Abstract: An electrical exceptance heater or igniter 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 particulate size within the range of magnitude of ten to three hundred microns. Upon its initial formation, the shape or element 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.
Type:
Grant
Filed:
September 27, 1979
Date of Patent:
May 4, 1982
Assignee:
Emerson Electric Co.
Inventors:
Frank J. Hierholzer, Jr., John A. Ancona, Gerald L. Shelton