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.

An axial load support member (17, 19, 28, 30, 32, 34, 38, 40) and method of manufacture achieves high load bearing capability with reduced weight and volume. A member is made by a process that includes providing at least three chamber profile preforms (2), each of which is comprised of a pair of deformable metal sheet walls (3) which bound a sealed internal chamber (14). After providing the preform the method includes in any order, a joining step and a fluid pressure delivering step. The joining step includes joining the at least three preforms together along a central member axis (4). The pressure delivery step includes delivering fluid pressure to the respective chamber of each preform such that the walls thereof are deformed and extend further away from one another with increased radial distance away from the central member axis.

An axial load support member (17, 19, 28, 30, 32, 34, 38, 40) and method of manufacture achieves high load bearing capability with reduced weight and volume. A member is made by a process that includes providing at least three chamber profile preforms (2), each of which is comprised of a pair of deformable metal sheet walls (3) which bound a sealed internal chamber (14). After providing the preform the method includes in any order, a joining step and a fluid pressure delivering step. The joining step includes joining the at least three preforms together along a central member axis (4). The pressure delivery step includes delivering fluid pressure to the respective chamber of each preform such that the walls thereof are deformed and extend further away from one another with increased radial distance away from the central member axis.

Hydroforming into a hollow structural component by pressing a joined plate member outwardly. A largest width is set to an area of a blank portion of the joined plate member extending to between outer peripheral portions of the recessed spaces from a longest constant portion of an internal space formed by the recessed spaces, the longest constant portion being constant in its inner circumferential length and extending the longest in the internal space. A width of an area of the blank portion extending to between the outer peripheral portions from a portion shorter than the longest constant portion is set such that the smaller the length of the portion which is shorter than the longest constant portion is compared to the longest constant portion. The smaller the width of the area extending from the shorter portion is compared to the width of the area extending from the longest constant portion.

Hydroforming into a hollow structural component by pressing a joined plate member outwardly. A largest width is set to an area of a blank portion of the joined plate member extending to between outer peripheral portions of the recessed spaces from a longest constant portion of an internal space formed by the recessed spaces, the longest constant portion being constant in its inner circumferential length and extending the longest in the internal space. A width of an area of the blank portion extending to between the outer peripheral portions from a portion shorter than the longest constant portion is set such that the smaller the length of the portion which is shorter than the longest constant portion is compared to the longest constant portion. The smaller the width of the area extending from the shorter portion is compared to the width of the area extending from the longest constant portion.

An apparatus for forming a panel, including a first face sheet, a second face sheet and a core sheet between the first face sheet and the second face sheet, may include a molding tool defining a forming cavity shaped to correspond to the panel, a heating system positioned adjacent to the forming cavity and configured to heat the forming cavity, and a pressurization system configured to pressurize a cavity volume between the tool and the panel and pressurize a panel volume between the first face sheet and the second face sheet.