| 摘要 |
<p>1372087 Making crystalline tubing ARTHUR D LITTLE Inc 1 Dec 1971 [14 Dec 1970] 55831/71 Heading BIS Crystalline refractory tubing which may be monocrystalline, is formed by moving relative to one another a preformed tube of refractory material and a heating zone maintained at a temperature sufficient to melt the refractory material, at such a rate as to form a continuously advancing molten ring of the material which is in contact with preformed and forming crystalline sections of the tubing. The heating zone may be positioned externally and/or internally of the tube. The source of the heat may be derived from infrared sources such as incandescent filaments, arcs imaged arc and lasers, electron beams, gas discharge systems and direct r.f. coupling. Many examples are given of both internal and external heating systems, including apparatus for carrying out these methods. The preformed tube may be made from alumina, thoria, zirconia, gallum arsenide, pseudobinary compounds such as AlAs-GaAs and elements such as boron and silicon. Tubing of alumina is exemplified.</p> |
