Authors: B. Chang, B.L. Gersten, S.T. Szewczyk and J.W. Adams
Affilation: Queens College, CUNY, United States
Pages: 369 - 372
Keywords: nanoparticle, nanorod, carbothermal reaction, boron carbide
Boron carbide (B4C) is an attractive material due to its extreme hardness, low specific weight, high chemical stability and good wear resistance. In this study, nano-sized boron carbide powders have been prepared through a carbothermal reaction process in a conventional high temperature furnace by using a mixture of boric oxide, amorphous boron powder and activated carbon black. The B4C products mainly consisted of spherical nanoparticles, however, small amounts of B4C nanorods and nanowiskers were also found. We found that adding Co catalyst in the precursor mixture could increase the yield of rod-like structure and it showed the diameter of the rods was defined by the size of the Co particles capped on the rod ends. The discovery of such varied morphologies in the reactant product by carbothermal method and the use of Co as a morphological agent were not noted in previous works. This has implications that B4C rod with controlled sizes could be prepared by the carbothermal reaction. XRD, SEM, EDX and TEM were employed to study the phase, morphology, stoichiometry and structure of the prepared nanopowders respectively. It is expected that B4C nanopowders, particularly those with controlled structures, will be useful in developing high performance ceramic composite.