| 摘要 |
<p>979,711. Melting metals by combined iriduction heating and electron bombardment. W. C. HERAEUS G.m.b.H. May 23, 1961 [May 21, 1960], No. 18569/61. Heading H5H. [Also in Division H1] In a high vacuum induction furnace, in which the end of a suspended metal rod is surrounded and melted by a coil, the molten metal drops into a crucible maintained at a positive potential with respect to the rod, whereby the molten pool in the crucible is heated by electron bombardment, effecting degassing and the prevention of blow-holes. Rod 4 of the metal to be melted is held by a vertically adjustable rod 3 such that its end lies within induction coil 5 in the vacuum chamber 1, to the bottom of which crucible 6 is clamped. Block 12, of the same material as rod 4, is mounted on water-cooled plate 10 and progressively lowered, by adjustment of strut 11, as molten metal accumulates in the crucible. Coil 5, which is fed by a fluid-cooled coaxial conduit 20, is surrounded by a magnetic yoke 15 and a water-cooled non-conductive shield 16 coated on its inner face with a heatreflecting metal. The rod 4, coil 5, and shield 16 are maintained at the same negative potential with respect to the crucible, electrons emitted from the rod 4 being focused by coil 9, which also stirs the molten metal 17. The coil 9 and the crucible are water-cooled; the apparatus is applicable to the melting of titanium, zirconium, niobium, tantalum, molybdenum, and tungsten.</p> |
