Boron nitride fibers

Abstract

AbstractThe structure and properties of boron nitride fibers were examined. The fibers are polycrystalline consisting of a major phase of turbostratic boron nitride and a three‐dimensional ordered phase which is not hexagonal. The density of the fibers is determined by the amount of internal microporosity and crystal interlayer spacing. The existence of internal defects and necking‐down defects is described. The resistance of the fibers to refluxing water is shown to be closely related to the interlayer spacing. This effect of the crystal structure on the high thermal stability of the fibers is discussed. The mechanical properties are interpreted in terms of the microcrystalline structure. The electrical resistivity of BN fibers is compared to other insulators and arguments are presented to explain the difference between the conductivity of graphite and boron nitride.