| 摘要 |
PROBLEM TO BE SOLVED: To provide a melting crucible, which is used with a casting crucible for glass bead production, capable of making a molten bath sufficiently smoothly flow and cut satisfactorily at casting. SOLUTION: The melting crucible 1, used for glass bead production with the casting crucible for heating a powder sample and a fusing agent into a molten bath and casting the molten bath into glass beads, is cylindrical in shape, with a bottom and made of an alloy of platinum as a principal component. Its upper end part 2 as an opening part has both an outer circumferential upper surface 4 which is continuous to the outside surface 3 and the inner circumferential upper surface 5 continuous to the outer circumferential upper surface 4 and an inside surface 6. The outer circumferential upper surface 4 is a surface of 0.3 mm or smaller in the radial direction in a horizontal plane, and the inner circumferential upper surface 5 is a curved surface in a shape, acquired by rounding an inner circumferential corner 8 of a cylindrical upper end part. COPYRIGHT: (C)2006,JPO&NCIPI
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