Patent GB-500469-A (GB)
Title: Production of alloys containing beryllium
IPC: C22C1/02
Filed: 1937-07-05
Abstract: 500,469. Alloys ; specific gravity estimating - apparatus. BRUSH BERYLLIUM CO. July 5, 1937, No. 18659. Convention date, July 7, 1936. [Class 82 (i)] [Also in Groups XII and XX] Alloys of beryllium and at least one of the heavy metals (copper, iron, cobalt, nickel, chromium and mangenese) are made by introducing into a reaction zone heated to a temperature above 1600‹ C., at least one heavy metal, beryllimn oxide and carbon, the beryllium oxide employed being of such a degree of purity thatits apparent density does not exceed 0À5. A furnace, Fig. 1, for carrying out the reduction comprises an iron shell, 1 and a pot 2 formed of carbon blocks 2a, having a lining 2b formed by ramming g a mixture of powdered carbon and pitch and coking in situ, and thermally insulated from the shell by means of a mixture 3a of finely divided carbon and coarse resistor carbon, at the base, an finely divided carbon, fluffy beryllium oxide, or zirconia 3b at the sides. The furnace walls 4 above the pot may be formed of sillimanite or beryllium oxide. Cover plates 5, which may be of graphite or beryllium oxide, rest on the top wall of the pot 2. The part 4 of the walls is surrounded by a section 6 of granular beryllium oxide except at one side where an extension 4a is provided with a pouring-lip 4b having a graphite lining 4c. The top of the wall is covered by means of a plate 7 of a refractory which may consist of a mixture of cement and asbestos fibre. Carbon electrodes 8 are supported by water cooled metal carriers 9 adjustably supported at 10, 11. The electrodes extend through elongated apertures 5a in the plates 5. A third water cooled electrode 14 is attached to the bottom of the furnace. The furnace is supported on trunnions 16. The materials of the charge are weighed out and milled in a ball mill lined with silica, the heavy metal used or rubber, the balls being formed of the heavy metal. The charge which may have been dried by preliminary heating at 150-200‹ C., or by maintaining it in a dry atmosphere is fed intermittently through the aperture 5a between the olectrodes. Nitrogen or coal gas may be introduced. Alternatively,- the crucible may be formed of beryllium oxide or zirconia and an induction or resistance furnace employed. The alloy may be purified by transfer to a pot lined with graphite or carbon in which it is quickly cooled by contact with skimmings or previously purified alloy; the alloy is stirred or washed with hydrogen or an inert gas, or subjected to a vacuum to remove gases, and poured into a graphite-clay crucible maintained at 1000-1100‹ C. ; coke is added and the alloy allowed to stand for 30-45 minutes after which the coke is removed and the alloy skimmed and poured into moulds. The skimmings are broken up and fed to the furnace or transfer pot. A copper-beryllium . alloy containing 4-5 per cent of beryllium may be so produced. By melting with copper and nickel, a bronze containing 2“ per cent of beryllium may be produced, the dross being fed to the furnace as a source of beryllium oxide and copper. Alloys containing magnesium and aluminium in addition to beryllium and a heavy metal may be pruduced. Pure beryllium oxide may be prepared from beryl as described in U.S.A. Specification 2,018,473. The apparent density of beryllium oxide is determined by passing it through an 80 mesh screen, allowing it to fall into a refractory bout and heating for ten minutesin an atmosphere not more strongly reducing than hydrogen ; an amount of oxide slightly greater than is required to fill a weighing bottle 19, Fig. 5, is then placed on a screen 17b and brushed through so as to fall through the funnel 18 without packing into the bottle ; the excess is scraped off and the bottle, of known volume, weighed. Preferably, the apparent density does not exceed 0À4.