| 摘要 |
1,154,240. Crystal-pulling. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 3 Oct., 1966 [6 Oct., 1965], No. 44103/66. Heading B1S. A rod of a constant diameter of 30-50 mm is pulled from a melt in a crucible by forming an image of the solidifying portion of the rod by the passage of y- or X-rays through the walls of the crucible and adjusting the degree of heating of the melt or the pulling rate to maintain constant the width of the image and hence the diameter of the rod. The crucible is simultaneously raised to maintain constant the level of the melt. The crucible and seed holder may be rotated. The controls may be effected manually or electrically. Conditions may be initially adjusted to form a conical shape using a thin seed and similarly at the end to withdraw all the melt from the crucible. The crucible may be of graphite having a quartz lining and a heat-insulating' graphite felt sheath. Heating may be by means of an induction coil having copper windows for passage of the rays. |
