Abstract: An aerofoil structure with a hollow cavity is manufactured by diffusion bonding and superplastic forming. Outer panels are formed of a first material; a membrane is formed of a second material. Stop-off material is applied to preselected areas on at least one side of the membrane or of one of the panels so as to prevent diffusion bonding between the panels and the membrane at the preselected areas. The panels and the membrane are arranged in a stack and a diffusion bonding process is performed to bond together the first and second panels and the membrane to form an assembly. A superplastic forming process is performed at a forming temperature to expand the assembly to form the aerofoil structure. The forming temperature is selected so that the second material undergoes superplastic deformation at the forming temperature and the first material does not undergo superplastic deformation at the forming temperature.

Abstract: An aerofoil structure with a hollow cavity is manufactured by diffusion bonding and superplastic forming. Outer panels are formed of a first material; a membrane is formed of a second material. Stop-off material is applied to preselected areas on at least one side of the membrane or of one of the panels so as to prevent diffusion bonding between the panels and the membrane at the preselected areas. The panels and the membrane are arranged in a stack and a diffusion bonding process is performed to bond together the first and second panels and the membrane to form an assembly. A superplastic forming process is performed at a forming temperature to expand the assembly to form the aerofoil structure. The forming temperature is selected so that the second material undergoes superplastic deformation at the forming temperature and the first material does not undergo superplastic deformation at the forming temperature.

Abstract: An assembly configured to modify a surface or feature of a workpiece by hot isostatic pressing. The assembly comprising: a flexible membrane adapted to at least partially form an enclosure around the workpiece; and a former for placement adjacent to the workpiece, the former being configured to modify the surface or feature of the workpiece. A method of modifying a surface or feature of a workpiece, the workpiece having been previously formed by an additive manufacturing technique, by hot isostatic pressing. The method comprising: placing the previously-formed workpiece adjacent to a former adapted to modify the surface or feature of the workpiece; enclosing the workpiece in an enclosure at least partially formed by a membrane; and performing a hot isostatic pressing process on the workpiece.

Abstract: An assembly (10) for forming an object from a workpiece (40) by hot isostatic pressing, the assembly comprising: a flexible membrane (20) adapted to at least partially form an enclosure around the workpiece; and a former (30) for placement adjacent to the workpiece, the former being configured to form a surface (42) of the object. A method of forming an object from a workpiece (40) by hot isostatic pressing, the method comprising: placing the workpiece adjacent to a former (30) adapted to form a surface (42) of the object; and enclosing the workpiece in an enclosure at least partially formed by a flexible membrane (20).