Abstract: A profiled tube (50b) comprising a high carbon content alloy (greater than 0.3%), superalloy or other high creep strength material, has a fluted bore with internal fins (52b) and intervening valleys or troughs (56b). Such a tube is made by centrifugal casting and subsequent electrochemical machining by drawing of an electrode (104) along the tube while at the same time passing electrolyte along the tube and around the electrode and also applying an electrical current between the tube and electrode, so that material of the tube passes into solution in the electrolyte. The electrode (104) has the same profile as the end-profile required in the tube (80) but has an inclined working face (124). An electrode rod (92) drives the electrode from one end mounting means (82) to another (84), each of which support the tube (80) and supply/exhaust electrolytic solution. The electrolyte is preferably sodium nitrate, although an acid based system is feasible.

Abstract: A profiled tube (50b) comprising a high carbon content alloy (greater than 0.3%), superalloy or other high creep strength material, has a fluted bore with internal fins (52b) and intervening valleys or troughs (56b). Such a tube is made by centrifugal casting and subsequent electrochemical machining by drawing of an electrode (104) along the tube while at the same time passing electrolyte along the tube and around the electrode and also applying an electrical current between the tube and electrode, so that material of the tube passes into solution in the electrolyte.

Abstract: A profiled tube (50b) comprising a high carbon content alloy (greater than 0.3%), superalloy or other high creep strength material, has a fluted bore with internal fins (52b) and intervening valleys or troughs (56b). Such a tube is made by centrifugal casting and subsequent electrochemical machining by drawing of an electrode (104) along the tube while at the same time passing electrolyte along the tube and around the electrode and also applying an electrical current between the tube and electrode, so that material of the tube passes into solution in the electrolyte. The electrode (104) has the same profile as the end-profile required in the tube (80) but has an inclined working face (124). An electrode rod (92) drives the electrode from one end mounting means (82) to another (84), each of which support the tube (80) and supply/exhaust electrolytic solution. The electrolyte is preferably sodium nitrate, although an acid based system is feasible.

Abstract: A method and apparatus for centrifugal casting a blank separable into a plurality of preforms having a required configuration for forging to a finished component. Individual molds are symmetrically located around the axis of rotation of a casting table and have mold cavities that are filled by molten alloy under the centrifugal force created by rapidly rotating the table. Alternatively, a cylindrical mold is centered on the axis of rotation and the centrifugal force created by rapidly rotating the table causes the molten alloy to fill cavities in the wall of the mold. Centrifugal forces of at least 20 g may be employed.