A hollow spherical article having at least two substantially diametrically opposed apertures in the spherical surface, said article being of wrought metal and having been moulded by explosive forming. The article may further comprise at least two cylindrical portions, said portions being located on the spherical surface and defining said apertures. The method of forming the hollow spherical article comprises placing a tube of wrought metal into a die, positioning a plurality of explosive charges within the tube and detonating the explosive charges to expand the tube to form said hollow spherical article having two cylindrical portions which may subsequently be removed by machining.
A method of correcting deformed turbine components (1) in an incompressible medium (4) is achieved via means of a pressure wave (6). The turbine component (1) is rigidly fixed to a matrix (3) containing a specified mold (2) and is put into the incompressible medium (4). The method may advantageously work at ambient temperature. It is quick, reproducible and cost-effective.
There is disclosed a method of forming a furnace cooling element involving casting a metal block or plate (10) around one or more elongated metal tubes (11) which have a protective coating applied thereto, and thereafter the, or each, metal tube (11) is explosively expanded by an explosive charge (12) closer to the surrounding material of the metal plate (10). Also disclosed is a method in which the protective coating on the metal tube is replaced by a full length external shroud tube (21) to increase the thermal efficiency of the cooling element, the inner metal cooling tube (20) is explosively expanded by an explosive charge (23) closer to the surrounding shroud tube (21) prior to casting a metal plate or block (28) around the tube combination (20, 21) to minimize the gap (22) between the outside wall of the metal cooling tube (20) and the inside wall of the metal protective shroud tube (21). Following casting the metal plate or block (28), the metal cooling tube (20 ) is again explosively expanded closer to the protective shroud tube (21) by a further explosive charge (23').
In a method of explosively expanding a tubular metal component into engagement with a surrounding metal component, an explosive charge is disposed axially and fired in an insert having a hollow cylindrical container fitting closely within the portion of the tubular metal component to be expanded and having charge holding device, for example an axial pocket, to accommodate the explosive charge, the container being filled with a shock wave-transmitting liquid. Compared with solid inserts, the novel hollow insert is cheaper and requires a smaller explosive charge for a given operation. The method is especially advantageous for expanding large diameter tubes.
Process and apparatus for expansion shaping of at least one localized region in a running portion of the wall of a tube of substantial length, wherein the distance between the expanded region and one of the ends of the tube is to be adjusted with precision; comprising disposing a die around the tube in the region to be shaped, the die comprising an expansion chamber between two cylindrical bearing surfaces, introducing a mandrel into the interior of the tube in the portion thereof which is within the die and delimiting an annular space between the mandrel and the tube, by two sealing regions disposed on respective sides of the expansion chamber at the location of the cylindrical bearing surfaces of the die, introducing a pressure fluid through the mandrel into the annular space, and increasing the pressure of the fluid until the tube becomes deformed against the walls of the expansion chamber.
