Preparation of B₄C-ZrB₂-SiC ternary eutectic composites by arc melting and their properties

B₄C-ZrB₂-SiC composites were synthesised by arc melting in Ar atmosphere using B₄C, ZrB₂ and β-SiC powders as starting materials. The ternary eutectic composition of 40B₄C-20ZrB₂-40SiC (mol-%) was first identified and a lamellar eutectic texture was observed. SiC and ZrB₂ grains about 1 μm in thickness were uniformly dispersed in B₄C matrix of B₄C-ZrB₂-SiC eutectic composite. B₄C (003) and ZrB₂ (100) planes were perpendicular to the growth direction. The Vickers hardness of B₄C-ZrB₂-SiC ternary eutectic composite was 30-34 GPa. The fracture toughness of B₄C-ZrB₂-SiC composite increased with the decrease of B₄C content and the rise of ZrB₂ content.