GB839556A - Improvements in or relating to casting - Google Patents

Abstract

839,556. Casting-machines. BRENNAN, J. B. Aug. 30, 1956 [Oct. 10, 1955], No. 26513/56. Class 83 (1). A casting method comprises feeding molten metal into a cavity in a passage, the extremes of the cavity being defined by two plugs, and moving the plugs to carry the material along the passage to eject it from the passage in a shaperetaining form. Molten or solid metal in particulate form is fed to an electricallyheated container 1, and degassed by maintenance of a vacuum therein. A die 7 extending downwardly from the container has a zone heated by a high-frequency coil 8 and a zone cooled by a cooling unit 9. Extending upwardly and vertically reciprocable through the die, is a rod 10 which defines the lower end of the casting to be made, and extending downwardly is a vertically reciprocable sleeve member 15 defining the upper end of a tubular casting, whose interior surface is defined by an independently vertically reciprocable rod 18. Thus when the mould ports 10, 15, 18 are moved downwardly in unison, a casting is carried through the die 7. Downward movement of the core 18 may then be stopped, so that the member 15 strips the solidified casting from the core, relative movement of the members 10, 15 then freeing the casting for lateral removal, e.g. by air-blast 21. During passage through the die the member 15 may be moved downwardly relative to the members 10, 18 so that the casting is compressed during solidification. The core 18 may be omitted and the part 15 may be solid to produce solid castings. Further, a series of wires may be cast by having grooves in the die 7 or around an enlarged head of the core 18, with the member 15 arranged to longitudinally strip the cast wires from said grooves. Mould and core materials.-The parts 10, 15, 18 are preferably made of Al 2 O 3 ,nitridedsilicon-carbide, quartz or graphite, and the die 7 is of graphite. Casting processes.-In an example, copper in the container is maintained at a temperature of about 2150-2300‹ F.