Patent ID: 7237709

Claim:
A method of manufacturing an article of predetermined finished profile by diffusion bonding and superplastic forming at least two metal workpieces and two metal blocks comprising the steps of: (a) forming at least two metal workpieces, each metal workpiece has at least one surface, (b) forming two metal blocks, (c) arranging each metal block adjacent to an end of the at least one surface of a respective one of the at least two metal workpieces, (d) applying heat and pressure across the thickness of each metal block and the respective one of the at least two metal workpieces to diffusion bond the metal block and the respective one of the at least two metal workpieces together to form two integral metal preforms, (e) applying heat and forming the two integral metal preforms such that metal block and the end of the metal workpiece of each integral metal preform are formed such that a continuation of the remainder of the at least one surface of the respective metal workpiece extends through and across the metal block, (f) machining the metal block of each integral metal preform such that the new surface of the metal block is aligned with the remainder of the at least one surface of the respective metal workpiece, (g) applying a stop off material to prevent diffusion bonding to preselected areas of at least one of the surfaces of at least one of the at least two metal workpieces of the two integral metal preforms, (h) assembling the at least two integral metal preforms into a stack relative to each other so that the metal blocks are between the metal workpieces and the surfaces of the at least two metal workpieces and the two metal blocks are in mating abutment, (i) applying heat and pressure across the thickness of the at least two integral metal preforms to diffusion bond the at least two integral metal preforms together in areas other than the preselected areas to form an integral structure with a region of increased thickness, (j) heating the integral structure and internally pressurising the integral structure to cause the preselected area of at least one of the metal workpieces to be hot formed to produce a hollow article of predetermined shape.