摘要 |
<p>A plurality of titanium sheets (42,44,46) are assembled into a stack (40). At least one of the sheets (44,46) is provided with a stop off material (56,58) on one of its surfaces (50,54) to prevent diffusion bonding at predetermined positions. The edges of the sheets (42,44,46) are welded together and a pipe (72) is welded to the stack (40) to interconnect with the stop off material (56,58) to form a sealed assembly. The assembly is heated and externally pressurised to diffusion bond the sheets (42,44,46) together. The integral structure so formed is heated and opposite ends of the integral structure are twisted relatively to contour the integral structure to a predetermined shape. The integral structure is internally pressurised to break the adhesive bonds. The integral structure is heated and internally pressurised to superplastically form one sheet to produce an article e.g. a fan blade. <IMAGE></p> |