Abstract: In a process for the manufacture of a hollow turbomachine blade in which die-forged and machined sheets are assembled and diffusion welded face to face after applying an antidiffusion coating to areas of the sheets where the assembly is to be expanded in forming the hollow blade, the welded assembly is subjected to a step of unsticking the coated areas of the sheets which are pressed together during the diffusion welding step, the unsticking step including subjecting the assembly to localized heating in a region where the intermediate sheet is provided with intercavity communication holes, and injecting pressurized gas into the welded assembly in a controlled manner to hot form a gas distribution duct in the locally heated region of the assembly to facilitate unsticking of the remainder of the coated areas. Apparatus for use in carrying out the unsticking step is also described.

Abstract: In a method of manufacturing a hollow blade for a turbomachine in which a plurality of primary sheet-like parts having anti-diffusion coatings in predefined areas are assembled face to face and diffusion welded together before being deformed to shape by pressurized gas and superplastic forming. The assembly, before being diffusion welded together, is subjected to a preheating treatment in an oven to remove the binder from the anti-diffusion coatings, and then, without moving the assembly, the interior of the assembly is evacuated while simultaneously progressively increasing the temperature at a rate V to a value T to produce a permanent plastic deformation of the parts, the interior of the assembly then being maintained in vacuo at the temperature T while an isostatic pressure is applied to the exterior of the assembly so as to produce a compacting of the anti-diffusion material and a prewelding of the facing areas which are not coated with the anti-diffusion material.