Structure and Properties of the Directionally Crystallized B4C–NbB2–SiC Alloy

Abstract

The 32B4C–30NbB2–38SiC composite (mol %) has been prepared by the floating zone melting method. The structure of the obtained composite consists of a coarse-grained binary eutectic (NbB2–SiC), a fine-grained ternary eutectic (B4C–NbB2–SiC), and large SiC dendrites. The effect of the crystallization rate on the structure and properties of the prepared composite is studied. The Vickers hardness, fracture toughness, and bending strength of the 32B4C–30NbB2–38SiC composite are 31–36 GPа, 4.0–5.1 GPа m1/2, and 203–252 GPa, respectively.