Intragranular Tungsten/Zirconium Carbide Nanocomposites via a Selective Liquid/Solid Displacement Reaction

摘要

A selective liquid/solid displacement reaction has been used, for the first time, to convert non-oxide ceramic solid solutions into composites comprised of intragranular metal nanoparticles embedded within non-oxide ceramic microcrystals. The reaction of (Zr_xW_(1-x)) microparticles with a Zr-Cu liquid at 1300℃ resulted in the formation of W/ZrC microparticles with a core-shell morphology. The internal microparticle core was comprised of W nanoparticles embedded within a single crystal ZrC matrix, whereas the W-free shell was comprised of an epitaxial layer of ZrC. Such a selective liquid/solid reaction process may be used to generate a variety of intragranular metal/ceramic-matrix composites.