| 摘要 |
<p>A coherent shape of a composition characterized by having a core bonded by regrowth of silicon carbide is produced by heating particulate silicon carbide which may be mixed with a minor amount of modifying agent, by means of an uncharged beam of energy, to a temperature above 3000.degree.F. and below 5500.degree.F. and subsequently cooling the resultant coherent shape below 3000.degree. F., both steps being completed within a period of ten minutes. In the preferred method, unconsolidated particulate silicon carbide is exposed to the energy of a laser beam and the particulate silicon carbide has a particle size within the range of magnitude of ten to three hundred microns. Upon its initial formation, the shape has a core and a distinctly delineated rind which is attached to the core. The core has a relatively low resistivity as compared with the rind. In an igniter formed by the use of a laser, the rind, which appears to be bonded together by quartz rather than by the regrowth of silicon carbide which characterizes the core, is removed, and the core, formed through at least a part of its reach in a serpentine pattern, is densified.</p> |
