摘要 |
A method of forming a diffusion bonded joint during superplastic forming of a hollow metal structure (43) from sheet material (15, 16, 17, 18) using a two-piece die (1) having opposed clenching faces (9, 10) disposed along a split line (2) thereof, the structure 43 being formed with a joint at the split line, the method including placing the sheets (15, 16, 17, 18) between the faces (9, 10) clenching the sheets with a pressure sufficient to locate same during superplastic forming whilst being insufficient to deform the metal and prevent superplastic flow in the sheets between the clenching faces (9, 10), heating the sheets to a superplastic forming temperature and applying a gas pressure between the sheets to commence superplastic forming, when superplastic metal flow between the clenching faces substantially ceases upset forging metal from between the faces towards the interior of the die to increase wall thickness at the joint upon trimming off a flange formed by that part of the sheets trapped between the clenching faces. A die to carry out the above method, a die and sheet assembly and a structure manufactured according to the method are also provided. <IMAGE>
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