Mechanical properties of B₄C–CrB₂ binary eutectic composites prepared by arc‐melting

Abstract

B 4 C-CrB 2 composites were prepared by arc-melting using B 4 C and CrB 2 powders as raw materials. The eutectic composition of B 4 C-CrB 2 system was 30B 4 C-70CrB 2 (mol%) with a labyrinth-like irregularly layered eutectic microstructure, composed of B 4 C phase about 1-2 μm in thickness dispersing in CrB 2 matrix, much smaller than raw powders. The interface of the eutectic composite was well bonded, and there were edge dislocations at the interface to alleviate the interface mismatch. The eutectic temperature of B 4 C-CrB 2 composites was approximately 2200 K. At the eutectic composition, the B 4 C-CrB 2 composites showed the maximum Vickers hardness (24.6 GPa) and fracture toughness (4.3 MPa m 1/2 ) at room temperature.