The Study on Carbon Nanofiber (CNF)-Dispersed B4C Composites

Volume 6 Issue 5, Pages 607 – 616

Ken Hirota, Yoshihiro Nakayama, Masaki Kato, Shingo Nakane, Toshiyuki
Nishimura
Published Online: Nov 5 2008 3:16PM

DOI: 10.1111/j.1744-7402.2008.02323.x

ABSTRACT
Carbon nanofiber (CNF)-dispersed B₄C composites
have been synthesized and consolidated directly from mixtures of
elemental raw powders by pulsed electric current pressure sintering
(1800°C/10 min/30 MPa). A 15 vol% CNF/B₄C
composite with ∼99% of dense homogeneous microstructures (∼0.40 μm
grains) revealed excellent mechanical properties at room temperature and
high temperatures: a high bending strength (σ_b)
of ∼710 MPa, a Vickers hardness (H_v)
of ∼36 GPa, a fracture toughness (K_IC) of ∼7.9 MPa m^1/2,
and high-temperature σ_b of 590 MPa at 1600°C in
N₂. Interfaces between the CNF and the B₄C
matrix were investigated using high-resolution transmission electron
microscopy, EDS, and electron energy-loss spectroscopy.

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