Formation of high-strength high-modulus coated filaments
Abstract
Abstract A SUBSTRATE OF CORE FILAMENT, OF RELATIVELY SMALL DIAMETER, IS HEATED TO AT LEAST 900*C. IN THE PRESENCE OF HYDROGEN, METHANE AND BORON TRICHLORIDE IN PRESELECTED PROPORTIONS TO PRODUCE A STRONG STIFF, RELATIVELY LARGE DIAMETER FILAMENT WHICH, APART FROM THE CORE, COMPRISES A 21-35% CARBON, REMAINDER BORON, COMPOUND ESSENTIALLY FREE OF FAULTS, CRACKS, GRAIN BOUNDARIES, ETC. PREFERABLY A TUNGSTEN SUBSTRATE FILAMENT ABOUT 1 MIL IN DIAMETER IS HEATED TO 900*C. AND THEN 1200*C. IN THE PRESENCE OF AN ATMOSPHERE COMPRISED, IN MOLE FRACTIONS, OF THE FOLLOWING: 0.605-0.686 HYDROGEN, 0.076-0.185 METHANE, AND 0.210-0.238 BORON TRICHLORIDE. AFTER SEVERAL MINUTES FILAMENTARY DIAMETERS ON THE ORDER OF 4-7 MILS ARE ATTAINED WITH FILAMENT PROPERTIES APPROACHING THOSE OF AMORPHOUS BORON CARBIDE.
Inventors
- 👤 John B Higgins
- 👤 Arno Gatti
Bibliographic Details
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