space between each of the face sheets, forming a plurality of successive substantially similar trapezoids. Additional pressure is then applied sufficient to cause diffusion bonding of adjacent contacting non-parallel sides of the trapezoids, and of adjacent contacting top and bottom surfaces of the trapezoids and the face sheets.
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