Publication Date:
2018-01-05
Description:
Boron nitride (BN) fibers were fabricated on a large scale through the melt drawn technique from low-cost boric acid, NH 3 and N 2 . Evolution of structure and properties of boron nitride fibers during the fabrication process was studied by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). The mechanical properties of the boron nitride fibers was tested and analyzed. The results shown that both the mechanical properties and the crystallinity of the boron nitride fibers were slightly increased with the temperature from 450°C to 850 °C, due to the combination of the fused-B 3 N 3 . For the BN fibers heat-treated at 850°C or 1000 °C, the tensile strength (σ R ) and elastic modulus ( E ) were strongly increased because of the increase of crystallization of BN phase. The meso-hexagonal BN fibers with a diameter of 5.0 μm were fabricated at 1750 °C, of which the tensile strength (σ R ) and elastic modulus ( E ) are 1200 MPa and 85 GPa, respectively. The BN fibers with excellent mechanical properties and proper diameters were obtained by the nitriding of the green fibers during their conversion into ceramic. This article is protected by copyright. All rights reserved.
Print ISSN:
1546-542X
Electronic ISSN:
1744-7402
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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